GregS
ProjectX
Not driven yet. Is a track car and currently not registered. Apart from extra vibration I am not expecting to notice much difference in the driving, I did it mainly on Steve Hoelschers advice to protect the diff in fast launches.
Random Transmission Failures
- Thread starter Steve Hoelscher
- Start date
Steve Hoelscher
True Classic
This one is long but there is a story and background that, after doing a simple write-up and posting a few pictures, I thought was worth telling.
Just a couple of weeks ago I tore down a core that was returned by a customer. As usual, I won't name the individual but if they want to identify themselves they are welcome to.
This one is interesting on a couple of levels. Many of the units I build are units that were previously rebuilt and had some kind of issue and this one falls into that category. In this case the unit was rebuilt by and purchased from a reputable company. I will not identify that company for a simple reason. That company relied on an employee to do the work and that employee was responsible for his work. Certainly the business is ultimately responsible but I am sure that if the management had known about the deficiencies they would have taken corrective measures. I will give the company the benefit of the doubt. Sadly, that doesn't change the results I found.
This particular unit is an example of a nearly worst case scenario when making a major purchase on something that you cannot easily verify the quality of the product you are buying. Since you can't see inside the transmission or otherwise verify was parts were replaced, the quality of those parts and the skill of the technician, you have to take it on faith that you are getting what you are expecting. A reputable company is typically your best option in these cases. But nobody is perfect and that's what happened here. This is also why when I talk to somebody about rebuilding their X1/9 transmission and they tell me that they found a local shop that said they can do it cheaper, I cringe. Not because I think they'll be cheated, its because my experience is that even the most experienced and reputable shops struggle with these transmissions.
Now for the sake of honesty, I am the first to say nobody is perfect, and that specifically includes me. Nor is that fact likely to change any time soon. In fact, I shipped a unit this week that, as I was preparing to box it up Sunday, I had a nagging thought that I might have not installed the O-ring on the axle seal carrier. That seal carrier in on/off the case several times in the process of shimming the differential. During this process the o-ring is not fitted because it will interfere with the measurement. So did I remember to fit it on the final assembly? I can't be sure and I can't afford to assume and ship a unit that will ultimately have a massive oil leak. So, after removing the stub axle I was removing the four bolts that hold the seal carrier when I dropped one of the washers into the open hole and into the differential. Obviously, I can't leave the washer in the transmission so after failing at trying to fish it out with a magnet I ended up having to tear the unit back down to retrieve the washer. Oh, and in fact, I had left the O-ring off. I have on two other occasions pulled that seal carrier to check for the o-ring but this was the first time I found it missing.
So, on with the unit at hand. As was told to me by my customer, he purchased a rebuilt transmission from a US vendor several years ago. The unit worked initially then locked up. The vendor sent a replacement unit and that is the unit that was returned to me as a core. The customer's complaint was that 2nd gear was grinding badly and there was a substantial leak.
I tore the unit down and immediately found three significant problems. All three were a direct result of the choices made by the technician rebuilding the transmission. One of the things that will ruin a transmission is internal rust. We all have seen examples of cars that have been left sitting, or abandoned, for extended periods of time for whatever reason, until someone either decide to salvage the car for parts or restore it. We all know what happens when water gets into an engine. The cylinder walls rust and pit, rendering the bores unusable. In some cases the bores might clean up with a rebore or they can be sleeved. Transmissions are not so lucky. They tend to accumulate water from condensation. And a transmission, either in a car or not, left exposed to the elements, will accumulate enough condensation to rust the internal parts. Unfortunately, gears cannot be remachined if their mating surfaces have been pitted by rust and as a result, the bare mating surfaces are often ruined by rust resulting from condensation.
I don't know what happened to the first unit that the customer received that locked up but in the case of the second, the technician rebuilt a transmission that had considerable rust on the majority of its internals. When I opened up the case this is what I found:
The dark brown coloring on the faces of the gear teeth is rust. Deep, pitting rust. You can see it on both the input shaft (top) and the individual gears on the lay shaft (bottom). The gears, counting from right to left, are: 4th, 3rd, 2nd and 1st (which is out of the frame). It would appear that 1st gear had been replaced as it had no rust on the teeth.
