Growling sound from right rear., What could be causing it? Options

[FourBlades]

George and his friend Marc and I have been working on George's Chump Car.

We have made a lot of progress we need to post.

One problem is a pretty loud growling coming from the right rear.

It gets louder and softer with changes in speed.

I pulled the caliper last night and the pistons were defintely stuck.

I was able to free the inside but the outside is buggered.

The caliper was gripping tight enough I could barely get it off the rotor.

I plan to swap in a caliper from another car tonight and see what happens.

We are trying to go to a DE this coming weekend so we don't have a ton of time.

What else could be causing the problem?

The wheel is very stable when grabbing it and wiggling it back and forth.

If the bearing is going bad, would it cause the wheel to wobble noticeably?

We also suspect it could be the CV.

Any thoughts about the situation (other than it sucks)?

John

[914itis]

Had a similar noise, It was louder with the top on, I check my bearings, and was leaning towards the transmission. Last week, I changed my rear tires and noise is gone.

[ThePaintedMan]

(IMG:style_emoticons/default/headbang.gif) Thought I had most of the problems figured out, but this is one that I hadn't sorted out before I brought the car to John.

As John said, its a deep growling sound. Other information that might be of help:

1) When I replaced the trailing arm bushings, I also adjusted the venting clearance, but had a hard time getting them setup to spec. I knew the brakes would have to be sent to Eric sooner or later. However, now that John mentioned the pistons being stuck, it makes more sense why I was having issues.

2) The tires are brand new, and the noise was the same as the previous set.

3) The CVs were recently checked, cleaned and repacked. No "clunking" when going around turns.

4) Bearings, as John said, do not appear to have any axial play.

5) No significant vibrations or imbalance. (Right John?)

[76-914]

(IMG:style_emoticons/default/headbang.gif) Thought I had most of the problems figured out, but this is one that I hadn't sorted out before I brought the car to John.

As John said, its a deep growling sound. Other information that might be of help:

1) When I replaced the trailing arm bushings, I also adjusted the venting clearance, but had a hard time getting them setup to spec. I knew the brakes would have to be sent to Eric sooner or later. However, now that John mentioned the pistons being stuck, it makes more sense why I was having issues.

2) The tires are brand new, and the noise was the same as the previous set.

3) The CVs were recently checked, cleaned and repacked. No "clunking" when going around turns.

4) Bearings, as John said, do not appear to have any axial play.

5) No significant vibrations or imbalance. (Right John?)

Any pitch change in the turns? Any pitch change between acceleration, cruise and deceleration? Any temp variation on the hubs after a run. Does the noise start immediately or after a few miles?

[rjames]

My vehicle was making a growling noise that turned out to be a wheel bearing even though I could not detect any play in the wheel when grabbing it. When car was turning it would all but disappear.

I have a new similar noise that is likely a bearing in the transmission. I haven't fixed it yet...

Thread on diagnosing what that sounds like:
http://www.914world.com/bbs2/index.php?sho...hl=Transmission

[FourBlades]

Some other facts, the car handles great.

The noise seems independent of cruising, accelerating or braking.

Local Porsche dealer said wheel bearing was their best guess.

John

[ThePaintedMan]

John,

The more I read about it and think about it, I think it's a wheel bearing too. Trying the brake idea might be it, but I don't remember hitting the brakes making the noise change...

RockAuto.com has bearings for $55 a piece, and I can have them overnighted. The trick is I don't know how hard it is to change them. Eric's write-up looked pretty intense.

[no1uno]

George and John,

I may have the bearings at my house. They are on my to do list. You can have them if it helps save some time/expense with overnighting them. Just replace them in the future

[scott_in_nh]

John,

The more I read about it and think about it, I think it's a wheel bearing too. Trying the brake idea might be it, but I don't remember hitting the brakes making the noise change...

RockAuto.com has bearings for $55 a piece, and I can have them overnighted. The trick is I don't know how hard it is to change them. Eric's write-up looked pretty intense.

It isn't mechanically that difficult to do it in the car.
Best advice I can give is be sure to have a big enough hammer on the order of 5lbs.(small sledge really).!

Trying to pound them out with a large ballpeen won't do it....

Be sure to freeze the new bearing before installing.

[ellisor3]

If you are sure it is coming from one side, I would bet on wheel bearing. I am about to swap a transaxle because of a similar noise, but it is from a main shaft bearing going bad.

[FourBlades]

It is definitely coming from the right side (famous last words).

I am pretty sure I read somewhere that Porsche used the same rear wheel bearing all the way through the 996, so the Porsche dealer probably has them in stock.

Can anyone confirm that these are the same bearings for 911s?

John

[ThePaintedMan]

John,
Pelican is showing that number for the 911 from 69-73. The newer 911s are close to the same number, but not the same.

Definitely could use someone else's expert opinion to verify though.

[McMark]

They're used in tons of cars, including Boxsters at all four wheels.

Check out this link for part numbers.

[ThePaintedMan]

Thanks Mark! So if they fit Boxsters, they should have them.

Thank you for the offer Jon!

[FourBlades]

Came home this evening and pulled a caliper off my red car.

Cleaned it up, adjusted it and installed it on Das Chumpenauto.

Bled all brakes like crazy.

Noise is still there, arrgh!

Going to get Porsche of Melbourne to replace the wheel bearing tomorrow.

I am bringing my shop manual and URLs for Eric Shea's videos to make sure they have no issues.

John

[76-914]

Came home this evening and pulled a caliper off my red car.

Cleaned it up, adjusted it and installed it on Das Chumpenauto.

Bled all brakes like crazy.

Noise is still there, arrgh!

Going to get Porsche of Melbourne to replace the wheel bearing tomorrow.

I am bringing my shop manual and URLs for Eric Shea's videos to make sure they have no issues.

John

IIRC, last time I checked PMB had the best price on those bearings.

[FourBlades]

Dealer replaced the bearing and all is quiet now!!! (IMG:style_emoticons/default/piratenanner.gif)

John

[FourBlades]

George and John,

I may have the bearings at my house. They are on my to do list. You can have them if it helps save some time/expense with overnighting them. Just replace them in the future

Thanks for the offer!

We need to get all the locals together for beers soon.

John

[bandjoey]

Hi John. Did the dealer do this on the car or take the trailing arm off and need an alignment? Approximate cost? Thanks

[Drums66]

.......GGGGRRRRRRRRRRRRRR.......BEARINGS?? (IMG:style_emoticons/default/idea.gif)
(IMG:style_emoticons/default/popcorn[1].gif) (IMG:style_emoticons/default/popcorn[1].gif) (IMG:style_emoticons/default/bye1.gif)