Tranny Project: Inspection and evaluation

User1 · Sep 11, 2008

<TABLE cellSpacing=1 cellPadding=6 width="100%" border=0><TBODY><TR><TD colSpan=2><TABLE width="100%" border=0><TBODY><TR><TD style="PADDING-TOP: 4px" vAlign=top colSpan=2>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Tranny Project: Inspection and evaluation

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 2 2000 at 9:09 PM[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT> [/FONT]</TD></TR><TR><TD vAlign=bottom colSpan=3><HR></TD></TR><TR><TD colSpan=3>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Mac,

Regarding your question about the wear on reverse, it sounds normal. A little rounding of the edges (on the end towards the splines) is OK. Don't worry about the ends of the teeth, reverse is a "straight cut" gear.

For evaluation we will start with 5th and work our way down. 5th, 4th and 3rd all use the same "Porsche" type synchros, so the same proceedure will work on all of them. On the gear itself you will find two sets of teeth. The broad flat teeth that contact the corresponding gear on the driven shaft should have little or no wear. Inspect them all for pitting and gauling. The teeth will normally have signs of polishing on their face, this is normal. Also check for debris trapped between the teeth. Little pieces of metal can be forced in between and trapped. Usually it can be removed with a pick. Next, examine the smaller teeth that engage the slider. These are on the edge or side of the gear and should have been cut to a point. They engage the sliding sleeve and are the ones that affect shifting. The points can be worn off or rounded with wear. If the points are still evident the gear is fine. Typically you can compare these teeth between the different gears to get an idea of what they should look like. Usually, 3rd has wear and 4th and 5th are like new. Sometimes two or all three can be worn. If the points are rounded compare the length of the teeth with another gear that still has good points (assuming you have one). The teeth should still be about the same length even with the points rounded slightly. If the teeth are noticably shorter, the gear needs to be replaced. This will be most important with 3rd as it gets most of the wear. Typically 5th is in good shape, so you might want to use it as your reference.

Now examine the sliding sleeves. Note that 5th has its own sleeve (with teeth on only one side). Test fit the slider to a gear to note how the teeth mesh. Examine the teeth on the side for the same points as on the gear. Typically you will see the most wear on the side of the slider that faces 3rd. Again the wear appears as a rounding of the teeth. Compare the length with the teeth on the other side (facing 4th, or on the 5th slider) for reference. If the teeth are worn down to the level of the side of the slider, it must be replaced. For a reference, test fit each side of the slider to both 3rd and 4th gears and compare the amount of overlap on the teeth. Then try turning each component the opposite direction and see how far you must pull them appart before they slip. This is where all of the engine power is delivered to the rear wheels when in that gear. The more overlap in the teeth, the more positive the shift. The less overlap, the easier it is to miss the shift and the more likely to pop out of gear. The final item for the gear and slider is the slider's inner teeth. You will notice the slider's teeth are on the inside of the sleeve. These teeth have a broad, flat face. They are machined with three distinct sections; the outter section is tapered to contact the synchro (on each side of the slider) and the center section has a slight depression to capture the synchro when fully engaged.

To check the slider, re-install a synchro on 3rd gear, with its locks and snap ring. Then test fit each side of the slider to the gear. The flat inner face of the teeth should contact the surface of the synchro ring before the engagement teeth have any overlap. This is how the synchro spins up before the teeth mesh. If the teeth mesh before the synchro makes full contact with the slider, you get the dreaded crunch. Try both sides of the slider for comparison. Do the same with 4th gear and compare its action with 3rd. If one side of the slider must consistantly cover more of the synchro to get any resistance from the synchro, that side has more wear. Now examine the teeth faces on each side of the slider and look for evidence of wear. Usually, if the teeth face and synchro have noticable wear, the engagement teeth have the points worn off anyway.

Finally, examine the synchro rings themselves. As noted earlier, it is normal to see some wear, as polishing, at the gap. Compare each gears synchro with the others. The further around the ring the polishing goes, the more wear. Also, note from your test fitting the slider earlier, which synchro gave the slider less resistance. Another good comparison is to examine the side of the synchro that was facing the slider and compare it to the side facing the gear. If there is a noticable difference in the texture and taper, the synchro should be replaced. Or if the polishing at the gap extends more than 1/4 to 3/8 inch in either direction from the gap, replace it. If the synchros (especially 4th and 5th) look to be in good condition they can be re-used.

