Suspension & Steering
Wheel Bearings, Rear
Some on the list said that if there is any play in the rear wheel bearings that they must be replaced, as there is no provision for adjustment -
There is no provision for adjustment, but if there is any play, you certainly should try torquing the bearings to the proper figure, rather than replacing them.
This retorquing can be done by removing the center cap, putting the trans in reverse, and tightening the nut to 322 lb/ft. This will require a 3/4" drive torque wrench. Since this will take only five minutes, you probably can talk your 928 tech into doing it for free - if you have a very friendly working relationship!
First, if your problem is bearing noise, check that the axle nut is tight. The rear wheel bearings are two-row radial-thrust ball bearings, and if the nut is loose, you will get bearing noise. The torque on that puppy is 339 foot pounds! That is 80 pounds on a four foot handle!
This bearing replacement method worked for me - YMMV.
Put the new bearing (P/N 999.053.050.02) in the freezer. Loosen the axle nut. Remove the half shaft (axle).
Remove the caliper - don't take the hose off, just hang it on the suspension - don't hang it by the hose! Take the brake disk off. Remove the parking brakes, and pull the cable out. On ABS cars, remove the sensor. Remove the upright (hub carrier) by removing one top bolt & partially removing the large bottom bolt. The shock holds the spring - no compressor needed.
Clean everything very well. Drive the hub from the upright. This will destroy the wheel bearing. I had to cut the inner race off the hub with a die grinder - the book says to press it off. Don't scar the hub! Put the hub in the freezer. Remove the parking brake backing plate and the snap ring.
Put the upright in the oven at 300 degrees (per the shop manual) or at 200 degrees (worked for me). Carefully (very!) drive the bearing from the upright. Slip the (cold) new bearing in place. Make sure that it goes all the way in - mine just fell in, but I had really chilled the bearing by using dry ice and actone.
Reinstall the snap ring, and be sure (very!) to put the parking brake backing plate back on. The bearing should now be pretty warm from the upright heat, and the hub should be pretty cold. Be sure that you have the snap ring and the parking brake backing plate in place, and drive the hub in place, supporting the inner race as you do this.
Reinstall everything, being careful to get the parking brake retaining springs hooked over the edge of the holes.
Torque the axle nut to 339 ft/lbs. I removed the small center cover from my wheel, and torqued it with the wheel on the ground - having someone hold the brakes is probably required. I don't know whether the parking pawl in the transmission would stand that kind of load or not.
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