What a bad wheel bearing sound like? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

sasha055 · 05-18-2010, 01:14 PM

Hi,

I have a bad wheel bearing I beleive...
I can hear a "whooo" sound from my rear left when I'm going over 50mph.

It's not very loud, with the top down I can't hear it (I can if I listen for it.) however with top up I can hear it clearly...
It quiet before 45-50mph... it gets louder when I go over 70..

Is it a bad bearing? how can I test it?
I would really like to be sure that it's a bad bearing before dropping 300$++ for SIR tools to replace it.

Any advice on what that sound could be?

Also is there anyone in Seattle area that have the tool and will be kind to let me borrow it? or sell me a used one?

Thanks
Sasha

boxster6354 · 05-18-2010, 01:44 PM

What a Bad wheel bearing sounds like

Because I'm Bad, I'm Bad-Come On
(Bad Bad-Really, Really Bad)
You Know I'm Bad,achoo! EXCUSE ME YOUR EXCUSED
And The Whole World Has To
Answer Right Now
Just To Tell You Once Again,
Who's Bad . . .
:dance:

ARModen · 05-18-2010, 02:16 PM

Have you jacked it up and tried to spin it in neutral? I would think you'd be able to detect a bad bearing like if you have some wobble in the wheel rotation. I've never seen one go bad, so I'd check the CV joints, tire wear, and the brakes while you have it jacked up.

I'd also check the air filter, and intake piping since it's over on that side.

extanker · 05-18-2010, 02:21 PM

Quote:

Originally Posted by boxster6354

What a Bad wheel bearing sounds like

Because I'm Bad, I'm Bad-Come On
(Bad Bad-Really, Really Bad)
You Know I'm Bad,achoo! EXCUSE ME YOUR EXCUSED
And The Whole World Has To
Answer Right Now
Just To Tell You Once Again,
Who's Bad . . .
:dance:

bad bearing...no dessert for you

husker boxster · 05-18-2010, 06:00 PM

Rear bearings definitely go out on Boxsters (search wheel bearing). What yr is yours and is it base or S? The rears seem to be particularly weak on 2001 Ss.

I had an 01S that had a rt rear go bad. Can't help you on the sound - I couldn't hear anything but the mechanic at the dealer said it was bad. It did sound quieter in the cabin after it was replaced - less what I would call "road noise".

sasha055 · 05-18-2010, 10:07 PM

I have a 2000 base boxster.

What should I look for when rotating the wheel on a jacked car?

Thanks
Sasha

extanker · 05-19-2010, 06:28 AM

look/feel for play..another way is to have a mechanic put the car on a lift and check them with the car running in gear..listening for a whirling,grinding,growling noise...its easier to find it if you dont have a posi

pothole · 05-19-2010, 07:37 AM

In my experience when they are really shot they sometimes make a sort of whom-whom-whom-whom-whom sound that changes frequency depending on speed. But they can make all sorts of weird and wonderful noises on the way out.

ppbon · 05-19-2010, 09:49 AM

Many times worn or noisy tires can be mistaken for bad bearings.
One way to tell if it's the bearing is to drive at the speed where it's the loudest. then swerve briskly to one side, then the other.
If the sound (tone) changes, most likely it's a bad bearing.
If the sound remains the same, most likely it's the tires.
Happy Boxstering,
Pedro

Boxtaboy · 05-19-2010, 09:59 AM

Pedro, by that logic, if it's the tires, shouldn't the "whom whom" sound be more prevalent even more when the top is down than when it is up? I have what I think is a bad rear wheel bearing sound, but I hear it more when he top is up at, and traveling at around 40mph. The sound seems prevalent even when coasting down to 5mph, but seems to disappear after 50mph. Also, when top is down, I can hardly notice the noise.

When I make a sudden turn of steering wheel, the noises do not change. When I lift the car and turn or pull on the wheel/tires, no noises. Sound has been going on for years with different sets of tires. Not loud to the point of driving me crazy, so haven't done anything about it, but is occasionally annoying.

jcb986 · 05-19-2010, 11:54 AM

I agree with Pedro on the bearing/tire noise. When a bearing goes bad it's because grease has escape and the bearing is overheating from friction and is beginning to breakup. The sound is something like driving on a paved country road with those little rocks at the surface. You also should here it about 20-30 mph miles an hour...loudest at about 50-60. Also check your trans-axle. Have you had your alignment checked.

sasha055 · 05-19-2010, 12:53 PM

Thanks for all the great responses.
At 20mph there is no sound.. it's quiet.

How can I check my transaxle? what should I look for?

My car has 70K miles on it, I had an alignment 2 month ago.. I can't really tell if noise were there before or not since I had the alignment done 3 weeks after I bought the car.