2nd and 3rd on the lay shaft.
Above is the lay shaft 5th.
And this is the input shaft 5th.
Now you might question this: Why is this bad? The transmission worked. It had 12,000 miles on it. Well, if it didn't whine badly (and I am told that oddly, this one didn't), this is why its bad:
The brown coloration to the gear oil is rust residue that has settled out in the bottom of the transmission. That residue was eating the sychros and bearings alive. 2nd gear had long ago worn out, both the hub on the gear itself and the blocker ring. The bearing races are eaten up and I mic'ed the clearances of a few of the gears and sleeves and they are beyond spec. Although the gears were already bad due to rust.
So after evaluating the core: Only 1st gear is usable and it's sychro hub is marginal. The input shaft and gearset are ruined and all of the bearings are unusable. Even the pinion shaft gear is worn to the point I probably won't ever use it. So what's left. The case, a few miscellaneous parts that typically don't fail and the diff carrier. Except, it appears the case may not be good either. The customer noted it had a severe oil leak along the mating seam. This rebuild had used a paper gasket which can cause such a leak over time and why I rarely use them any more. But on inspection there may be a crack in the back case half which was likely caused when an unused portion of the case was broken off. That section if often broken off and I regularly use similar cases because it is so common. But it is necessary to thoroughly inspect the case for cracks there. They don't often crack from the break but its the most common place for a crack to occur. I have to thoroughly wash the case and use some dye to detect the crack. I'll probably do that this weekend.
I hate to find things like this. The customer didn't get what he had expected and the vendor probably didn't supply what they had thought they were. Not to mention the vendor had already had to replace one unit. And the customer had to pay to have two units installed instead of one. All because the technician didn't have the knowledge and skill to do the job correctly from the outset.
All of this to make a simple point. When you're shopping for something (whatever it is) cost does not always equal value. So spend your hard earned money wisely. I have learned this lesson myself more than once. And probably will again. But I try not to repeat mistakes when I can avoid it.
Just a couple of weeks ago I tore down a core that was returned by a customer. As usual, I won't name the individual but if they want to identify themselves they are welcome to.
This one is interesting on a couple of levels. Many of the units I build are units that were previously rebuilt and had some kind of issue and this one falls into that category. In this case the unit was rebuilt by and purchased from a reputable company. I will not identify that company for a simple reason. That company relied on an employee to do the work and that employee was responsible for his work. Certainly the business is ultimately responsible but I am sure that if the management had known about the deficiencies they would have taken corrective measures. I will give the company the benefit of the doubt. Sadly, that doesn't change the results I found.
This particular unit is an example of a nearly worst case scenario when making a major purchase on something that you cannot easily verify the quality of the product you are buying. Since you can't see inside the transmission or otherwise verify was parts were replaced, the quality of those parts and the skill of the technician, you have to take it on faith that you are getting what you are expecting. A reputable company is typically your best option in these cases. But nobody is perfect and that's what happened here. This is also why when I talk to somebody about rebuilding their X1/9 transmission and they tell me that they found a local shop that said they can do it cheaper, I cringe. Not because I think they'll be cheated, its because my experience is that even the most experienced and reputable shops struggle with these transmissions.
Now for the sake of honesty, I am the first to say nobody is perfect, and that specifically includes me. Nor is that fact likely to change any time soon. In fact, I shipped a unit this week that, as I was preparing to box it up Sunday, I had a nagging thought that I might have not installed the O-ring on the axle seal carrier. That seal carrier in on/off the case several times in the process of shimming the differential. During this process the o-ring is not fitted because it will interfere with the measurement. So did I remember to fit it on the final assembly? I can't be sure and I can't afford to assume and ship a unit that will ultimately have a massive oil leak. So, after removing the stub axle I was removing the four bolts that hold the seal carrier when I dropped one of the washers into the open hole and into the differential. Obviously, I can't leave the washer in the transmission so after failing at trying to fish it out with a magnet I ended up having to tear the unit back down to retrieve the washer. Oh, and in fact, I had left the O-ring off. I have on two other occasions pulled that seal carrier to check for the o-ring but this was the first time I found it missing.
