Reason for two different lengths of "dog bone?"

Yes, euro carb cars also got the longer bone.
Let‘s measure the length of the welded on bracket maybe?
Would be nice to get to the bottom of this.
 
Ah man, you going to force me to pull the snorkel off so I can remove the engine cover so I can measure the bracket! OK, I'm in.
 
IMG_3160.jpg


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On that crossmember bracket, I measure the distance from the bracket mounting flange to the bolt head at 21mm. My dogbone is about 147mm but I have no idea if that's the "correct" length for a fuel injected X (now dual IDFed).
 
Are we saying that the stand off of the bdogbone attachment bracket on the rear cross member is shorter on later models than earlier models, or that the rear cross member itself is farther back towards the trunk?

Good question !! The parts book shows that attachment bracket as not available as a separate piece - only as part of that crossmember. So...either that bracket is shorter.....or the piece it attaches to is now further back. I reckon we will only know the answer by measurements like Carl posted - from early and late X1/9s.....
 
Looks like that is going to be the answer. You can certainly see the diffrence in the brackets between Carl's picture and the early X in Rnafolh's posts. Now we just need the same measurement Carl did on an early braket. I'm betting the early measurement will be a good 10 mm (± several mm) longer from the cross member.
And now you have to wonder if the transitional 1500s had lower mounts more like the early cars. We have opened a can of worms here!
 
Can we put the worms back in the can because life used to be really simple, you had either an X with a stubby dog bone or a 128 with a longer dog bone.
 
Okay..in an attempt to clear all this up....or to further confuse....:oops:

The official parts books seem to show:
The dogbone for '73-'78 is Fiat # 4338203 which supercedes to 4437613
The dogbone for '79 up to 12/79 is 4437613
The dogbone for 12/79 on is 4468878 ( 12/79 would be halfway though the 1980 model year )
It is not clear to me which dogbone a 12/79 would take....

So it appears to me that there are 2 different dogbones....and is NOT a 1300 vs 1500 thing.

At the exact same time ( 12/79) that the change occurred....there was also a change in the upper chassis member that the dogbone bolted to. Which would lead me to surmise that....that mounting location is now further back away from the engine ! And thus required a longer dogbone to keep the top of the engine in the same location as before ( none of the other mounts or chassis bits changed at the same time )

The upper ( horizontal ) part of that chassis did not change at that time...only the lower ( vertical ) part of that member ( they are 2 separately available pressings ). Which would seem to mean that....either the vertical part of that member is now further back.....or more likely that the bracket that protrudes from it is now extended not as much.....

Our trusted faithful vendors seem to be at odds about all this.

Vendor "O" states that 4338203 and 4437613 are indeed the same and are 131mm long ( centre to centre ) and was used on all 1300s and 1500s up to 12/79. And that 4468878 is 153mm long and used from 1/80 on...

Vendor "E' states that all 1300s and 1500s up to 12/79 used a 134mm dogbone and from 12/79 on used a 147mm . And state the difference is due to that chassis bracket being "more extended" on the early models.

Vendor "V' states that all 1300s took a 137mm dogbone and all 1500s took a 148mm

Vendor "M" states all 1300s took the 4437613 132mm dogbone...and all 1500s took a 4468878 145mm dogbone

Quite a difference of opinions !!!! :oops:

I tend to believe the Fiat parts books and vendors O and E..

The controversy here seems to all about the early 1500 models. All the '79s and halfway into the '80 model year..

I reckon...a good approach would be to actually get some real life measurements for some 1500 models. To settle this once and for all..

I myself actually tend to believe that indeed there was a chassis change in 12/79. Most likely in the distance that bracket protruded from the vertical part of the upper chassis member.

Below is a pic of my late '81:

x19 81 chassis.jpg


You can see the bracket for the dogbone protruding out.

Under that top horizontal portion.....the vertical part of the member is recessed 1/2" from the front lip

The centre of the mounting hole for the dogbone is 13/16" out from the recessed vertical part. This seems to agree with Carl's ( '83) measured 21mm.

This mounting hole is about 1 3/4" lower than the lip above.

I'm betting that 13/16" measurement is considerably more on a '79 model. Now if we could only find someone with a '79 to measure and confirm. Larry...you are now up to bat........
 
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Yes, all this is got me wanting to drop everything and just go measure mine. But it is not handy right now. It's time to go get it and put it back in the slot now occupied by the other vintage vehicle. It is definitely a mid-year (1979) model. I can say that the ledge at the rear of the enigine compartent is the same, as are the engine lids and trunk lids obviously. So unless the cross meber tucks under the ledge on the rear a little more, the barcket must be longer.
 
. I can say that the ledge at the rear of the enigine compartent is the same, as are the engine lids and trunk lids obviously. So unless the cross meber tucks under the ledge on the rear a little more, the barcket must be longer.

I would agree with all that !!!!

As Larry cant make it to the plate....we need a pinch hitter......
 
Well, I went out and finally measured the bracket and related measurements on my 1979 1500. The magic number for the bracket is 34 mm as opposed to the 21 mm posted for later models. So it looks like the bracket is just longer.
Dogbone_bracket_1979.png
 
I tried. Move to Virginia and I can probably eventually grind through your whole surplus.
Larry, you now need to do the same for the "other" version.
 
When I put an 1982 1500 5 speed into my 1974 1300 4 speed body, I had some dog bone length issues. The new engine/transmission was a rather tight fit so I needed to adjust the dog bones length. I simply added a sleeved threaded section to the dog bone shaft, making it adjustable, and centered the engine in the engine bay. Worked great!
 
I put a 1979 1500 in my 1974 using the 1300 dog bone. It seemed to fit pretty much like it did for the 1300 motor.
 
I put an '82 1500 5speed into my '74 X. My dog bone didn't position the engine properly, so I cut it in half, threaded both parts, and put in a threaded stud with a locknut on both ends. Positioned the engine for the best clearance fore and aft and tightened the locknuts. Works great!
Dog bone 2.jpeg
 
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