This post to update previous request for experience re bad wheel bearing.
Once my wife got the car (96 SW1) home (no problems), I jacked up both
front wheels and was able to easily hear the side that had the problem. I
do not think much of the garage mechanics diagnosis skills that he did not
do this first. (or ever). I removed the brake caliper to isolate the noise.
With the wheel on, but the brake caliper and pads removed, the rough rolling
sound was quite clear but I still thought the sound may be coming from the
CV joints or transmission.
I drained the (5sp manual) trans fluid to have a look at it and to run a
magnet into the trans and through the fluid. I was unable to get a slim
magnet into the trans case as the drain takes a sharp corner just inside but
I was able to check the fluid in the pan before I poured it back into the
tranny.
I picked up a new bearing and then removed the steering knuckle and hub from
the car. The bearing did not feel that bad but did sound a little dry.
Haynes gives up at this point and says go to a pro with a press and special
tooling. Chilton gives 7 pictures of some tooling and pressing but could be
clearer as to how the assembly is disassembled. The hub must be removed by
pressing outward first, I used a socket to press on the hub inside the
bearing inner bore. The outer-inner race remains attached to the hub, I
removed it by heating it quickly with an oxy-acetylene torch which expanded
it enough that it almost fell off the hub and required only a couple of taps
to remove.
The bearing retaining ring is then removed and the bearing outer race
pressed out towards the inside. There is really nothing to press against to
remove the outer race so I removed the inner-inner race by driving it out
towards the inside. I then ran a bead with my electric welder around the
inside of the outer race and allowed it to cool and shrink. After it was
cool I tapped it out with a small punch and hammer, take care not to ding up
the bearing bore in the knuckle, this is a good job for a brass punch.
After cleaning every thing up and removing all rust from the bore I gave the
knuckle a careful visual inspection. The new bearing has a very thin outer
race and the bearing must be pressed below the surface of the knuckle. I
think the bearing would almost certainly be damaged by pressing on the inner
race so I went to a local machine shop and had them fab me a bearing driver
best described as a 1" thick washer with a 2.650 outside dia and with a 3/4"
hole. The center hole is optional but I always put them in any press
adapter to allow the use of a center bolt to use it as a puller tool as well
as a press tool. The adapter washer cost me $20 but I got the friend
discount and it could easily have been more. The adapter was just a little
smaller than the bearing bore.
I lightly oiled the bore and heated the knuckle slightly to expand the bore.
I pressed the bearing into the bore with a 20 ton press. The bearing did
not go in smoothly but in a series of small jumps as I continued to pump the
press slowly. I am sure these jumps would have damaged the bearing if I had
been pressing only on the inner race. Once the bearing was bottomed out in
the bore I installed the retainer ring in the bore.
I pressed the hub into the bearing using a socket to apply pressure only to
the inner bearing race. The bearing turned freely during and after the
pressing operation.
The hub and knuckle was reinstalled. It was immediately obvious that the
bad sounds had gone and the axle turned easily and quietly with the trans in
neutral.
This is not rocket science but I believe that the bearing driver plate is
absolutely essential and that shrinking the old outer race with a weld bead
is the only easy way to remove it. I do have a bearing splitter that
probably could have removed the inner race from the hub but with great
difficulty as there is not much of a lip under the race, removal using an
oxy-acet torch is easy. I would have cut the race off if necessary but it
only required expansion with heat. Do not overheat or cut into the hub.
The job took most of the day and required a little running around but the
garage quote was for $340. and I bet they did not have the correct tooling
and would have just pressed on the inner race which could cause a failure
soon after any (usually 20 minutes or 20 feet) warranty expired (payment
cashed).
This repair requires experience and tools most backyarders do not have, but
now that I have done it once and have the custom tooling it would be much
easier the second time. My first rule of mechanics is that no part you have
a spare for ever breaks, and you never need to do any job you have the
correct tools for, so if experience is any guide I will never have to do
this job again. That alone is worth the $20 price of the tool and $58 price
of a spare bearing (I think I can get a better bearing price in the city, it
is brg # SKF-311315-BD (A07) SKF box/stock # FW168)
I hope nobody needs this information and as always YMMV.