So, on with the unit at hand. As was told to me by my customer, he purchased a rebuilt transmission from a US vendor several years ago. The unit worked initially then locked up. The vendor sent a replacement unit and that is the unit that was returned to me as a core. The customer's complaint was that 2nd gear was grinding badly and there was a substantial leak.
I tore the unit down and immediately found three significant problems. All three were a direct result of the choices made by the technician rebuilding the transmission. One of the things that will ruin a transmission is internal rust. We all have seen examples of cars that have been left sitting, or abandoned, for extended periods of time for whatever reason, until someone either decide to salvage the car for parts or restore it. We all know what happens when water gets into an engine. The cylinder walls rust and pit, rendering the bores unusable. In some cases the bores might clean up with a rebore or they can be sleeved. Transmissions are not so lucky. They tend to accumulate water from condensation. And a transmission, either in a car or not, left exposed to the elements, will accumulate enough condensation to rust the internal parts. Unfortunately, gears cannot be remachined if their mating surfaces have been pitted by rust and as a result, the bare mating surfaces are often ruined by rust resulting from condensation.
I don't know what happened to the first unit that the customer received that locked up but in the case of the second, the technician rebuilt a transmission that had considerable rust on the majority of its internals. When I opened up the case this is what I found:
The dark brown coloring on the faces of the gear teeth is rust. Deep, pitting rust. You can see it on both the input shaft (top) and the individual gears on the lay shaft (bottom). The gears, counting from right to left, are: 4th, 3rd, 2nd and 1st (which is out of the frame). It would appear that 1st gear had been replaced as it had no rust on the teeth.
2nd and 3rd on the lay shaft.
Above is the lay shaft 5th.
And this is the input shaft 5th.
Now you might question this: Why is this bad? The transmission worked. It had 12,000 miles on it. Well, if it didn't whine badly (and I am told that oddly, this one didn't), this is why its bad:
The brown coloration to the gear oil is rust residue that has settled out in the bottom of the transmission. That residue was eating the sychros and bearings alive. 2nd gear had long ago worn out, both the hub on the gear itself and the blocker ring. The bearing races are eaten up and I mic'ed the clearances of a few of the gears and sleeves and they are beyond spec. Although the gears were already bad due to rust.
So after evaluating the core: Only 1st gear is usable and it's sychro hub is marginal. The input shaft and gearset are ruined and all of the bearings are unusable. Even the pinion shaft gear is worn to the point I probably won't ever use it. So what's left. The case, a few miscellaneous parts that typically don't fail and the diff carrier. Except, it appears the case may not be good either. The customer noted it had a severe oil leak along the mating seam. This rebuild had used a paper gasket which can cause such a leak over time and why I rarely use them any more. But on inspection there may be a crack in the back case half which was likely caused when an unused portion of the case was broken off. That section if often broken off and I regularly use similar cases because it is so common. But it is necessary to thoroughly inspect the case for cracks there. They don't often crack from the break but its the most common place for a crack to occur. I have to thoroughly wash the case and use some dye to detect the crack. I'll probably do that this weekend.
I hate to find things like this. The customer didn't get what he had expected and the vendor probably didn't supply what they had thought they were. Not to mention the vendor had already had to replace one unit. And the customer had to pay to have two units installed instead of one. All because the technician didn't have the knowledge and skill to do the job correctly from the outset.
All of this to make a simple point. When you're shopping for something (whatever it is) cost does not always equal value. So spend your hard earned money wisely. I have learned this lesson myself more than once. And probably will again. But I try not to repeat mistakes when I can avoid it.
