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Bearing Noise

Thought I'd share the following info I learned with regards to bearing noise. About 2 weeks ago my car developed a very slight noise which was nearly imperceptable but almost sounded as if a speedometer cable was going bad (no cable in my 1980 though). If I had to spell the sound it would be something like "schwit". It was sporadic and could only be heard at very low speeds of less than 10mph. Over the past two weeks the imperceptable noise turned into a full fledged rumble which increased and decreased with rolling speed but was very hard to isolate where it was coming from. Engine speed had no impact. I put the car up on jack stands and conducted an engine run bringing the drive train up to about 45mph and no noise whatsoever. For me that was a good thing meaning it wasn't transmission, CV, engine or rear wheel bearing related. Yesterday I put my son in the passenger seat and we spent about 15 minutes before he declared the noise to be coming from the right front wheel. A couple of good hard lane changes gave a change in pitch to help with the location diagnosis. I put the front end up on jacks, checked the wheels for play and found absolutely none! I then pulled the wheel and grease cap and there was plenty of grease. Next step was to disassemble the front hub. When I pulled the outer bearing here is what I first saw...



Some pitting and wear was evident but not too bad for a 26 year old bearing and certainly not enough damage to create the sound I was hearing. I scratched my head and was about to start putting things back together (save the bearing job for another day) and I took another good look at the outer bearing slowly rolling each roller and here is what I found



This was missed during the first look in which I simply held the inner portion of the bearing and spun the cage. This roller were not rolling and didn't show itself until I rotated each roller seperately.

I replaced the bearings and races and NO NOISE! Problem solved. Hope this helps someone out there.

Last edited by Motorhead-45; 09-10-2006 at 02:22 PM..
Old 09-10-2006, 11:33 AM
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Great post! There was just recently a thread where someone was asking about reusing some pretty old bearings because they looked and sounded good. This is an excellent wake up to go with your intuitions and replace what you think is bad. Good diagnostics and your son learned a very valuable lesson! I'll bet he's proud to have helped his dad!
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Old 09-10-2006, 11:40 AM
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A couple of additional things I learned from this experience. The race is not an easy one to get out. You can't just pound it out cold without the risk of damaging the hub! Heating the hub assembly for 30 minutes in the oven made it much easier to remove. Freezing the new race before install made it go in very easy. Your local Autozone, NAPA, etc. carries these bearings (inner and outer) under a TIMKEN part number for about $10.00 so reusing questionable bearings makes no sense. Autozone's loaner tool program includes a bearing race install driver kit which can be borrowed for only the cost of the fully refundable deposit. This will help insure you drive the new race in squarely.
Old 09-10-2006, 11:59 AM
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For next time.. and for readers..two things:

Those rollers in the first picture are very severely damaged..not at all what one would accept for normal wear..they are clearly unservicable.

Second..why even consider reusing old bearings anyway?

the labour of inspection makes it uneconomic..

Kind regards
David
Old 09-10-2006, 12:06 PM
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I would agree with davidppp. Looking at the first pic, I was thinking those are trash...The second pic made me think, ouch!
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Old 09-10-2006, 02:05 PM
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This thread brings up a couple of important issues ... sometimes misunderstood and ignored by many here:

1. Aluminum hubs and alternator housings should always be heated when removing and installing bearings! Exact temperature setting varies because of oven calibration, but 275F - 300F for 20 minutes will always work! Use a large brass drift or pin punch to knock the bearing or race out ... alternating sides or going around at 120 intervals. When installing the new bearing or race, heat the housing or hub, and freeze the new bearing or race for same 20 minutes ... after applying moly grease to the outer periphery and wrapping in Saran Wrap to prevent moisture encroachment.

2. Depending on your monitor and eyesight ... the first pic above may not look damaged! If the 'in person' examination shows any scratched, pitted, or grooved rollers, then the bearing should be replaced, without exeption! The matching races will usually show similar scratches, pits, or grooves, but appearance and lighting will affect your ability to detect the damage under shop conditions.
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Last edited by Early_S_Man; 09-10-2006 at 02:41 PM..
Old 09-10-2006, 02:38 PM
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Quote:
Originally posted by davidppp
Second..why even consider reusing old bearings anyway?
Kind regards
David
Because some owners are CHEAP.

Quote:
Originally posted by davidppp

the labour of inspection makes it uneconomic..

Kind regards
David

Because their time is worth nothing.
Old 09-10-2006, 02:48 PM
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Quote:
Originally posted by Early_S_Man
2. Depending on your monitor and eyesight ... the first pic above may not look damaged! If the 'in person' examination shows any scratched or grooved rollers, then the bearing should be replaced, without exeption! The matching races will usually show similar scratches or grooves, but appearance and lighting will affect your ability to detect the damage.
Good point...Let me throw an alibi in here and I believe this is the inverse of the point you were trying to get across....the bearing rollers in-person, and my eyesight is 20/20 "corrected", have no grooves nor scratches! They are very smooth with only a few pits with the exception of the bad roller in the second picture. I suspect what you guys are "seeing" in the photo are artifacts of a digital camera's flash and associated reflections from the counter top. Even the bearing cage "in-person" looks quite a bit different than the photo. The bearing race looked fine, no pitting, no heat distortion, no grooves and no scratches.

Last edited by Motorhead-45; 09-10-2006 at 03:46 PM..
Old 09-10-2006, 02:50 PM
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The main symptom of bad front wheel bearings for me was a wavering tach needle at some RPMs.
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Old 09-10-2006, 03:56 PM
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Well, that does bring another method to mind ... when you can't see any damage on a 'suspect' bearing! Fingertips and fingernails can often find pits, scratches, or grooves that aren't visible! If you feel an imperfection that causes drag or a snag on the fingernail ... time for a closer look, or trip to the bearing supply store!
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Old 09-10-2006, 04:21 PM
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I think the take away from this thread is that if the wheel bearings are suspect either by inspection or because of strange noises, replace them. It's not difficult if you use the heat and freeze technique described above and my total DIY cost for both sides was less than $50 for both inner and outers plus the two seals. This is one repair that doesn't suffer from the traditional Porsche tax.
Old 09-10-2006, 04:32 PM
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OK this is going to sound like I'm shilling for somebody but, over on kickstarter there is a group trying to get funding to bring an IPhone illumiscope / macrophotography attachment to market.
It would seem like a perfect application to use for this inspection. It even comes with a bore scope attachment. So I pledged $25, if they get their funding, I will get one of the first production runs.

I'm just saying...
Old 08-28-2013, 09:53 PM
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Quote:
Originally Posted by Motorhead-45 View Post
......... noise to be coming from the right front wheel.
Those noises are hard to locate, thanks for posting.
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Old 08-29-2013, 06:04 AM
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