The synchros for 1st and 2nd are "ring" type (also known as 'hub' type). First examine the main gear teeth as you did on the others. Then examine the smaller engagement teeth. Again, these should have neatly machine points. Some rounding is normal. Completely rounded is not and may require the gear be replaced. Note that beside the engagement teeth is a tapered hub with half a dozen narrow ribs on it. This is the synchro hub. Test fit the gear's synchro to its hub. The synchro is the ring (about 3" in diameter) with the blocks at the outter edge. The interior of the ring has a taper that matches the gear's hub. Using modest pressure, fit the ring over the hub while turning the ring. The synchro should grip the hub before bottoming out. If the synchro bottoms out and you can still turn it, try the same test with the other synchro. If it too bottoms out, try the same test with both synchros on the other gear.

What we are trying to determine with this test is whether it is the synchro or the hub that is worn out. If you have a synchro that bottoms out on both hubs, and one that doesn't, then you have a worn out synchro. If you have both sychros that bottom out on one hub and not the other, then you have a worn out hub. If the hub is worn out the gear must be replaced.

(Mac, since you have a suspicion about 2nd gear in your transmission, pay special attention to the 2nd gear hub and synchro.)

In those rare cases where both synchros bottom out on both hubs. A new synchro should be used to determine the condition of the hubs.

I typically like to see a measurment of about 50/1000 clearance before the ring bottoms out on the hub. 30/1000 or less and I would replace the synchro.

Now we turn out attention to the 1st/2nd slider. The engagement teeth are on the interior of the slider. As before we are looking for fresh points on the teeth. And, as before, some rounding is normal. If the teeth's ends are beat up and completely rounded, the slider (like the gears) should be replaced. The 1st/2nd slider has teeth on the outside of the sleeve as well. This is reverse. On the 5 spd, the edge of the teeth next to the fork's groove is what is important, (on the 4 spd it is the edge away from the fork's groove). This is the side of the teeth that engage with the reverse idler. These teeth are cut with a slight taper at the edge. If they are uniform, without much rounding, the slider is usable.

Now examine the 1st/2nd slider's hub components. The hub itself is almost bullit proof. But you need to examine the three little metal inserts for pitting or dents. They should be find. Also examine the two ring springs that hold them in place. This is a thin wire ring with a gap and three little kinks or dimples (to retain the metal inserts). If a spring is broken or bent, it must be replaced.

Finally, check the reverse idler. It too has a slight taper to the cut of the teeth (opposite of the side with the groove for the fork). Again we are looking for fresh points on the teeth, but some rounding is normal.

Note: I have seen reverse in these transmissions in terrible shape. I have seen the teeth on the idler, the outside of the slider and on the driven shaft, worn almost completely off. Sometimes as much as 3/4th of the teeth gone. Because these are not sychromesh gears you can get a way with a lot more wear on the 3 reverse components than on any other gear. Just remember to be gentile with it.

Mac, you noted the bearing race on the end of the lay shaft was hashed. What does it look like? If it has a dull or pitted surface, it is. You will need to check the rollers in the bearing itself too. It may need to be replaced as well. Usually you can heat the race with a lighter or small torch and pull it off with a pair of pliers. Or use a high quality chisle and carefully drive it off.

Next time we will inspect and prepare the cases and linkage.

Steve


[/FONT]</TD></TR></TBODY></TABLE><TABLE cellPadding=4 width="100%" border=0><TBODY><TR><TD vAlign=top noWrap align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial] [/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]

[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Author[/FONT]</TD><TD>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Reply[/FONT]</TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Gilles[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 15px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Very impressive Steve...are we lucky or what?

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 3 2000, 9:28 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 15px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]N/T

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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mac <NOSCRIPT> Mac </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 30px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]I, for one, am grateful beyond words <nt>

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 3 2000, 7:19 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 30px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<CENTER>

</CENTER>

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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Gilles[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 45px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]experience, experience...

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 4 2000, 8:20 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 45px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Mac:

No matter how good the shop repair manual may be, because definitely there is not substitute for experience, and that is what separates the good mechanics from the rookies (do we qualify here?)

What we got here is access to priceless information, which will allow us to learn from other person experiences without paying the expensive mistakes of the learning curve.

Boy, do I love this site...


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mac <NOSCRIPT> Mac </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 15px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]final drive question

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 5 2000, 11:21 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 15px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]I'm not trying to get ahead of myself here, but am curious - how does one determine which final drive is present in the tranny?