Steve Hoelscher
True Classic
I realized this morning I left out a key point in the above posting. The technician that did the original rebuild left out the magnet that sits in the slot by the Shift Rails. Of course that doesn't seem like a big deal. And because it doesn't have a direct mechanical function the tech wouldn't note it missing and the transmission would work normally. But all of that sediment in the bottom of the transmission contains the tiny metal particles worn away through normal use and the excess wear from the rust debris. And that accelerated the wear.
It is completely normal for a transmission, any transmission, to shed metal debris in operation. Especially when new, or when new parts have been fitted. Therefore its normal to find a layer of fine metal paste on the magnet. Its there to collect that debris and keep it out of the system. A filter of sorts. Leaving the magnet out allows that debris to circulate through the system, which increases wear, which increases debris.... and on and on.
That magnet is important and a considerable part of the mess in the bottom of the case is evidence of its absence.
It is completely normal for a transmission, any transmission, to shed metal debris in operation. Especially when new, or when new parts have been fitted. Therefore its normal to find a layer of fine metal paste on the magnet. Its there to collect that debris and keep it out of the system. A filter of sorts. Leaving the magnet out allows that debris to circulate through the system, which increases wear, which increases debris.... and on and on.
That magnet is important and a considerable part of the mess in the bottom of the case is evidence of its absence.
gene cooley
Autocrosser
I was careful to always speed shift my '72 128SL from 1st to 2nd at just over the 8000 mark. You could tell when it needed service by the "jingling" noise from the clutch/bellhousing area. This was the early warning that the springs in the clutch disc had collapsed and were about ready to break with the bits falling into the clutch jamming it so it wouldn't release. I usually found that after 2 clutch discs I might as well pull the trans apart and replace the bits in the gear cluster as they were broken and ready to come out or were already coming out.
Steve Hoelscher
True Classic
Ha! Yeah, these transmissions will time-out quickly in competition applications. When I was competing in my DSP X1/9, I would always freshen up the transmission a month or so before the National Championship. I would get about a season out of a transmission and figured going into Nationals with a fresh one was better planning that doing it after Nationals in the off-season.
Freshening it up was a 1-2 and 3-4 slider, 2nd and 3rd gear synchros and synchro locks and springs, plus the 1-2 and 3-4 shift forks. It got a new 2nd and 3rd gear every other season.
Freshening it up was a 1-2 and 3-4 slider, 2nd and 3rd gear synchros and synchro locks and springs, plus the 1-2 and 3-4 shift forks. It got a new 2nd and 3rd gear every other season.
gene cooley
Autocrosser
Hmmmm, guess I should have mentioned this was on the street. I was a lot younger then.
Might be part of the reason my 600 has a modified automatic...
Steve Hoelscher
True Classic
Back in my youth I drive my street car pretty hard too. From my senior year of highschool through college I drove a '77 1300 X1/9. It regularly saw the high side of 7K rpm.
I learned to rebuild transmissions from having to fix my 4 speeds after exploding the 3rd gear synchros. After multiple failures I finally learned enough to figure out why they were doing that and how to fix it.
Steve Hoelscher
True Classic
Maybe is just 2020 leaving its wake of carnage....
I have a transmission on my bench right now that I just finished over the weekend. This was a core that was returned earlier this year. I don't often know the history of the cores I get returned. In some cases they are just spare transmissions that the customer had accumulated at some point. Other times is the unit that came out of a car that was recently purchased and the new owner doesn't know the history. However, this one I am quite curious about. The unit had been recently rebuilt. I know it was recent because the reverse idler gear appeared new. As in, I just took it out of the package new. It had none of the typical wear even if well cared for so it couldn't have many miles on it. So a recent rebuild raises flags as to why its now on my bench as a core. There has to be some other issue. Most of the gearset is in reasonably good condition. It has an aftermarket 3-4 slider that, while in reasonable condition that particular style slider doesn't perform very well so I don't use them. The input shaft is OK. 1st and 2nd gear's synchro hub is tired but not dead. Whoever put it together used both RTV and a paper gasket set, and they used more than enough RTV. So much squeezed out of the case halves that it got in the 5th gear shift fork, the translator housing and a few other internals. No obvious failure, so why was it on my bench as a core?
