I searched the archives and found a thread about someone that had a "thunk" around thier rear passenger wheel. Control arm links were mentioned and I will be checking that out. What is different about my situation is that the "clunk" (it actually sounds more like something binding up and then releasing) only occurs when I start to back up....and it only happens once. On one occasion it even seemed at though the binding was enough to slow the progression of reverse movement. It only happens in reverse and only occurs once per movement. If I brake while in reverse and then proceed to move backward the sound does not occur again. There is no specific noise from the same area when moving forward.

Besides the control arm links and the general state of things that should be tight, is there anything else that I should specifically look at?

 

My 98 V70 GLT/AWD has just started this behavior though it happens both forward and reverse -- I haven't found any answers yet. I just added new thread with detailed description.

 

I'm no expert, but I do have an idea. Binding caliper? The clue is that using the brake "solves" the problem. Testing might involve jacking the offending wheel off the ground and trying to "roll" it backwards to see if the caliper is sticking. Or maybe having someone else s l o w l y back the car up while you're inspecting the caliper. Clue #2 is that its no problem until the car again sits still. When were the slides last lubed? Are you in a road salting area? Easy to check.

 

Here is a brief update: I had a call at work the other day from my wife who stated that she was backing out of the driveway and the rear driver's side wheel just locked up. I ran home to check it out and found that the wheel was frozen in place. I jacked the car up, took the tire off and checked everything (as able with limited time). There was nothing obviously wrong. Since there's not much back there to go bad, and since I had to get back to work, I decided to pull the car back into the garage (dragging the stuck wheel) and let my wife use my car until I could take things apart for a better inspection. As I was pulling the car back into the garage, the wheel suddenly "popped" loose and rolled freely with no associated noise during movement. I took the car around the block and had no more problems. I did pull up the parking brake lever to "clean" the pads of any rust while slowly cruising up the street. I haven't had a chance to pull things apart yet, but haven't had any more problems either. In fact, the whole clunking, thunking thing has completely stopped. I'm not sure if I need to just leave well enough alone or pull things apart to see if I can identify what caused the problem in the first place. Any suggesting anyone????

 

You can check if the caliper is stuck, drive the car normally and when you stop feel the temperature of the rims,if the one you have problems with is hotter than the other one then possibly the caliper it's stuck.

 

On serveral occasions, I've experienced a clunk-like release on backing-up my 2003 xc70. On one occasion, the (passenger-side) rear wheel did not release at all on backing up. Reversing direction to forward did not release the wheel. After jacking up the car I was able to rotate the wheel about 5-10 degrees without apparent binding (i.e. not a brake caliper problem). Rather, rotation was limited by hard-stop somewhere in the drive-train. Interesting, repeating the 5-10 degree travel several times resulted in a sudden release of the wheel. No problem since, though I did hear a clunky-like release backing up this morning. Any insight would be appreciated.