79 CS2 differential pinion depth

[scherergroup]

Hi All, i am writing from Germany and ask for help for assembly my 79, CS2, 10/39 rear axle differential:
- as i don´t have the special Fiat tool to measure the pinion depth - can anyone tell me the nominal checking distance?

Definition: Position of pinion-gear relative to the ring-gear center-line, expressed as either a mounting distance (measured from behind the pinion head to the center-line of the ring gear) or a checking distance (measured from the face of the pinion head to the center-line of the ring gear)

thanks in advance
Wolfgang

[18Fiatsandcounting]

Hello Wolfgang. I don't have any measurements to give you, but I think the way this is done is to use yellow gear marking paste to determine where the pinion gears are riding on the crown (ring) gear. Prussian blue might also work. Basically, you put the marking compound on the gears, assemble them, and then check the wear pattern on the gear teeth. If needed, you adjust the pinion spacer to get the correct wear pattern.

That being said, I have limited experience with differentials, and with the few that I have taken apart, the pinion to ring gear spacing was already correct. I have also taken differentials to shops that specialized in rebuilding them, although that costs more of course.

Hope this helps.

-Bryan

[Nut124]

Brian is correct.

There is plenty of instruction out there, of varying quality:

https://www.yukongear.com/blogs/12-tech ... ly-setup_1