I noted as I pulled it apart that it had generic 90wt in it. It didn't appear to be GL1 but it certainly wasn't MTL or any other synchromesh fluid, and it appeared to have been pretty fresh. When I was able to see into the bottom of the case this is what I found:
The yellow tint to the gear oil is normal 90wt. But there is a great deal of sediment in the bottom. Odd for a recent rebuild and fresh oil even if they changed the oil after running the unit some. So where did the sediment come from?
The last thing I look at when tearing down a core are the bearings. Mostly because the bearings for the input/lay shafts are not problematic and I have plenty in stock and diff bearings typically get replaced with new anyway. But this was unexpected:
pinion bearing race:
Diff bearing race:
Diff bearing:
Diff bearing.
to be sure... the rollers should be bright and shiny. The races too.
I inspected the input and lay shaft bearings with a loop just out of curiosity and the outer races are as bad as the above. They are so bad you can feel how rough they are just turning them with your fingers.
The transmission has six bearings in it and all were completely ruined. This transmission probably howled like crazy. Perhaps the reason for the 90 wt was to try and quiet down the noise.
So this was another case of somebody rebuilding the transmission, and actually doing a reasonable job. They did a fairly good job with the gearset and it probably shifted OK. But the reason for the rebuild was something came apart and chewed the bearings up and the rebuilder didn't know to inspect the bearings, or didn't know what he was looking at when he did and re-installed them. So all of that time/effort/money put into rebuilding this unit was lost.
I have a transmission on my bench right now that I just finished over the weekend. This was a core that was returned earlier this year. I don't often know the history of the cores I get returned. In some cases they are just spare transmissions that the customer had accumulated at some point. Other times is the unit that came out of a car that was recently purchased and the new owner doesn't know the history. However, this one I am quite curious about. The unit had been recently rebuilt. I know it was recent because the reverse idler gear appeared new. As in, I just took it out of the package new. It had none of the typical wear even if well cared for so it couldn't have many miles on it. So a recent rebuild raises flags as to why its now on my bench as a core. There has to be some other issue. Most of the gearset is in reasonably good condition. It has an aftermarket 3-4 slider that, while in reasonable condition that particular style slider doesn't perform very well so I don't use them. The input shaft is OK. 1st and 2nd gear's synchro hub is tired but not dead. Whoever put it together used both RTV and a paper gasket set, and they used more than enough RTV. So much squeezed out of the case halves that it got in the 5th gear shift fork, the translator housing and a few other internals. No obvious failure, so why was it on my bench as a core?
I noted as I pulled it apart that it had generic 90wt in it. It didn't appear to be GL1 but it certainly wasn't MTL or any other synchromesh fluid, and it appeared to have been pretty fresh. When I was able to see into the bottom of the case this is what I found:
The yellow tint to the gear oil is normal 90wt. But there is a great deal of sediment in the bottom. Odd for a recent rebuild and fresh oil even if they changed the oil after running the unit some. So where did the sediment come from?
The last thing I look at when tearing down a core are the bearings. Mostly because the bearings for the input/lay shafts are not problematic and I have plenty in stock and diff bearings typically get replaced with new anyway. But this was unexpected:
pinion bearing race:
Diff bearing race:
Diff bearing:
Diff bearing.
to be sure... the rollers should be bright and shiny. The races too.
I inspected the input and lay shaft bearings with a loop just out of curiosity and the outer races are as bad as the above. They are so bad you can feel how rough they are just turning them with your fingers.
The transmission has six bearings in it and all were completely ruined. This transmission probably howled like crazy. Perhaps the reason for the 90 wt was to try and quiet down the noise.
