Check the swaybar links. May be loose. Do you have the "clunk" over a bump as well? This is the first thing I look for.

 

Yes, it happens sometimes, but not all the time going over bumps such as speed bumps in a parking lot. One thing I noticed about it this morning is that when turning in a continuous turn, that it clunks several times instead of just once. I tried this out in the empty parking lot this morning.

Regarding the swaybar links, are there any other suspension bushings that may be worn out that I would need to have someone look at and replace also?

Thanks.

 

Well, technically any of them could be warn and in need of replacement. I have only done swaybar links until past 200k miles. My 00 and 02 both needed front links at 180k and rear at 150-170ish. They get loose and then wear fast, but that clinking and rattling drives me insane! Its not an expensive fix either

 

One thing I noticed about it this morning is that when turning in a continuous turn, that it clunks several times instead of just once.

If the car is turning circles on a paved surface such as a mall shopping center lot, and clunking, I tend to doubt (but not absolutely eliminate) the swaybar links being the cause.

What is happening at the rear suspension (accepting at this point that this is where it's coming from) when making tight turns? Not much except that the two wheels, axles and side gears in the rear differential are turning at different speeds and the spider gears in the differential are turning much more than when going straight. If the clunk appears on turns, but not much when going straight then . . .

This suggests a couple of other possibilities. The AWD transfer mechanism is binding. If the car is an automatic, it's the multi-plate transfer clutch, and if a manual, the viscous coupler. When binding occurs during tight turns, they cause torque to build up in the drive train. Eventually, one or more wheels will slip or "hop", releasing the torque pressure, and that can lead to a clunk from the drive train.

Another possibility is a defect in the rear differential -- perhaps a damaged gear tooth, that "clunks" as it comes around, which might be only when the car is turning (e.g, a spider gear). In this regard, if making a tight circle, does the clunk repeat regularly?

If the car is an automatic, use the AWD disabling fuse to turn off the AWD. (The AWD warning light should come on in the instrument panel.) Then do some tight turns and see if the clunking is still there. If the clutch is released, there should be no build up of torque. (The clutch can become mechanically locked in which case the fuse won't free it up, but this test is the first that should be tried.)

For the differential, one possible check would be to raise one rear wheel, and with the car in neutral, turn that wheel, and listen for the noise, or a periodic binding.

The swaybar and links are fairly easy to inspect so it's probably a good idea in any event.

Let us know what you find.

 

Another possibility is a defect in the rear differential -- perhaps a damaged gear tooth, that "clunks" as it comes around, which might be only when the car is turning (e.g, a spider gear). In this regard, if making a tight circle, does the clunk repeat regularly?

When making a tight circle, it doesn't clunk continuously, it seems to depend on how sharp or tight the turn is.

I am afraid it could be something in the rear differential, if so, should this be something that needs to go to the dealer for repair? I'm not sure that my small tire/brake service shop can handle these more in-depth repairs.

Would a rear CV joint cause the same noise or would CV problems exhibit a constant noise regardless if the vehicle was going straight or turning?


Thanks for the suggestions so far, any other ideas?

 

Although rare, a rear axle CV joint will make noise at all times, not just when turning, because there's no change in the CV angle when turning. (It's different on the front, where the angle at the outer joints change with the steering angle.)

If it's an automatic, try the AWD fuse. (It's something you can do on your own. See the "in case of emergency" section of the Owners Manual, the part about replacing a flat tire.)

As for the differential, try the one-wheel-up test (on both sides). If you can't do this yourself, then any mechanic should be capable. (The differentials are rarely repaired -- usually just replaced -- but they don't often fail; it's just a possibility.)

The service shop should be able to inspect the sway bar and links, and indeed the whole rear suspension, for broken or bent parts, or worn or cracked rubber bushings.

 

Just got back from the dealer, it turned out to be the front axles that need to be replaced. About $375 for both before taxes and a 15% parts discount that they are currently running.

Thanks for the help on the board.

 

2011 Forester. Just purchased pre-owned Forester from Subaru dealership. Did not notice the steering wheel vibration when on test drive. Once on the smooth highway, vibration became quite apparent. Very noticeable when holding steering wheel lightly. Can can feel through seat at times. Hopefully just a tire balancing to fix. Plan on taking back to dealership to take a look at it. What other potential issues other than wheel balancing?