It is an '83 trans and was virtually new when I got it in the winter of '98, thus it is likely the stock ratio for '83, - but it was all in pieces when I bought it, then assembled and put in the '80 X, sooo in theory it could be any one. I was so impressed with the apparent newness of it all at that time, that (like a dumbarse) I didn't even think to ask which final drive was in there. I didn't care, I was just glad to get my hands on it!

So anyway my ultimate question is: do I just count the teeth, or do these part #s on the drive gears indicate which it is? -Mac.



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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 30px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Final drive ratios

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 6 2000, 11:39 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 30px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Mac,

All X1/9 5 spds had the same 4.08 final drive gear. If you want to count, then you should find, 13 teeth on the pinion and 53 teeth on the ring. Anything else, let me know!

What would be of interest is the ratio for 1st and 3rd gear. This will tell us which gearset you have in the car. There were three different ratio sets. If the teeth on 3rd gear are fine cut like they are on 4th and 5th, then you have one of the two later ratio sets. If 3rd is cut like 1st and 2nd, then you have the early ratio set. If the gearbox you have is an '83, then it should be the middle gearset.

Steve


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mike Mittelstead <NOSCRIPT> Mike Mittelstead </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 45px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Ratio Question

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 6 2000, 11:31 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 45px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Howdy. I've heard that there are some differences in the 5 speed gear ratios, but am curious as to what they are.

Can you tell us what the differences are, and what years they were used?

Also, a 4 speed question. I have a 3rd gear that has the larger diameter syncro. Was this used only in the '78 X? Will it last longer or shift better than the standard diameter syncro?

Fortunately, the little syncro teeth are in great shape, and I already have a new set of that size syncro rings (tho' the originals were barely worn). I have the shifting fork for the larger diameter slider (putting it into a '74 tranny with the worst looking third gear I ever saw).

ThanXalot, MM/OR

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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Mac[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 60px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]I have some info, but could use some more...

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 9:05 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 60px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]This IAI Bertone shop book lists only 2 of the 3 different 5-speed gear sets...

Here's what it has to say:

1979 - 1980 ratios (to 1)
1st = 3.583
2nd = 2.235
3rd = 1.454
4th = 1.042
5th = 0.863
Rvs = 3.714

1981 - 1982 ratios (to 1)
1st = 3.583
2nd = 2.235
3rd = 1.461
4th = 1.033
5th = 0.863
Rvs = 3.714

...and it does not say beyond '82, which figures since mine has "83" cast into the case D'oh!~

By the way, the other book (Fiat 1300 manual) lists the 4-speed as:

1974 - 1978 ratios (to 1)
1st = 3.583
2nd = 2.235
3rd = 1.454
4th = 0.959
Rvs = 3.714

So can anyone say what are the ratio differences in the '83 and later trannies? Just curious -Mac.



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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 75px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]5 spd gearsets

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 8:19 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 75px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]The two 5 spd gearsets Mac listed are correct. I don't have any data on '83+. I do know that the '87 and '88 gearsets had a shorter 1st (a real stump-puller) and a (very) slightly shorter 3rd. I have the ratios written down somewhere, but I don't have documentation on them.

I put an '87 gearset in my '87 X (funny how that worked out) and hated it. 1st was so short it was annoying. I swapped it for a '79/'80 gearset and was much happier.

There may actually be a 4th gearset, although I haven't seen one. I have at least one of each of these three gearsets right now. Thing is, the differences are all so subtle as to be almost pointless.

Steve


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mike Mittelstead <NOSCRIPT> Mike Mittelstead </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 90px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Subtle, pointless differences in ratios

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 8:40 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 90px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Yes, after seeing Mac's numbers, the differences are slight. Any thoughts on why Fiat changed the ratios these tiny amounts? (Other than to foil would-be parts swappers 20 years later). MM 

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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 105px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Some ideas

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 8:59 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 105px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Just speculating but: The original 5 spd gearset was just a 4 spd ratio set with 5th added on. Then the car was upgraded with fuel injection, etc... and someone got the idea that perhaps the extra torque could pull a wider 3rd/4th gap. I noticed too that the later model gearsets have fine cut teeth on 3rd in addition to 4th and 5th. Perhaps they switched to the Uno gearset on the later boxes. The fine cut gears are more expensive to machine, but are quieter and more efficient.

Steve


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 60px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]4 spd synchros

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 8:11 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 60px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]The large diameter 3rd/4th synchro appeared in the '78 4 spd. This is the same diameter synchro as in the 5 spd. You could upgrade to the larger diameter. It would require both 3rd and 4th gears (with the larger diameter synchro), a pair of synchros, the slider and its hub and the selector fork.

