<VV> Pinion preload

[VairMech@aol.com]

In a message dated 3/16/2004 2:15:00 AM Eastern Standard Time, 
dsjkling@sbcglobal.net writes:
The question is, how did GM do it?  The original differentials lasted a long
time so they must have done it right.  I would assume that is the proceedure
listed in the book. 
>>>>>>>>>>>>>>>
    The way the procedure in the shop manual works is this way, the pinion 
and carrier are installed. The pinion is then set to zero end play, no preload, 
then the carrier is set in position with the o-rings lubed and installed. Mark 
the pinion adjuster, snug it down so it will not move easily. Now go in and 
set the back lash with the side adjusters and set the pre load on the side 
bearings. Now loosen the pinion to where it was marked for zero end play. This is 
where you get the INITIAL turning torque, not the rolling turning torque. 
Record this number or remember it if you can. Now the book says to tighten the 
pinion adjuster to add to this remembered number. The number to add is 4-6 inch 
pounds with used bearings and 9-11 inch pounds with new bearings. So, you also 
have to remember if you put new bearings in! Anyway, lets say that the 
remembered number is 6 inch pounds that it took to start turning the assy with no 
pinion preload. Now you take that 6 and add 10 inch pounds for new bearings and 
you come up with a target of 16 inch pounds INITIAL turning torque, so you 
tighten the pinion adjuster until you get this number.
    NOW you go and check the gear pattern. If it is not correct then you need 
to start all over again.
    What I have found over the years is that the pinion gear and shim are 
matched. If you keep the same size shim and gear together you can put them on all 
different parts and the gear pattern will stay correct, usually.


Handy Car Care
Ken Hand
97 Peach
Pontiac, MI., 48342
248-613-8586
65 Corvair #22/42 E-Prod
WWW.CORVAIRMECHANIC.COM