Reply to "rear upright bearing"

quote:

Originally posted by Bosswrench:
Chris, there are currently two different methods used to run tapered roller bearings in the rear. Both require the uprights to be machined to a larger OD inboard, and method one then uses a modified spacer between the bearing halves. That setup uses stock 250+ ft-lbs of torque on the axle nut.

The other method uses NO spacer between bearings- like with front wheel bearings- and only 5-8 ft-lbs of torque on the stock axle nut. This lightly-tightened nut must be firmly locked either with red Lock-tite if you have faith in chemicals, or a mechanical locking device if not. Both require periodic greasing of the bearings, just like front wheel bearings. Ball bearings are sealed.

Both work but obviously the first method needs far greater precision in all parts of the assembly and will be more heat-sensitive due to metal heat expansion. As an experiment I converted ONE upright on our car in 1995 using method 2 with no spacer; a direct comparo between the two sides of our car over the years shows zero advantage with tapered rollers, except that stub-axles can be replaced without a press since tapered roller bearings are slip-fits instead of press-fits on the stub-axles. Note also that this conversion almost always uses billet-steel stub axles; a seizure on a stock axle will normally break it, also taking some of the rear bodywork with it.

In my opinion as a user, this conversion is not worth the risk, trouble or expense. If it gives you further trouble, you can go back to stock by using two stock outer ball bearings and a proper press-fit on the stub axles. I would also suggest if the system seized solid on you, to disassemble and inspect the rollers, and heavily grease NEW tapered roller bearings and their races. Even billet axles will break if abused.