Got the LT 77 from my disco pulled down with suspected dud layshaft bearing (noisy in 1st, 2nd, 3rd....ok in 4th).

Apron stripping, found all bearings are quite good, but the rear cup on layshaft has fretted in the rear housing/plate and walked back a bit Taking preload off the tapered rollers. I'm guessing g it's missing somewhere around 0.040" of material.

I can probably clean up the cover in the mill, and either make a shim for u der the flange off the cup, or make a shim to go under the cone on layshaft, but the thickness would be just a educated guess.

Would I be ok dummy assembling the layshaft and mainshaft into the rear cover and check how gears mesh to try and gauge how much shim to add, or is there anywhere I mite be able to find the installed depth of the bearing cup anywhere? If I just clean up the bearing seat, the layshaft will obviously sit a bit further to the rear, which I don't think is the greatest idea.

At the moment, the cup actually sits proud of the rear face of the cover/plate......and I'm not convinced this is correct.

Rick