In theory, the larger diameter synchro should give better performance and longer life than the smaller diameter synchro. Although I haven't doen a back to back comparison in the same tranny, I personally can't tell much difference from the driver's seat.

If I had a choice though, I would put it in. Right now I am considering that the next 4 spd I build for one of my cars, I will use the Yugo gearset. It uses a complete 5 spd gearset configuration only leaving off 5th. Kind of neat.

Steve


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Mark Freeman[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 45px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]other final drive ratio?

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 4:04 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 45px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]I'm digging deep in the memory banks but I seem to recall that a '79 i once had was equiped with a lower final drive ratio - something like 4.42:1 sticks in my head. Did these exist?

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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mac <NOSCRIPT> Mac </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 60px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]ratio roundup

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 4:21 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 60px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Now this is getting weird! Just got off the phone with Vick's. I was told there are 4 different variations in X 5-speed gearsets!

They said there was a "'79 only" set, a different set which ran from '80 to '81, a third which was from '81 to '84 or '85, and a fourth set used after that!

I had not heard that before, I thought there were only 3 variations. Anybody heard of the 4th one? -Mac.



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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 60px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Nope

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 7:53 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 60px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]The 5 spd only had the 4.08. The 4 spd had the 4.08 in '74 and the 4.42 from '75 - '78.

Steve


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mike Mittelstead <NOSCRIPT> Mike Mittelstead </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 75px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]4 speeds with 4.42 or 4.08?

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 8:33 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 75px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]On the '75-'78 4 speed, I have heard/read/been told that 4.42 final drive was used,
UNLESS the car had a catalytic converter or factory air.
In that case (pun), a 4.08 was used in the 4 speed to keep the cruising revs lower.

Truth, lie, or urban legend?

BTW, thanX for the dope on the '78 3-4 syncro.

MM/OR

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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 90px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Uhhh, well???

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 9:09 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 90px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]I would have expected that to be exactly backwards. You would want a shorter final drive to help the car lug around the AC and pull the compressor. A taller final drive would only make the car slower with AC.

As for the cat, don't know. I don't know what the cruise rpm would have to do with it. Back then they only did an idle smog test.

I can tell you that a 4 spd with a 4.08 is VERY rare. I have two, one from my '74 and one from my friend Dave's '74. My car now has a 4.42 and Dave's car now has a 5 spd (equipped with an aftermarket 4.82) But these are the only two I have EVER seen.

Steve


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mike Mittelstead <NOSCRIPT> Mike Mittelstead </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 105px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Guesses on 4.08/4speed gears

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 8 2000, 12:30 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 105px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]On the catlyst cars, the owner's manual states that the cat was subject to overheating at sustained high RPMs, so they got the higher gears and a red light on the dash that warns of an overheating cat with the warning to SLOW DOWN.

On the AC cars, I'll just guess that big honkin' cast iron compressor couldn't handle sustained high revs. A lower ratio AC pulley would work instead, but then it probably would have not circulated Freon adequately at lower rpms. Just a SWAG.

On the rarity, I think that the cats were for passing stricter OE Calif emmissions controls, and there are now probably fewer Calif cars in Alabama than the west coast. And there are probably fewer wussies that need AC in Alabama than in Calif. Do you see many early Xs with cats in Alabama?

My '76 with cat definitely has the 4.08s. All stock and dog-slow. MM


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 120px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Hmmmm...

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 8 2000, 6:19 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 120px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]I had a '75 with a Cat. It was bought new in Alabama from the local dealer. I was the second owner. It had the "slow down" light in it too, but also a 4.42 gear. I also had a '77 that was a non-cat, no air. It had a 4.42, but it was built late in '77 and had a '78 spec motor in it. I later had a '78 with a cat, with air and it had a 4.42. I had a couple of others too, but can't remember what the original config was.

I haven't seen any documentation on what cars had what gear, except that all '74s had the 4.08. I remember reading that the '75s were switched to the 4.42 to pickup the performance losses from the smog pumps.

My experience has shown me that the 4.08 was rare after '74, but then I don't see many west coast cars here.

Steve


[/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=4 width="100%" border=0><TBODY><TR><TD vAlign=top align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial] [/FONT]</TD><TD vAlign=top noWrap align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]

[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mike Mittelstead <NOSCRIPT> Mike Mittelstead </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 135px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Oh well, so much for those theories

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 8 2000, 8:57 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 135px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Thanks for the data points. From those, the cat/non-cat theory appears invalid.

