Calvin,

Just got the tranny apart on my OC-4. You do literally have to disassemble the whole rear end to get the tranny out. Don't remember the repair, but obviously the left final drive came loose sometime. the transmission housing has been welded and all the stud holes have heli-coils in them. So I guess I will be looking for a tranmission housing also. This one will do, but as long as I've got it apart, I'm going to replace it if I find another one. Reverse gear, reverse gear shaft and bushing are the only internal parts to be replaced. Left main drive shaft has has a couple of teeth welded an they have started to chip off,  so another shaft is in order. All the rollers are in good shape. The front wheels need new bearibgs and/or bushings. Will have them apart shortly. All four trunions need to be replaced. Track suspension units need replacement or refurbishing. The blade leveler cylinder will be refubished by a local shop who specializes in that sort of thing. Internally the motor is in very good shape. Very little wear on the bearings. Rings are in good shape so the oil fouling on the middle cylinder has to be coming from the valve guides. At any rate the engine was dropped off at a local engine builder this week. Right now the whole thing is pretty well down to the bare frame. Gonna cost a few bucks, but in the end I'll have a top condition bulldozer that will last me as long as I live.