Fly Navy

I've been trying to isolate the source of road noise on my 87 S4. Detectable at speeds in the 30-60 mph range. Not consistent, varies in pitch with speed and seems to be most prevalent on sweeping turns or when loading one side or the other - so I thought (hoped) it might be a wheel bearing vice something more severe. No noise at idle when stopped...no clicking noises on turns...nothing on reverse...

I've jacked up both sides and did the shake-test...both rears are rock solid, no play at all. However, the fronts both have just the slightest play when my hands are 12 and 6 O'clock - nothing when shaking from 9 and 3.

I'm not throwing grease - all the rubber boots are clean and pliable - no cracks. Car has 115K miles...

A VA-Beach Porsche garage previously quoted me $780 to replace rear-end bearings on both sides (haven't called back to see if front's are a different price).

Any help out there - is that a fair price for a bearing job or is this a DIY job?

Mike

Bill Ball

That price is fair. Although it can be a DIY job, you need a press with a bunch of bearing drivers (I used huge sockets), a heat gun or propane torch or oven, a 3/4 inch drive breaker bar and socket set, a 325 ft-lb torque wrench, and some luck with getting the parking brake springs back on without struggling. The front bearings are much easier and should be far cheaper.

You might try cleaning and repacking the front bearings and making sure they are snug. There should not be any 12-6 movement. The rear bearings are sealed and not adjustable.

I agree that noise on side loading points to bearings.

mark kibort

jack up the rear of the car and get it on stands and get the car in gear in 5th to 140mph or so. then, put it in neutral, get out of the car and listen to the wheels coast down. if they are howling, then one side or the other will be in need of a bearing. however, if they are quiet, it might be the front bearings. if you catch it early enough , you could just replace the bearings and not the races as i have up front over the years. (inners and outers)

by driving the car and listening, see if the noise increases on one turn direction vs the other. the loaded side making noise is the wheel that needs new bearings . they are cheap. re greasing them, will do nothing if they are bad.
and you cant tell by spinning the tire. it has to be going fast and under load.

mk

Landseer

I just did fronts.
With wheels off, turning by hand, I had definitive roughness in the right front.


If I had ever done rears I would drive to Williamsburg and help you DIY. If you decide to try it, and research it enough, let me know and I'll pile my press and wrenches in the pickup and come help.

But we still might need Bill Ball on the speaker phone. Or maybe Dr. Kibort. ( Mark, my dad watched your racing videos over and over too, just like he did with Mark A's.)

On another tack, I've got enough United miles to fly Bill here to direct this operation. Would do it just to meet him in person!

Is it bearings or back CV's?

Mrmerlin

if the front bearings are adjuster correctly and you have play in them check the lower surface of the inner bearing seat, and also the outer bearings seat where it is next to the threads on the spindle. It seems that the spindles wear out in the inner races this is a very frequent thing, I wonder if the heat treatment was incorrect for these parts

Bill Ball

If you've got the tools, you don't need me to guide you through the rear wheels bearings. The WSM has some basic information, and the rest is just being careful when you press in the new bearing into the carrier and then the hub into the bearing that you support the right parts of the bearing. You need to improvise support alternatives to the Porsche tools.

At this point he has loose front bearings, a much simpler situation. There's no indication yet he needs to replace the rears, or the fronts, for that matter. If I were doing this myself, I would buy a set of front bearing with races and seals, which is very inexpensive, then remove the fronts and examine them. If they look OK, repack them and reinstall and adjust, saving the new bearings for later. If worn, install the new bearings.

Jim bailey - 928 International

Book time for both sides rear wheel bearing is about 5 hours plus a couple hundred dollars in parts. It is acceptable to just do the side which is making noise.

Shark Attack

I know the bearing is pretty costly. I think his price is about right. If you want to save money remove the knuckles and take them to him. That will same him a lot of time and you also may see some thing that is not right that maybe he didnt pick up on

jon928se

Remeber that you can isolate bearing movement from suspension bushing wear/ tie rod wear by performing the 12-6/9-3 shake with an assistant applying the brakes. The brake pads clamped to the rotor prevent bearing looseness being felt.

928FIXER

did you try swapping tires to see if the noise changes??

Fly Navy

I just got a quote for the front end of just $380 (both sides parts and labor).

I think that's what I'll do given my limited mechanical skill and tool shed. Hoping their test drive doesn't indicate I've really got a differential or transmission issue instead!

Chris - your offer was incredibly generous. Next time you're in Williamsburg, give me a shout.

Mike

Bill Ball

Both fair estimates. Probably not a job to cut your teeth (or knuckles) on. Learn to do brake pads and other routine maintenance first.