My '76 cat car with 4.08s also has factory AC, so AC may be the determining factor.

I pulled a '74 trans out of a boneyard car, expecting a 4.08, but got a 4.42. Really doesn't mean a thing, with unknown history.

I'll let you get back to the important stuff now.
ThanX again! MM

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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mac <NOSCRIPT> Mac </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 15px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Inspection complete: discoveries, parts list & failure theory...

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 11:49 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 15px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]

Okay, I have completed the gearset inspection leg of the journey, and have revised the previous parts list to include my findings:

1 shifter tunnel boot

1 complete slave cylinder (comes w/ its boot?)

1 unobtanium slave cyl. hose

1 complete '83 5-speed gasket/seal set

1 lower lay-shaft bearing (complete)

1 new 2nd gear (ugh - I knew it!!)

1 new 1st/2nd synchro slider sleeve

1 new 5th gear synchro ring - optional

Now, let's follow back over Steve's instructions and I will chime in with my findings along the way...

For evaluation we will start with 5th and work our way down. 5th, 4th and 3rd all use the same "Porsche" type synchros, so the same proceedure will work on all of them. On the gear itself you will find two sets of teeth. The broad flat teeth that contact the corresponding gear on the driven shaft should have little or no wear.

These teeth are in great shape on all of the "Porsche type" gears. Look like new...

Next, examine the smaller teeth that engage the slider. These are on the edge or side of the gear and should have been cut to a point. They engage the sliding sleeve and are the ones that affect shifting.

These teeth all are beautiful as well. 5th and 4th look as good as new in every respect. 3rd does show a slight bit of wear - as a rounding of the machined top corner points - on these engagement teeth, but by comparison to the others, I am confident that 3rd is still well within the range of "good".

Now examine the sliding sleeves. Note that 5th has its own sleeve (with teeth on only one side). Test fit the slider to a gear to note how the teeth mesh. Examine the teeth on the side for the same points as on the gear. Typically you will see the most wear on the side of the slider that faces 3rd. Again the wear appears as a rounding of the teeth. [snip] The final item for the gear and slider is the slider's inner teeth. You will notice the slider's teeth are on the inside of the sleeve. These teeth have a broad, flat face.

All is well here. The 4th-3rd synchro slider sleeve does show a similar rounding of the engagement teeth on the side facing 3rd, but again, it is a very mild degree of wear. These parts are all good so far!

To check the slider, re-install a synchro on 3rd gear, with its locks and snap ring. Then test fit each side of the slider to the gear. The flat inner face of the teeth should contact the surface of the synchro ring before the engagement teeth have any overlap. This is how the synchro spins up before the teeth mesh.

I followed this procedure and was pleased to see that all components are working great - the synchro action is good & strong on all the "porsche" gears...

Finally, examine the synchro rings themselves. As noted earlier, it is normal to see some wear, as polishing, at the gap. Compare each gears synchro with the others. The further around the ring the polishing goes, the more wear.

This one came out with a suprise result! I examined the rings. Considering that all 5th and 4th components look like new, and 3rd looks close but slightly worn, I was expecting the same would be true of the synchro rings. Wrong! The 3rd and 4th rings look like brand new parts, but it is the 5th gear ring that is showing a suprising amount of wear! I was suprised...

Then again, driving all over the Northwest, up & down I-5 between Seattle & Portland, I suppose it makes sense, as I easily spend more time in 5th than in any other gear. 5th ring shows polishing at the gap as Steve described, and I did measure it to see if it was too far gone. The polish extends about 1/4 inch out from gap, then gets dull and extends slightly further before there is no marks at all. By the description he gave, it sounds like this ring could probably still have life left in it - I could probably re-use it, but since I already have the whole thing apart, now would be a convenient time to replace it. I haven't decided yet but I probably will get a new one.

The synchros for 1st and 2nd are "ring" type (also known as 'hub' type). First examine the main gear teeth as you did on the others.

They all look like brand new...

Then examine the smaller engagement teeth. Again, these should have neatly machine points. Some rounding is normal. Completely rounded is not and may require the gear be replaced.

I think I have found the problem!! The engagement teeth on 2nd are pretty badly chewed up, and so are the matching teeth on the synchro slider sleeve. They're pretty obviously rounded off. I tried fitting the pieces together for comparison. The 1st gear & its side of the sleeve are showing mild wear but are still in very good condition. When I fit them together there is no hesitation for them to mate, even if misaligned they just slot right together like they should. I tried the same thing with 2nd & its side of the sleeve, and they will go together quite nicely IF aligned dead-on, but if in any other position, the teeth just land on top of each other and sit there! CRUNCH!!