So this was another case of somebody rebuilding the transmission, and actually doing a reasonable job. They did a fairly good job with the gearset and it probably shifted OK. But the reason for the rebuild was something came apart and chewed the bearings up and the rebuilder didn't know to inspect the bearings, or didn't know what he was looking at when he did and re-installed them. So all of that time/effort/money put into rebuilding this unit was lost.
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Steve Hoelscher
True Classic
Another, core tear down from this past summer:
Another that falls into the categories of; Change your Gear Oil!!!, Use the CORRECT gear oil!! and; Be gentle with reverse.
I took a photo of the whole gearset as it came out, for amusement as much as anything else.
The gear teeth, on the outside of the 1-2 slider that have been chewed down from the left to past center, is reverse. The yellowish crud, on the far right, is the hypoid gear oil attacking the synchro's friction coating.
This is reverse on the input shaft. I was surprised it was this good. Which is to say its still not usable.
Reverse idler wasn't as bad as I though it would have been either.
But wait, there's more.
Change your gear oil. Most likely this car was not driven regularly and when it was it didn't get driven long enough to get the transmission up to full operating temperature. So it couldn't boil off the water that condenses out inside the case. That water gets circulated through the transmission and then rusts the places where there isn't much flow. Like inside the gear sleeves.
This is the pinion (lay) shaft. The whole shaft is red with rust residue.
As are the gear sleeves.
There was other, more normal carnage. Like the typical worn out 5th gear shift fork. This is so common I buy these in quantity. Nearly every build gets a new one.
Interestingly enough, earlier this week somebody posted in one of the Facebook X1/9 groups that they were rebuilding their 5 speed and wanted some tips. Somebody responded that they just did theirs and "it wasn't that hard". I wanted to reply but resisted. Hard is a relative term. I learned to rebuild transmissions rebuilding X1/9 4 speeds and later 5 speeds. Everything else since wasn't hard. In reality, its not hard to take an X 5 speed apart and put it back together, making it work right and live is a separate challenge. And its been my experience that even the taking apart and putting back together is beyond the ability of many.
Another that falls into the categories of; Change your Gear Oil!!!, Use the CORRECT gear oil!! and; Be gentle with reverse.
I took a photo of the whole gearset as it came out, for amusement as much as anything else.
The gear teeth, on the outside of the 1-2 slider that have been chewed down from the left to past center, is reverse. The yellowish crud, on the far right, is the hypoid gear oil attacking the synchro's friction coating.
This is reverse on the input shaft. I was surprised it was this good. Which is to say its still not usable.
Reverse idler wasn't as bad as I though it would have been either.
But wait, there's more.
Change your gear oil. Most likely this car was not driven regularly and when it was it didn't get driven long enough to get the transmission up to full operating temperature. So it couldn't boil off the water that condenses out inside the case. That water gets circulated through the transmission and then rusts the places where there isn't much flow. Like inside the gear sleeves.
This is the pinion (lay) shaft. The whole shaft is red with rust residue.
As are the gear sleeves.
There was other, more normal carnage. Like the typical worn out 5th gear shift fork. This is so common I buy these in quantity. Nearly every build gets a new one.
Interestingly enough, earlier this week somebody posted in one of the Facebook X1/9 groups that they were rebuilding their 5 speed and wanted some tips. Somebody responded that they just did theirs and "it wasn't that hard". I wanted to reply but resisted. Hard is a relative term. I learned to rebuild transmissions rebuilding X1/9 4 speeds and later 5 speeds. Everything else since wasn't hard. In reality, its not hard to take an X 5 speed apart and put it back together, making it work right and live is a separate challenge. And its been my experience that even the taking apart and putting back together is beyond the ability of many.
Steve Hoelscher
True Classic
Venting here.... not really at anybody but its frustrating. I need good cases and they are getting harder to find and now more than half the cores I get returned have bad cases. And again this week, I get another. This was an otherwise perfect case. It would have required a great deal of cleaning but it looked great on initial inspection. The first hurdle for a good case is getting the stub shafts out. As I have noted previously in this thread, if the stub shafts don't come out the case cannot be used because the case won't come apart with the stub shafts in. I use a slide hammer to pull the stubs and I have actually bought a big slide hammer specifically for this purpose but sometimes it isn't enough. I made a fixture for a make shift puller that would fit to the case itself and pull a stubborn shaft out but sometimes that isn't enough as I have previously documented here.
