8n trans. mainshaft bearings

The cup (outer race) can be removed by welding a bead around the inside. The weld will shrink when it cools, race drops right out of the cap. If I remember right, you need to weld all the way around. I just tapped it on the welding table while holding it with the ground clamp. I'm no welder, probably did it with 1/8" 6011 or 6013 at ~80 amps.

There is a device called a bearing splitter that will clamp around the cone so you can get a push with your press or grab with your puller. Check out Harbor Freight for the economy model...

I think it was John Smith who mentions heating new cones in a toaster oven, ~350-400F, for awhile, and the inner race of the cone will expand enough to drop right onto the shaft. Search out his website.

The FO-4 manual will have some input on the preloading.

Tad

I have heard of some just dropping the cluster of gears on a piece of wood and letting the weight of the gears and Newton's law of motion remove the bearing.

The new bearing can be gently tapped back into place with the appropiate drift, large deep-well socket or hollow metal pipe (or press). HTH. Rick H. GA.