Note that beside the engagement teeth is a tapered hub with half a dozen narrow ribs on it. This is the synchro hub. Test fit the gear's synchro to its hub. Using modest pressure, fit the ring over the hub while turning the ring. The synchro should grip the hub before bottoming out. If the synchro bottoms out and you can still turn it, try the same test with the other synchro. If it too bottoms out, try the same test with both synchros on the other gear. What we are trying to determine with this test is whether it is the synchro or the hub that is worn out. If you have a synchro that bottoms out on both hubs, and one that doesn't, then you have a worn out synchro. If you have both sychros that bottom out on one hub and not the other, then you have a worn out hub.

Both synchro rings fit the 1st gear hub and don't bottom out at all - but both rings bottom out effortlessly on 2nd gear hub...

I typically like to see a measurment of about 50/1000 clearance before the ring bottoms out on the hub. 30/1000 or less and I would replace the synchro.

I don't have a micrometer, but by eyeballing the gap while using the 1st gear hub, both rings leave a gap that looks to be between 2 & 3 mm. Also, the inside face of both rings look smooth and clean but not polished. By this I assume that the rings are good?

Now we turn out attention to the 1st/2nd slider. The engagement teeth are on the interior of the slider. As before we are looking for fresh points on the teeth. And, as before, some rounding is normal. If the teeth's ends are beat up and completely rounded, the slider (like the gears) should be replaced.

As I mentioned upstream, the 2nd side is toast, so that made for an easy determination here! The sleeve needs to be replaced.

The 1st/2nd slider has teeth on the outside of the sleeve as well. This is reverse. On the 5 spd, the edge of the teeth next to the fork's groove is what is important, (on the 4 spd it is the edge away from the fork's groove). This is the side of the teeth that engage with the reverse idler. These teeth are cut with a slight taper at the edge. If they are uniform, without much rounding, the slider is usable.

They look fine here, but in my case it is a moot point since the slider sleeve is shot elsewhere.

Now examine the 1st/2nd slider's hub components.

Looks like new. No problems here that I can detect.

Finally, check the reverse idler.

Again, it shows a very mild taper on the side that engages, but so minimal that it is still basically like new.

Note: I have seen reverse in these transmissions in terrible shape. I have seen the teeth on the idler, the outside of the slider and on the driven shaft, worn almost completely off. Sometimes as much as 3/4th of the teeth gone.

Wow! Well, then mine really is like new!

Mac, you noted the bearing race on the end of the lay shaft was hashed. What does it look like?

It has a dull and pitted surface...

If it has a dull or pitted surface, it is.

You will need to check the rollers in the bearing itself too. It may need to be replaced as well.

There appears to be no significant damage on the rollers. Is it possible that this was just a defective race? In any case (no pun) since I have the case open, would it not be an opportune time to just replace the entire bearing anyway?

Usually you can heat the race with a lighter or small torch and pull it off with a pair of pliers. Or use a high quality chisle and carefully drive it off.

I happened to be running my propane shop heater at the time, so I just held the bearing end of the shaft up to the heater for a couple of seconds, and the little bugger came right off

Sooo, with all these new findings in-mind, it leaves me a bit puzzled as to why the 2nd gear failure became apparent as an immediate failure, and not as something wearing out and getting worse over time...

By the look of the pieces I have found to be damaged, it suggests that the 2nd gear hub wore out over time, and that I should have seen this setting in gradually - but that is not how it happened. I was driving along, all was well, and quite suddenly on a shift to 2nd I got a horrifying CrUnCh and it has crunched on every moving transition to 2nd ever since. Weird, and as a result I was expecting to find something fractured or literally broken, where instead all I have found is what appears to be a hub that is worn out over time, and ground-down engagement teeth which are probably a direct result of the hub being gone.

The only theory I can come up with that makes any sense is that, while most of the parts in this tranny were obviously new when I purchased it, the 2nd gear itself has to have been a used part!! Damn, it is the only way I can think of that this could happen. I can't imagine the 2nd hub wearing completely out in just one year.

Even assuming that this much of my theory is true, it still does not explain the immediateness of the failure. One minute everything was fine, the very next minute 2nd gear will not mesh and never has again.