So the core I tore down this week I spent all day Sunday trying to get the right side stub shaft out of. I even made a new fixture/puller for the purpose. I was able to get it out but the stub shaft is ruined as it got bent slightly jacking it out. And I am always afraid that the case itself might have gotten damaged due to the amount of force it takes to get the stub shaft out. Given the need for cases I was willing to invest an entire day trying to save it but, from a business perspective, it cost me more per hour than it takes to buy a case from Matt.
The fixture I made to jack the stub out:
Once I got the stub shaft out I pulled the case apart and immediately noticed this unit had be previously rebuilt. I should have taken a photo of the end nuts on the shafts. Whoever rebuilt it _really_ didn't want those nuts backing off. They didn't just stake them to the shafts they hammered the collar until it was fully formed into the shaft's notch. Overkill to absurdity. I couldn't use a chisel to unstake them, I had to cut away much of the staking. What I couldn't got chewed off as they came loose. It took much hammering with the impact. In fact, my cordless wouldn't do it. I had to get out the Ingersol Air Impact. The nuts on the bench.
What I found when I got it open was the frustrating part. The gearset was a little tired but otherwise in reasonable condition but reverse was toast. Not unusual either. Note the amount of metal debris on the magnet.
That reverse is torn up wasn't the frustrating part, that case I spent an entire Sunday to carefully extract the stub shafts from, was bad. The previous rebuild was obviously, in a significant part, to a major reverse failure. The idler shaft was severely bent and that cracked the case in the idler shaft bore.
This is about as badly bent idler shaft as I have seen. And usually caused by trying to bump-start the car in reverse.
It also had a broken center detent spring. Its not uncommon for the broken spring to get picked up by the oil flowing through the diff and ingested into the gearset, with catastrophic results. This one got stuck behind the main shift rail where it was blocked from moving, fortunately.
So all of that work to try and save what I thought was a good case. I really hurts to have to throw what was otherwise a perfect case in the scrap pile.
Oh, and it occurs to me; given that the passenger side stub shaft was so hard to get out, no way the previous rebuilder had removed it. If so it would have some out this time easily. So they just let it go. So they couldn't have inspected the diff bearings on that side or changed the axle seal. In fact, neither of the axles seals hadn't been changed.
So the core I tore down this week I spent all day Sunday trying to get the right side stub shaft out of. I even made a new fixture/puller for the purpose. I was able to get it out but the stub shaft is ruined as it got bent slightly jacking it out. And I am always afraid that the case itself might have gotten damaged due to the amount of force it takes to get the stub shaft out. Given the need for cases I was willing to invest an entire day trying to save it but, from a business perspective, it cost me more per hour than it takes to buy a case from Matt.
The fixture I made to jack the stub out:
Once I got the stub shaft out I pulled the case apart and immediately noticed this unit had be previously rebuilt. I should have taken a photo of the end nuts on the shafts. Whoever rebuilt it _really_ didn't want those nuts backing off. They didn't just stake them to the shafts they hammered the collar until it was fully formed into the shaft's notch. Overkill to absurdity. I couldn't use a chisel to unstake them, I had to cut away much of the staking. What I couldn't got chewed off as they came loose. It took much hammering with the impact. In fact, my cordless wouldn't do it. I had to get out the Ingersol Air Impact. The nuts on the bench.
What I found when I got it open was the frustrating part. The gearset was a little tired but otherwise in reasonable condition but reverse was toast. Not unusual either. Note the amount of metal debris on the magnet.
That reverse is torn up wasn't the frustrating part, that case I spent an entire Sunday to carefully extract the stub shafts from, was bad. The previous rebuild was obviously, in a significant part, to a major reverse failure. The idler shaft was severely bent and that cracked the case in the idler shaft bore.
