[Fot] Fwd: Crown and pinion gear break in

[Michael Porter]

On 9/10/2018 3:41 PM, Bob Kramer via Fot wrote:
> I can't answer that but one could measure the dimension of the pinion 
> head and subtract it from the total shown to get the depth you would 
> want.
>
> Bob Kramer

I suspect that there are variations in parts due to manufacturing 
errors, tolerances stacking up, etc.  Most of the parts made at the time 
were not subject to the sort of scrutiny and computer-controlled 
measurements that are common today (although even that isn't a guarantee 
of uniformity--I had to redo a bunch of Toyota Supra IRS diffs in the 
early `80s because the computer that assembled them was misprogrammed 
and it swapped the shim stacks for the carrier bearings left to right).

That said, the safest way to get the diff repaired properly is attention 
to the shims when disassembling, and then putting the shims back in the 
same thicknesses and checking for the proper engagement pattern.  It 
does require some educated guesswork, and, often, disassembling and 
assembling a couple of times, but, if the pattern is right, the diff 
will be reliable.  I'd also recommend using hard shims in place of crush 
spacers on the pinion whenever possible if the pinion originally used 
those.  It also is a bit easier if one uses the case spreader 
judiciously on those housings requiring same, and doesn't crank it up 
too much.  Spread the case just enough to get the carrier and bearings 
out.  Figuring out the shim packs will be easier.


Cheers.

-- 


Michael Porter
Roswell, NM


Never let anyone drive you crazy when you know it's within walking distance....

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