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How to track down a bad wheel bearing.


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Hey all,

 

My car has a distinct hum which I'm fairly certain is a bad wheel bearing. It's dependent on the rolling speed of the car, and is most noticable when slowly rolling to a stop. I had a couple friends ride with me and they insisted it was a wheel bearing too.

 

My problem... I have no idea which wheel bearing it is! Is there any way to find out what wheel bearing is bad... short of tearing the car apart (it's a '98 Legacy GT Wagon by the way). My two friends (who were in the backseat) said they heard it in the back, while I kind of thought it was up front. It could be multiple bearings, but I'd rather assume it was just one... and then fix another if it still turns out to be bad.

 

Also... the reason I'm motivated to research and fix this problem, is that my car has developed a nasty shake on the freeway. below 60mph, it feels fine. But once I get going faster than 60mph, my steering wheel shakes and wobbles really badly. I don't feel the car itself shaking at all, but the steering wheel is shaking quite a bit. Is this common with wheel bearings?

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from my experience with my accord i use to have they shouldnt make the car wobble at high speeds. it made a wah-wah sound when you were moving faster. do you know which side its coming from? if the bearing is bad enough sometimes you can jack up the car and turn the wheel or pull and push on it and you might get excessive play.. whic i guess could cause the car to wobble but sounds more like you have a unbalanced tire to me..

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Hey all,

 

My car has a distinct hum which I'm fairly certain is a bad wheel bearing. It's dependent on the rolling speed of the car, and is most noticable when slowly rolling to a stop. I had a couple friends ride with me and they insisted it was a wheel bearing too.

 

My problem... I have no idea which wheel bearing it is! Is there any way to find out what wheel bearing is bad... short of tearing the car apart (it's a '98 Legacy GT Wagon by the way).

 

Also... the reason I'm motivated to research and fix this problem, is that my car has developed a nasty shake on the freeway. below 60mph, it feels fine. But once I get going faster than 60mph, my steering wheel shakes and wobbles really badly. I don't feel the car itself shaking at all, but the steering wheel is shaking quite a bit. Is this common with wheel bearings?

 

The shaking indicates a likelyhood that it is a front wheel bearing. Do you have jackstands? if not you could do it with just the jack, but that takes a bit more time. . . Jack up each corner, like you were going to change a flat tire, get the tire off the ground and give yourself a bit of room to grab the tire from any direction. Putting a jackstand under the car at this point makes things a bit safer, but you need to try to move the tire from top to bottom (try to shake the tire, not in the direction that it normally turns, but from the top and bottom). if you get any movement top to bottom, you have a bad wheel berring, or a bad ball joint (if the balljoint is bad, only the bottom will be movable and not the top) If you can shake the top of the tire, you have found the bad berring. Keep going, there may be more than one. . .

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I'll try the tire-shake method tonight after work.

 

So you guys think the shaky wheel on the freeway might not be caused by a bad bearing? It's kinda recent (I just bought the car, and it felt fine the first couple weeks, then on the way home last night it started). Check for balanced tires maybe?

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If the sound is recent you may not have enough play in the bearing yet to feel any looseness. Have someone drive and you get in the back seat and stick your head back in the cargo area. You will likely be able to hear it better than from the drivers seat and you will also be able to tell which side it is coming from. If it's not really obvious in the back, it could be the front but you need to confirm it. You can put it up on a lift and listen with a stethoscope. Even then it may take some more wear to hear it.

 

I've had four rear bearings go out on my 90 legacy. Make sure they repack the new bearings before they install them. Mechanics seem to think they come from the factory already packed but it appears it's just a shipping grease and wears out within about 30 to 50 thousand miles.

 

As far as front end shake goes, check tire balance and go from there.

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Hey all,

 

My car has a distinct hum which I'm fairly certain is a bad wheel bearing. It's dependent on the rolling speed of the car, and is most noticable when slowly rolling to a stop. I had a couple friends ride with me and they insisted it was a wheel bearing too.

 

My problem... I have no idea which wheel bearing it is! Is there any way to find out what wheel bearing is bad... short of tearing the car apart (it's a '98 Legacy GT Wagon by the way). My two friends (who were in the backseat) said they heard it in the back, while I kind of thought it was up front. It could be multiple bearings, but I'd rather assume it was just one... and then fix another if it still turns out to be bad.

