I have a question that I havent found an answer for so far.
In the GM rears (95 tahoe, I believe its 7 5/8") what is the spec on play with
the spider gears? I seem to have a lot, at least I
think so. I think its causing a thumping when the rear goes over a bump, and the
drive line windup releases. Bumps taken under
accelleration are not as bad. Any thoughts guys? New spider gears? Worn splines?
To be honest, I don't think I've seen any specs on the spider
and side gear play. I do know that there must be, because you
used to be able to get different size shims that would go under
the side gears....this would decrease the backlash between the
side and pinion gears. Frankly, it's not usually that big of a
problem....and when it gets real bad, it's very obvious without
actually having to measure anything. Another area where you
can develop unwanted play, the bore of the carrier where the
side gears sit can get worn out...this can cause all sorts of wierd
things/noises to happen. And of course play between the
axles and side gears (where they are splined together) can cause
The big problem with rear ends is that there is actually
a fair amount of "stacking" that goes on when it comes to
end play. There are so many components inside the diff
carrier that each have a bit of play. When you add it all
up, it can cause quite a clunk. We get this complaint all
the time on new trucks. You can go between park and
drive and get a good size clunk/clink out of the rear end.
Totally normal....not much you can do about it unless you
want to get in there, tear it all apart and try to eliminate
the play between components. Which is a waste of time.
I swapped the Left and right rear tires. I had a newer tire on the right. This
seems to have helped with the thumping of the gears
going over bumps. Now the spider gears must be preloaded since the right rear
is a smaller tire and spins more revolutions than the
left in the same distance.
I'll have to look for new spider gears and shims. The next time the diff covers
off I'll replace them, seems easy enough.
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