The main areas to screw up on centre around fitting the mainshaft assembly into the casing and fitting the new mainshaft bearing. The bore in the casing for the mainshaft bearing is deep and a.tight fit.The bearing has to be drifted in past a circlip groove, and at this point it is easy to cock the bearing in the bore and if it isn't squared back up before drifting it home you can damage the bore to the extent that the bearing is a loose fit and may spin in service.Advice here is the heat up this area of the casing well, before attempting to fit the new bearing..Quote:
Originally Posted by djam1
Fitting the mainshaft assembly into the casing is very fiddly because the alloy bridge where the detent balls and interlocks fit prevents offering the complete assembly squarely up to the rear bearing.I grind some alloy from the underside of the bridge so that the straight cut gear(reverse) clears, then I just have to focus on winkling 1st gear, synchro ring, plus needle roller and thrust bearing set into position on the shaft whilst pushing the shaft through the rear bearing, whilst making sure that 1st/2nd selector collar(straight cut gear) and 3rd/ 4th selector collar don't slide on their hubs enough to allow the selector balls and springs to fly off into space never to be found again .Once the shaft is close to home it is also fiddly centreing the rearmost needle thrust bearing in position on the shaft because the shafts diameter steps down just behind the thrust bearings perch.If you dont get all 3 pieces of this thrust bearing in position you won't be able to fit the transfercase input gear, shim washer, circlip and distance sleeve.Once you do fit the mainshaft all the way home carefully fit these components immediately so as to avoid the thrust bearing washer dropping off its perch if the shaft slides forward inside the rear bearing.
Fitting up the input shaft and front gearbox bearing plate and bearing retainer can be a bit of a fiddle too if the new bearing is a tight fit on the input shaft.Most other points including selector shaft/fork fitment/ adjustment are covered by the factory manual. The diecast alloy oil pump coverplate should be resurfaced with a sheet of coarse wet and dry on a flat surface, as these warp and leak in service.Genuine transmission gaskets settle after awhile so allbolts/nuts should be retightened a half hour or so after intial assembly toavoidoil leaks.
Transfer case is reasonably straightforward, but I've seen silly things like the low range intermediate gear and centre difflock dog clutch fitted back to front.
A note on centre diffs. Std factory units tend to prematurely wear and develop excessive backlash.This is due to the hemisphere that the spider gears seat against not being machined concentric with the side gear registers, so that although it is a 4 pinion diff, the drive thrust loads are not distributed evenly over the 4 gears.Remanufactured centre diffs such as done by Jack Mcnamara Differentials or Total Traction in Moorabin in Vic are remachined true and concentric and last much longer. I have no affiliation with these firms.
Wagoo.