I can only theorize that the 2nd hub was in fact used to begin with, and wore the rest of the way out over the last year, but that (because I always shift the 5-speed with respect and great care) that I simply had no indications or symptoms to make me think it was worn (ie: no little 'grunt' when shifting to 2nd). Then, on this fateful day when I was driving down a very bumpy gravel road, I just missed my clean shift to second, and in that one moment the fact that the hub was gone allowed me to smash the engagement teeth on that one missed shift, demolishing them - thus I could never get a clean 2nd shift again after that moment.

This is the only failure analysis theory I can think of that makes sense. Comments?? -Mac.



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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 30px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Great Job!

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 7 2000, 8:52 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 30px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Mac,

I agree with your findings. Replace the questionable 5th gear synchro. When we do "re-assembly" I'll give you some tricks on these.

The 2nd gear hub and slider are obviously the problem we were looking for. When I first guessed at your problem I didn't know the tranny had been apart before (big red flag). I now know EXACTLY what happened and why. The transmission had a bad 2nd gear synchro hub to begin with. This is quite common on early 5 spds. For some reason, on some early 5 spds the synchro hubs on the gears wear instead of the synchro itself. Don't know why this happens, I just know it does. I can't tell you how many 5 spds I have had people bring me that they had paid someone to put new synchros in only to have them die in a couple of months. Who ever did the work didn't check the hub, only assumed the synchro was bad and replaced (a perfectly good synchro) it leaving the bad gear and hub in it.

In this instance, the hub was already shot and the engagement teeth already had quite a bit of wear on them. The builder probably put in a new synchro on the old hub which gave it a little more life, until the new synchro wore the hub down the rest of the way and bottomed out. At this point, the synchro is bearly getting the job done and about this time, Mac makes a big grab for 2nd, the synchro can't respond, so what was left of the 2nd gear engagement teeth is lost.

Normally, what happens when a hub goes bad is; it behaves exactly like a synchro going away. That is; it begins as a lite grind on engagement and gradually gets worse over time, until all synchro action is lost. In this case, installing a new synchro changed the sequence slightly.

I have found this synario to be quite common since many of these bad hubs had new synchros fitted, which worked, temporarily.

A parts note: I think all 5 spd 2nd gears are the same so it shouldn't be hard to ensure you get the correct gear. But, to be safe, count the teeth and give them the number when you order it. Also, the snychro on 5th is the same as a standard 4 spd 3rd/4th synchro.

Nice job Mac.

Next installment: preparing the case.

Steve


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Mac <NOSCRIPT> Mac </NOSCRIPT>[/FONT]
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[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 8 2000, 7:53 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 45px">
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Steve Hoelscher wrote:
The 2nd gear hub and slider are obviously the problem we were looking for.

Yup. Knew it the minute I looked at 'em

But on the bright side, the fault was easy to find!

When I first guessed at your problem I didn't know the tranny had been apart before (big red flag).

Yes, I recall that I didn't mention that. Not deliberately, It's just that it was not a red flag to me at the time, because I was standing right there looking at all the parts with my own eyes. No, I'm afraid the only red flag is really that I was not as thorough in my examination of the thing as I should have been

The transmission had a bad 2nd gear synchro hub to begin with.

Most likely. I must make a confession here, I did not look at the synchro hubs when I bought it. Mac you dumbass

The synchro hubs on the gears wear instead of the synchro itself. Don't know why this happens, I just know it does. I can't tell you how many 5 spds I have had people bring me that they had paid someone to put new synchros in only to have them die in a couple of months. Who ever did the work didn't check the hub, only assumed the synchro was bad and replaced (a perfectly good synchro) it leaving the bad gear and hub in it.

Actually, since I am privy to the advantage of knowing where I bought it, and who I bought it from, and having been present at the transaction, I am going to go out on a limb here with that and pose a different theory based on this personal knowledge:

I did not check the hub out that day and it was my own fault because I did not fully understand the hub's role (meaning, I didn't know the hub itself could wear out, I just thought the rings wore). Thus, I checked the rings out, and the gears, and that damn stupid pinion-end bearing, and a lot of other bits. All of it looked to my eye as new...

In this instance, the hub was already shot and the engagement teeth already had quite a bit of wear on them.

I'll buy that the hub may already have been shot, but I saw those teeth that day and they did not look anything remotely like they do now. I mean, I was definitely no expert at judging these things, but I did visually compare the teeth to teeth on the other gears (not as closely as I have done this time with your guidance, but I did look pretty closely) and they all looked new enough that I could not see a difference then.

