My clunk...

[freebass55]

While at the track the other night I had a loud “clunk” while launching on my last run. It sounded like it was coming from the rear end. On my way home, I couldn’t reproduce the sound until I put the car into reverse. I heard it again, just not as loud. Yesterday, I got back under the car. I checked everything that I recently installed, and it was all tight. One thing I did notice, was that the locking nut’s metal flange (or whatever it is) for the LCA on the passenger side was sitting on my rear sway bar. I adjusted that thinking it might fix the problem. I also changed the wheels back to stock, and noticed that if I pull on a wheel, I hear a clunk. Everything was tight, the lugs were not loose and torqued to spec. Now when I push/pull the wheel moves a hair, nothing drastic, but enough to move, and make a sound. And it happens on both sides. Is this normal? If so, what’s the reason?

If that’s not the problem I have no idea where else to look. Could the shifter be the problem? It’s the only other thing I installed, and didn’t check. Anyone have any other ideas?

 

[cekim]

If that’s not the problem I have no idea where else to look. Could the shifter be the problem? It’s the only other thing I installed, and didn’t check. Anyone have any other ideas?

There are a couple of "clunks" that are "normal" in our read-ends:
1. play/slap in the driveline (and how!) - you can hear this one by putting the trans in neutral and rotating the driveshaft back and forth. You will hear the pinion hit the ring gear as well as some slap in the transmission.

2. bottoming out on the axle snubbers (does the metal over the snubber look like it has been "rubbed"?) I have noticed there isn't much room for lowering with the snubber as it comes stock - I have cut off a significant amount of material from tha thing after lowering my cars.

The axle should be pressed against the C-clip retainer inside, so you shouldn't be able to move it in and out without significant force. So any clunk you hear there, I would hope comes from rotating the tire (which will produce the same clunk as rotating the driveshaft...

A loose jam nut on an adjustible LCA would definitely leave room for some clunking...

 

[freebass55]

There are a couple of "clunks" that are "normal" in our read-ends:
1. play/slap in the driveline (and how!) - you can hear this one by putting the trans in neutral and rotating the driveshaft back and forth. You will hear the pinion hit the ring gear as well as some slap in the transmission.

2. bottoming out on the axle snubbers (does the metal over the snubber look like it has been "rubbed"?) I have noticed there isn't much room for lowering with the snubber as it comes stock - I have cut off a significant amount of material from tha thing after lowering my cars.

The axle should be pressed against the C-clip retainer inside, so you shouldn't be able to move it in and out without significant force. So any clunk you hear there, I would hope comes from rotating the tire (which will produce the same clunk as rotating the driveshaft...

A loose jam nut on an adjustible LCA would definitely leave room for some clunking...

O.k.,
1. I can hear this all the time, I think. The cluck was a lot more pronounced, that's why I am worried.
2. What's the axle snubber?

This clunk is from pulling on the tire, so I am facing the rear tire and pulling away from the car, then pushing the whole tire back in.

And, I have non-adjustable LCA's.

BTW, thanks for the reply.

 

[cekim]

O.k.,
1. I can hear this all the time, I think. The cluck was a lot more pronounced, that's why I am worried.
2. What's the axle snubber?

reddish/brownish rubber thing on other side of the axle pointed up torwards the body - looks like a dog toy - it keeps the metal of the axle from hitting the frame if the car bottoms out, but there isn't a lot of clearance left on these cars, so even a 1-1 1/2 lowering leaves these things pretty close to the body...

This clunk is from pulling on the tire, so I am facing the rear tire and pulling away from the car, then pushing the whole tire back in.

- Can you pull on the LCA and get the same noise?

- Can you tell if the tire/axle are moving relative to the car?

- Have you losened your pan-hard at any point? Checked that it is tight? It keeps the rear-end from moving left-to-right..