S series front wheel bearings

My wife has just emailed me about a noisy wheel bearing.

She reported whirring noise she described as persistent, related to acceleration, deceleration, but not when idling. I assume she means the noise continues at steady highway speed.but quiet when not in motion. I have taught her to listen to her car so I am sure the noise has only been audible for < 100 miles. She took it to a GM dealer, mechanic road tested and diagnosed bad wheel bearing.

My questions for the group.

How long will it take for the whirring wheel bearing to become complete failure in highway use?

Has anyone seen a Saturn S series wheel bearing turn in the hub or on the spindle? which I think would likely damage the hub or spindle? How bad (noisy) can they get before they damage other components? She needs to drive 100 miles to get home and I really want to avoid a field repair if possible. I would tell her to drive slowly and the car will be light and unloaded.

The manual recomends a special tool for bearing r&r but it looks like it could be done with a press and the usual collection of press and puller tools. I do have a welder if I need to do some custom tool making or modification. Comments from anyone who has done this repair?

Happy trails

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I can't comment about a Saturn, but I can say that on my previous car I drove with a bad wheel bearing for at least a couple thousand miles. It was annoying as hell, but nothing bad happened before I finally fixed the problem.

For what that's worth...

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oligoguy

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.

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