<VV> Pinion turning torque

[VairMech@aol.com]

In a message dated 3/14/2004 11:53:15 PM Eastern Standard Time, 
NicolCS@aol.com writes:
I have never understood why GM was so scientific with the pinion preload when 
the side bearings are similar and operated in the same environment and 
"notches" were specified for their adjustment.  At any rate,  one and a half 
or two 
notches seems to work well for the pinion preload.
>>>>>>>>>>>>>>>>>>>
    I have taken many a diff apart with a loose pinion adjuster, no pre load. 
If you understand the forces that work inside the case, you to would be a 
little more careful on how you set up a diff.
    The pinion gear generates a LOT of fore and aft pressures and the case 
will expand and contract with the pressures. When the case expands then the 
preload changes. If you have to little pre load then the bearing on one end 
becomes loose and then goes back to where it was. With this process hapening 
repeatedly, then you wipe out a bearing and the diff usually goes with it.
    In setting the pinion pre load I have at times had to go a lot tighter 
than I thought to get the numbers that were called for. 
    The average # of notches will get you by most of the time, but it will 
bite you.
    Ken Hand