This is about as badly bent idler shaft as I have seen. And usually caused by trying to bump-start the car in reverse.
It also had a broken center detent spring. Its not uncommon for the broken spring to get picked up by the oil flowing through the diff and ingested into the gearset, with catastrophic results. This one got stuck behind the main shift rail where it was blocked from moving, fortunately.
So all of that work to try and save what I thought was a good case. I really hurts to have to throw what was otherwise a perfect case in the scrap pile.
Oh, and it occurs to me; given that the passenger side stub shaft was so hard to get out, no way the previous rebuilder had removed it. If so it would have some out this time easily. So they just let it go. So they couldn't have inspected the diff bearings on that side or changed the axle seal. In fact, neither of the axles seals hadn't been changed.
Attachments
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Steve Hoelscher
True Classic
Thank you Jim. I appreciate that and your patronage.
Steve Hoelscher
True Classic
I was originally going to shoot video of this teardown but I ended up putting so much time into getting the stub shafts out I was just wanting to get it over with. I'll try and setup a camera when I get ready to do yours.
If you can, tell me what you remember about it and we'll play guess the failures before teardown.
Rodger
True Classic
A little, but not much off topic. Steve, you did a rebuild on my ‘79 5 speed a couple of years ago, after my attempt came up short. Since I was involved in my ‘81 K20 build, I never did install it, and now the ‘79 is totally stripped down awaiting restoration. What is the best way to keep the transmission in good shape so I don’t end up getting rust inside? I never filled it with oil and have always kept it wrapped up in a heavy gauge plastic bag, sitting bell housing down which is how you shipped it. It has always been in my attached garage. The garage is not heated, but doesn’t get much below 50 degrees in the winter as it is part of the house. It will probably be another couple of years before it will get put to use. Thanks.
Bjorn Nilson
True Classic
Yes, please share a teardown video for us that are too far away to send the transmission to you. I have no experience in gearboxes and I am about to tear down my locked 5 speed and hopefully fix it. At the same time I will have a taller final from a Ritmo/Strada/Regata. With my lack of experience I watched several videos on YouTube but they are mostly covering Landrovers and Chevys.
I am really scared about this operation.
Steve Hoelscher
True Classic
Rodger,
Glad you asked. I do give all of the components a light coating of oil during assembly. That coating is intended for assembly and short term protection from condensation and oxidation. Long term storage is a different matter. Over time the oil drains to the lowest point and there is exposure to the ambient humidity.
Considering long term storage I would to the following: Put a quart of 20/50 motor oil in it, standard petroleum would be fine. Then rotate it from bellhousing down, to extension housing down, and back to upright. Then with it sitting in its normal upright position (not on the bellhousing), and in any gear, turn the two stub shafts through several rotations. This would ensure that oil gets circulated (and therefore coats) all of the components, including the differential and 5th gear (inside the extension housing). Then put it back in the plastic bag and let it sit in the upright position for storage.
Sitting upright will keep the oil from settling to the right side stub shaft seal and draining the 5th gear extension housing.
I would also repeat this procedure every six months. The idea is to keep oil on the gear surfaces and in the bearings and prevent condensation from settling on the exposed surfaces. If you can find some desiccant packages to put in the bag that would be great.
Rodger
True Classic
Thanks for the great advice. I happen to have a left over quart of 5W-40 synthetic taking up space on my shelf. Can I use that or should I get the 20W-50?
Steve Hoelscher
True Classic
5-40 is OK. I like the 20/50 because its the correct viscosity and will flow slower when cold.
Oh, and an important note. When you stand the transmission on the extension housing the oil will want to run out the vent. Remove the cap and stick something in the hole as a plug. Once you complete the process, remove the plug and refit the cap.
Jeff Stich
True Classic
Possible "freebie" if you pay for shipping? (not mine, but I can help)
https://xwebforums.com/forum/index.php?threads/struts-hubs-and-top-mounts-for-sale.39748/