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xanderdeg · Posted: Thu May 23, 2013 4:47 am Post subject: rear brake noise

My right rear drum is making a metal on metal thunking noise as she wheel turns ie: once per revolution it goes thunk...

I opened up the drum, nothing loose in there.

I would be inclined to believe it to be a bad CV joint or bearing except for the fact that the noise goes away when I brake...

There is no noise when I turn the wheel while it is jacked up and suspended...

Any idea what is going on? Its like my car has a phantom menace

xanderdeg · Posted: Thu May 23, 2013 5:10 am Post subject:

New (very odd) development...

I live on top of a hill, so I decided to take it down the hill with the engine off so i could hear the sound better and hopefully figure out what it was. After one run down my hill which included some hard swerves and braking, the noise stopped....

I went down one more time, still no noise.

I'll see if it resurfaces after more driving, but for now it's gone...

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Make sure you are adjusted properly.
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WeiBe (1987 924S 2.5t) - 931 S3

xanderdeg · Posted: Thu May 23, 2013 6:55 am Post subject:

Will do. Is there a specific way to adjust them properly and evenly?

The sound came back after about a mile of driving...

hbsoftware · Joined: 21 May 2013 Posts: 13 Location: PORTUGAL

exactly same thing happened to me...i removed the drum and there was a loose washer inside...i dont know where it came from...i reinstalled the drum and the noise never came back

emoore924 · Joined: 13 Apr 2004 Posts: 2822

Yes, there is a procedure in Haynes. Not being a drum guy, I don't know what it is. Something about a star adjustor or something. And you need to be sure the shoe expander is retracting properly and not stuck/sticky.

Not sure if the e-brake is part of the drum structure but you might want to check that is ok as well.

I'm sure there's a ton of stuff if you search...

xanderdeg · Posted: Sat May 25, 2013 5:55 pm Post subject:

New development!!

So I did some.more troubleshooting with a friend and he says the sound is definitely coming from the front right when you listen from outside the car...

The sound goes away when I brake, as well as when I turn..

The noise is getting progressively louder as time goes on. I stopped driving it tonight because I was worried it would cause worse damage than what might already be done.

I have no clue what it could be...

Any ideas?

Ozzie · Posted: Sun May 26, 2013 8:06 am Post subject:

check your discs for thickness and warping.
check your pads
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

scriblz7 · Joined: 07 Dec 2008 Posts: 112 Location: kirkland WA.

make sure all lug nuts/bolts are tight
_________________
Riley
79 924 n/a with gt body
15 VW GTI

Paul · Posted: Sun May 26, 2013 9:43 am Post subject:

Check your front wheel bearings.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
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Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

xanderdeg · Posted: Tue May 28, 2013 2:11 am Post subject:

Pulled off the front wheel and the lugs seemed hand tight but i doubt that was the problem...

The brake disc (or rotor i'm not sure what to call them) is straight and true. When i turn it by hand there is no discernable noise...

The pads were in constant contact with the disc so i'll be checking the piston seals later today when i have time.

CorsePerVita · Joined: 25 Jul 2008 Posts: 1992 Location: Redmond, Oregon

ditch68 · Joined: 29 Sep 2008 Posts: 126 Location: Tucson, Az

Jack up the car, with the wheel on, grab the top and pull in and out. If there is movement or clunking, you have a bad wheel bearing (very likely based on your description).

Applying the brakes could quiet the noise even if it is a bearing, because the braking action pulls everything tight and forces the worn parts together, if you get what I am saying. So don't necessarily assume it is brakes because of the relationship with braking/noise correlation.

Jeff
_________________
Current:
1979 924, all stock.
1988 951 all track modded out and angry.

Past: 1986 951, 1988 924S, 1965 912 with '69 911T engine.

xanderdeg · Posted: Thu May 30, 2013 1:30 pm Post subject:

Sound came back today, did the shake test with no results.

One of the wheel bolts was ridiculously loose, maybe that's the problem. Only time will tell.