[FC] Diff Adjustment Confusion

[James Davis]

Well it is my opinion you can't set it up without a good inch pound torque 
wrench.  I use a Starrett 0-60 inch pound dial gauge one. For a standard 
trans diff, I use an old output shaft from a 4-sp with a 1/2 1/4 drive 
socket welded to the shaft.  For a PG, I wedge a 7/16 socket into the 
pinion shaft.  I find it best to set the side bearing preload without the 
pinion shaft and "O" rings installed, then mark the position of the side 
adjusters. I use and old yoke with a socket welded to it to set it 
up.   Install the pinion and set the pinion preload as listed. You read the 
total preload (side bearing plus the pinion preload.   Lastly set the 
backlash checking the pattern.  New gears will setup with about 0.005 
backlash and used about 0.009.  I think you will find the total preload and 
friction will be in the 30 inch pounds (14 bearing,  7 inlbs side bearing 
friction, and 9 side bearing preload).  Believe me that feels really tight 
especially with new bearings.  But then I have spun four pinions on the 
shafts in 40 years of fixing Corvairs, so I am very careful.  I now use 
welded pinions on all FC's and Ultra Vans.
Jim Davis



At 07:40 PM 3/14/2004, * Greenbrier Goon * wrote:
>Hey everybody:
>
>I spent today assembling and adjusting the diff. I am going to use in my 4 
>speed conversion.
>
>I seem to have the backlash and contact pattern right, but I am confused 
>about the "pinion turning torque."
>
>First of all, I don't have tool #J-8362 in my toolbox, so measuring the 
>torque might be difficult.
>
>As the diff. is now, it seems to spin very freely with very little 
>resistance.  Tightening the side adjusters to add some resistance results 
>in what seems like binding of the bearings.  I want to make sure I get 
>this right because I won't have time to do it a second time.
>
>Charles