clunk in rear when going over bumps

dcramer · 10-26-2012, 02:51 PM

I suspect this is a control arm bushing but wondering if anyone has any other ideas.

I thought it was the muffler, as it happens in corners, but I'm pretty sure it's not. I hear it when I back out of my driveway over the little lip between the road and driveway, mostly when I am on an angle to the bump. Or going around corners.

There's nothing obviously loose. The normal places have been checked. RTAB, and the shock mounts are good.

Anyone ?

Dave

InfiniteDice · 10-26-2012, 03:12 PM

Peel the interior trim back on the sides of the trunk. Bounce the car and watch for excessive movement in the shock mounts.

Ahh with your car not sure if you need to peel the cover back or if they poke out, or have an access hatch of some kind.

Could be a number of things, including a broken muffler hanger. Just take a look.

hockeyfan27 · 10-30-2012, 10:34 AM

I have a similar issue but the noise is not consistent and difficult to reproduce. Usually it goes away on the trip to StanceFactory. Hasn't come back since I had it checked out last.

I'm in to see what you dig up.

**T.Dot_E30** · 10-30-2012, 11:31 AM

Same, haven't pin pointed it. I changed my shock mounts, still there. Changed RTAB still there.

Next I'm just going to rebuild the the whole rear end and change all bushings/rear ball joints. It could be anything from a diff bolt to a sub frame bushing to a rear ball joint, I just can't pin point it, so the plan was to do all at once.

Nick_V · 10-30-2012, 11:48 AM

This is a long shot, but you guys should check your parking brakes. I had a rear spring break on me, resulting in the retainers for the brake shoes being partially ripped out of the backing plate. It would cause occasional binding of the shoes on the rotor which manifested as a pretty violent clunk. It was also sporadic and hard to reproduce. I replaced the RTABS to no avail and was losing my mind poring over all the rear end components trying to find the problem. Checking the parking brakes was a desperate last-gasp effort (seemed the least likely culprit) but ended up being the problem.

It's worth a look.

hockeyfan27 · 10-30-2012, 11:57 AM

best explanation I've heard so far, "make sure the hooker is 100% dead before you stuff them in the trunk"

nevin · 10-30-2012, 12:23 PM

+1 on the parking brake. I had the shoe-retaining quarter-turn fasteners pull out of the dust guard. Parking brake would randomly engage while driving, felt like my tranny/diff/rear end was about to explode. Only clue was a subtle brake dragging noise when buildings reflected my car noise back to me.

sb_600 · 10-30-2012, 12:39 PM

could also be a swaybar endlink...

Dinanstu · 11-02-2012, 07:06 AM

Pull the mats from the trunk and examine the metal mounts that the shock(s) is(are) mounted to. Look for hair-line fractures in the metal from fatigue.

It happened to me...

dcramer · 11-02-2012, 07:18 AM

Quote:

Originally Posted by T.Dot_E30

Same, haven't pin pointed it. I changed my shock mounts, still there. Changed RTAB still there.

Next I'm just going to rebuild the the whole rear end and change all bushings/rear ball joints. It could be anything from a diff bolt to a sub frame bushing to a rear ball joint, I just can't pin point it, so the plan was to do all at once.

Hmmm. I"m thinking inner bushing but of course the exhaust is on that side which makes it even more of a PITA to do .

going to shannonville tomorrow, one last kick at the can, then I will start tearing it apart.

I'm with you though, one of those bushings must be the problem.

Dave

Dinanstu · 11-02-2012, 09:53 AM

You never mentioned if you examined this...

dcramer · 11-02-2012, 09:57 AM

In my first post I said I have checked all the usual suspects. Including the shock mounts.

Additionally I didn't mention that I heard the clunk when jacking the car up the other day. I lifted one side up quite high and it clunked.

Dave

Dinanstu · 11-02-2012, 10:29 AM

I had to be certain. Some people check the integrity of the rubber mount but not the metal piece.

Subframe bushings might need to be changed...Also check the subframe itself for integrity. If thats the case, change them anyways..

**T.Dot_E30** · 11-02-2012, 10:49 AM

That's a good point, I've been checking that area for cracks each time I look at my mounts but haven't found anything.
My trunk carpet has been out for years, so I do have easy access to it. My shocks have been in and out many times due to the stupid externally adjustable koni setup.

Blades · 11-02-2012, 01:17 PM

it could be hundreds of things .. you could be a loose tire iron or spare tire