The builder probably put in a new synchro on the old hub which gave it a little more life, until the new synchro wore the hub down the rest of the way and bottomed out. At this point, the synchro is barely getting the job done and about this time, Mac makes a big grab for 2nd, the synchro can't respond, so what was left of the 2nd gear engagement teeth is lost.

I agree with it all, except that the gear's teeth, both sets, looked great to me that day in comparison to the rest of the gears, which still look great now.

I can only theorize, but I have a tendency to believe the seller's statement that the thing was full of new parts, A: because of who the seller was, B: because I looked myself prior to purchase and although I did not see the hub, everything I did see looked great, C: I have a hard time believeing this specific person would have deliberately tried to rip me off, and D: All the other stuff that looked good then still looks good (more or less)...

By the way though, I think the 5th gear ring was in fact a used one the day I bought the tranny. I seem to vaguely recall that we could not move forward with assembling it because something was missing (no it wasn't the 2nd gear you guys!) - I think I may actually have even told him to go ahead & use that ring, although it did not look so bad then as it now does.

Beyond all speculation though to me is that pinion-end layshaft bearing race!! I can't explain that to myself no matter what. Defective?? Odd part is that the bearing itself still looks good. It is only the inner race that is poop

I think the guy I bought this from probably had this tranny forever, several years at least, and at some point snagged the good 2nd gear out of the thing long before I came along - probably used it to fix some other X tranny eons ago. That leaves this thing minus 2nd. So he grabs up a different 2nd somewhere, which happens to have this bum hub, I don't know wether he knew it was a bum hub or not. However, knowing him as I do I find it difficult to think that he knew and was just going to 'wing it'. That does not seem his style. He is the type who would have just said, "hey this one's bad, we need a good one."

So I can't say what happened there, but apparently he at some later point comes back to the incomplete tranny, throws a used 2nd in there, throws a new synchro on it and puts it in the tranny in place of the gear that got previously scavenged out.

TIME PASSES

Then I come along and buy the tranny one day, and did not look at that damn hub.

Well, it is all quite ponderous to me right now. I do agree with you Steve about everything except that the 2nd teeth were not worn enough for me to see when I bought this (although, like I said, I am doing a much closer look now) and just to add the general caveat that I have a hard time swallowing that this was done deliberately to rip me off. Had to be a mistake.

At any rate, I will mention it next time I see the guy. See what happens. Peace, -Mac.



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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]<SCRIPT language=Javascript>  </SCRIPT>Steve Hoelscher <NOSCRIPT> Steve Hoelscher </NOSCRIPT>[/FONT]
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[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 8 2000, 10:15 PM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 60px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Then assuming the teeth on 2nd and the 1/2 slider were good. Then as the hub was dying, the teeth on 2nd and the 1/2 slider were taking a hit on every shift. The day 2nd died completely, that one bad shift finished it off.

Don't worry about knowing to check the hubs. Very few people know about that problem. It has been missed by plenty of good technicians.

Steve


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[/FONT]</TD></TR></TBODY></TABLE></TD></TR><TR><TD vAlign=top noWrap width="17.9%">[FONT=Trebuchet MS, Verdana, Tahoma, Arial]Mac[/FONT]
[FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD style="PADDING-LEFT: 75px" vAlign=top><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD align=left>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]plenty of good technicians...

[/FONT][FONT=Trebuchet MS, Verdana, Tahoma, Arial][/FONT]</TD><TD vAlign=top align=right>[FONT=Trebuchet MS, Verdana, Tahoma, Arial]February 9 2000, 9:09 AM [/FONT]</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=1 width="100%" border=0><TBODY><TR><TD style="PADDING-LEFT: 75px">
[FONT=Trebuchet MS, Verdana, Tahoma, Arial]...and me!!

Thanks again Steve for all of your input throughout this series of threads. I can't tell you how appreciative I am of the wisdom you (and everyone) are sharing with me here.

I may never really know how this all has happened or why. I can only speculate, as I said.

I suppose I could be really pissed off at the seller about this whole bum 2nd gear thing... but A: that would not help my situation any, and B: even when I thought I was buying a tranny with all new parts, I still only paid about $700 for it all-inclusive, which was an absolute steal - now I have examined all of these parts the right way, and see that it was in fact not what it was claimed to be to me, but most else still does look like new... so instead of getting a new tranny for a steal, I got a mostly new tranny for closer to average price.

I guess in the final analysis I can't be too pissed. Still wish I had seen that hub though. Well, we live & learn! At least I have this website to turn to, thank you all for that!

-Mac.



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Tranny Project: Inspection and evaluation

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