[suicideneil]

Nay, you have to replace both front and rear diffs, as the 1/8 scale diffs are a different ratio to stock diffs- you would have rear wheels trying to spin slower than the fronts if you only changed the rears.

8x16 bearings yeah, I remember now- funny as I wrote a tutorial on building UE diffs (old age = bad memory... 25 is old...).

The shims are the correct ones too, you should only need one or two on each pinion between the inner bearing and back of the pinion head to set the mesh.

Looks like the bearings on the diff might be the right size already as most 1/8 vehicles tend to use the same size items (9 times out of 10 anyway), but new bearings wont hurt regardless- cheap enough.

I dont believe you'll need anything else, just fill up the diffs with your favourite thickness of fluid (I use 7k and 4k, front and rear, rather generic setup) and that should be that.