Date:         Tue, 2 Jun 2015 00:44:53 -0400
Reply-To:     Ed McLean <email99@BELLSOUTH.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Ed McLean <email99@BELLSOUTH.NET>
Subject:      Re: Rear axle torque specs?

I'm a bit confused by this thread.  Some one tell me if this is not a
correct description of the assembly.

IIRC, the Vanagon outer rear axle bearing is a straight roller bearing
and cannot be pre-loaded.  The axle nut simply clamps the inner race of
the inner ball bearing (which also cannot be pre-loaded), the
cylindrical spacer sleeve, the outer bearing inner race, and the hub
together on the stub axle as a single rotating assembly.  The required
369 lb-ft of torque is simply to insure these 5 pieces do not shift and
wear.  The cylindrical spacer specification insures the outer roller
bearing inner race is in the correct place in case of wear.  The spacer
is simply the softest metal part in the stack and will be the first to
wear if the nut is not torqued properly.  The stub axle rotating
assembly is kept from moving back and forth in the trailing arm housing
by the inner ball bearing whose outer race is held in the stationary
housing by a single snap ring.

Tapered roller bearings, like traditional front wheel bearings, can be
pre-loaded.  The outer roller bearing is not tapered and the rollers
will actually move back and forth on its inner race.  The inner bearing
is a ball bearing that also can't be pre-loaded.

Note in the ETKA parts blow up that the outer bearing (211 501 283 D,
#13) is called a "cylinder roller bearing", the inner bearing (211 501
287, #14) is called a "grooved ball bearing", and a "securing ring" (N
012 295 1, #15) is used to hold the inner bearing in the "housing for
rear wheel drive".



If heat is being generated in the rear axle bearing assembly then it
must be put together wrong or, as has been suggested, the spacer sleeve
is grossly worn out of specification.

It is also possible, as has been suggested, that heat from the brake
drum can cause over heating in the bearing area.  When I converted my
rear brakes to disks the caliper hung up on the pins and caused the
brakes to drag.  The excessive heat destroyed the grease seals and
caused the excessive grease I had filled the bearing cavity with to be
forced past the grease seals and soaked the brake pads and disks.  It
was a real mess.



Technique for Torquing Rear Axle Nut

The easiest way to properly torque the axle nut is to use a large socket
and breaker bar (3/4" preferred) and a 2' long cheater pipe.  Tighten
the nut by hand and then install the wheel and lower it to the ground.
Divide 369 lb-ft by your weight in pounds and then carefully stand on
the cheater pipe that many feet from the socket on the axle nut.  Do not
bounce but stand very gently and safely.  The nut will be torqued to
exactly 369 lb-ft.  You can also remove the nut with the same setup,
just pull upward on the cheater pipe and the nut will come off very
easily.

I hope this helps.
Ed