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

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