question about installing differential, backlash

[ciffer]

I am working on installing a Detroit Truetrac in a Ford 8.8 axle (which I am told is very similar to 10bolt). I have the differential in and am working on getting the shiming right, the problem I am having is how to get an accurate backlash reading. When I move the differential back and forth the pinion will move slightly, throwing off my reading.

Anyone have any ideas?

 

[DEMON44]

it shouldn't move that easy. are you sure the pinion bearing is preloaded? that should carry enough rolling resistance, that you can rock the carrier pretty good without disturbing the pinion at all.

 

[ciffer]

I never touched the pinion, I am keeping the same gears, just changing the differential. It very easy to turn the differential. I know I am too tight at the moment, showing about .009-.010 with movement in the pinion, spec is for .008-.015. I'll change the shim and see what happens.