Thanks
Sasha

jcb986 · 05-19-2010, 04:20 PM

Is your Box a stick. Have you seen any oil from around the trans where the axle connects. The diff has about one liter of 90 weight oil. If the diff gets low you can develop a roar like noise from it and only notice it at a higher speed. I would jack it up, look and see if the boots are not broken and check the trans. By narrowing down the problem areas you closer to solving your problem.

PS: I just checked on how to change the rear wheel bearing and that is a lot of work. You need to press out the old bearing and press in a new one. Find a Indy near you.
Check here to see how it's done. http://boxcar-racing.com/forum/index.php?topic=562.0

sasha055 · 05-19-2010, 05:07 PM

It's manual transmission.. and there's no oil drips on my garage floor.
How do I check oil level in differential?

Sasha

sasha055 · 05-19-2010, 06:56 PM

After researching differential n the net I found out that differential and transmission share the oil..

So I should just change transmission fluid right?

Also I found following link http://www.pelicanparts.com/catalog/shopcart/986M/POR_986M_SUSaxl_pg1.htm

They sell differential oil.. but they mention front and rear differential... it's confusing.. should I buy 3lt of this oil from pelicanparts and change my transmission fluid? will this solve "low differential oil problem"?

Thanks
Sasha

sasha055 · 05-20-2010, 12:44 PM

I inspected CV boots axle and tire wiggling all apeear to be good..

I noticed a small drip of liquid near passenger side rear tire.
It comes from something that looks like a cut rubber hose about 5cm to the center and front from CV boot. I couldn't really tell what the liquid was.. it was yellowish without smell.

Can anyone please tell me wht that "cut rubber hose" is for? and what kind of liquid could be coming from there?

Thanks
Sasha

extanker · 05-20-2010, 02:33 PM

have a mechanic check your car

jcb986 · 05-20-2010, 04:47 PM

Quote:

Originally Posted by sasha055

I inspected CV boots axle and tire wiggling all apeear to be good..

I noticed a small drip of liquid near passenger side rear tire.
It comes from something that looks like a cut rubber hose about 5cm to the center and front from CV boot. I couldn't really tell what the liquid was.. it was yellowish without smell.

Can anyone please tell me wht that "cut rubber hose" is for? and what kind of liquid could be coming from there?

Thanks
Sasha

Sounds like one of the body drains. Did you have this noise before you replaced the tires. What kind of tires did you put on the Box. Did a Porsche shop or Indy do the alignment. The cambor and toe need to be set to Porsche specs, but, if your Box has hit something from the previous owner, then those specs may cause the tire to whine. They need to measure it to make sure it is true.

sasha055 · 05-20-2010, 05:11 PM

I didn't change tires.. I bought the car in feb, previous owner changed rear tires.. I aligned them at les shwab's.

I'm not sure how it was before.. I myself didn't notice the noise until recently... but then again I thought that crazy vibration at 3k rpm, extremely hard shifting and paying 1000$ for "brake job" to dealer is normal...

It's my first used car.. and I'm freaking out from time to time

Thanks for all the good advice!

Sasha

trube78 · 05-20-2010, 08:37 PM

I had the drivers rear go bad. It squealed rather loudly but was most noticeable at about the 20 to 40 MPH range when driving window down with a wall along side the car (on a bridge, in a city, etc.) At highway speeds road noise was too loud to hear the squeal.
I verified it was bad by:
1. Washing the car and pressure washing the wheel area. Small pebbles in the brakes/shrouds can cause a similar problem.
2. Drive at a speed where you hear the squeal. Change lanes back and forth (or turn) without changing speed it will momentarily get louder or go away (If you can drive by a friend at speed he will hear it when you do not. The squeal is very audible outside the car not in it without a reflective surface alongside the car.)
3. Jack up the rear of the car (both sides) and put on jack stands. Remove the wheels and verify the brakes and e brakes are retracting.
4. Check for rubbing of the medal shroud around the disk. On two occasions I have fixed a squeal after a state inspection of the brakes (they replaced the wheel without using the alignment pin -- a difficult task if you are not talented/careful)
5. Spin the hub. I could feel it dragging in comparison to the other hub. As I increased speed the bad side made a rubbing sound the other did not.
6. The on road tests may indicate a problem due to wheel alignment, tire wear, or balance issues. So if you hear a noise on the road do both the garage tests.

If you are hearing a whoomp, whoomp, whoomp vice a squeal the bearing is about to fail which can double or triple your repair cost. So get it fixed now!!

I have done bearings on about 30 cars. Modern American, Old British, Japanese, I would not hesitate to do most repairs but this is a bit more difficult and requires tools you probably do not have access to. It cost north of $600 at a dealer for the repair (obviously depends on the area/dealer.) A decent local shop can do the job and usually asks about $300. If they hesitate or admit they have not done this repair before -- I would go else where.
Hope this helps.
ATB,
tom