 

Also... the reason I'm motivated to research and fix this problem, is that my car has developed a nasty shake on the freeway. below 60mph, it feels fine. But once I get going faster than 60mph, my steering wheel shakes and wobbles really badly. I don't feel the car itself shaking at all, but the steering wheel is shaking quite a bit. Is this common with wheel bearings?

 

 

I thought I had a bad one in my 99 gt wagon. turned out the tires were cupped. When they were moved around the sound moved around too. Raising the tire pressure to max eased it some. the mechanic put it on a rack and put a stethascope on the axle but was not able to hear anything when the wheel was rotated.

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ditto on the cupped tires...I'm still on my winters because I CANT go through another summer with my cupped all seasons! I thought that it was my rear wheel bearings going out on me, but when I switched over to my winter tires the sound went away 1000000%. Do you have another set of tires to switch out with? The shake sounds like the tire is out of balance...did you loose a wheel weight?

 

The sound the all-seasons make drives me nuts :banghead: I really need to do something about them soon....Cooper Cobra GTH's by the way, I can't recommend them

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The way we tested is with a thermosat, it is digital and you jut point it at each bearing after driving down the road a few miles. The bad wheel bearing will show a higher temp. If the temp are all the same on each Wheel the it is likely to not be a bearing. of course we happen to have a Thermostat that is like point and shoot. You may not have one, see if ytou can borrow one. Good Luck, G

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I have a suspicious rumble, or maybe I'm just not used to the louder road noise of this car compared to other cars I've owned. I tried swerving gently left and right at about 50mph, it changes very little. It could be a bearing, a tire, or alignment. Since I'm new to the car, I'll just have to wait and see if it gets worse. I suspect it's normal for this car. You should try the gentle swerving, if it's noticeably worse in one direction, it's probably on the side you're putting the increased load on.

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An easy way is to jack up the front end with the car in neutral and the handbrake off. Put your hand on the spring in the strut and spin the tire by hand. You'll feel the vibration of a bad bearing in the spring long before you feel any wobble using the other methods. The same method can be used on the back wheels although there's more mass involved in the rear drivetrain. If you find a bad bearing in the front, do them both; if you don't, you'll be doing the other shortly anyway. Also check to be sure the castle nut is tight; it makes the same noise as a bad wheel bearing.

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May I add something to Gnumans plan:

If the wheel can move, get someone to apply the brake firmly. If the movement stops, then the bearing is worn. If a ball joint is worn, braking won't control the movement.

Put your hand on the spring in the strut and spin the tire by hand. You'll feel the vibration of a bad bearing in the spring long before you feel any wobble using the other methods.

 

Reading on this Board is like attending Car Repair University. You guys are realy clever. I learn new things every day. Thanks.

A lurker.

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Check the castle nut for tightness; not uncommon for them to loosen up and cause the rumble; quick and easy check to do.

I have a suspicious rumble, or maybe I'm just not used to the louder road noise of this car compared to other cars I've owned. I tried swerving gently left and right at about 50mph, it changes very little. It could be a bearing, a tire, or alignment. Since I'm new to the car, I'll just have to wait and see if it gets worse. I suspect it's normal for this car. You should try the gentle swerving, if it's noticeably worse in one direction, it's probably on the side you're putting the increased load on.
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Thanks :-)

 

Not to dis Edrach: Wouldn't it be prudent to lift the entire car...think AWD!

If you spin a front wheel and it turns a rear wheel, you either have a limited-slip front diff, or a bigger problem than we're talking about.

 

Thanks for the castle-nut tip, I'll have it up on jackstands for a look-under soon. Hopefully Haynes has procedures for torqueing that nut.

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I found this on the Timken site http://www.timken.com/industries/automotive/autoaftermarket/timkencatalog/PartCatalog.aspx, shouldn't there be an outer bearing assembly? This site has bearings for tranny, diffs, etc, in case you need to look them up.

 

Part TypeLocationTimken Part NumberQty Req.OptionFootnote

Bearing Assy inner517008 1

Seal inner1993 1

Seal outer225650 1

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If it's AWD yes it is; I was thinking of the 4WD cars when I did this since I went through this with my old GL wagon. Not sure how well this works with AWD since there's more mass involved with spinning the wheel.

Thanks :-)

 

Not to dis Edrach: Wouldn't it be prudent to lift the entire car...think AWD!

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