Diagnosing a "clunk" in the right rear

[RandallNeighbour]

I'm headed off to a DE at the end of the month and I'd really like to find and replace whatever is making a clunking sound when I drive over uneven pavement or through a pothole.

I replaced the entire suspension and wheel bearings on the car 3 years ago with factory parts and I've only put about 7,500 miles on the car, although it has been to the track 3-4 times in those 3 years. Additionally, about six months ago I replaced the front motor mount thinking that might be part of the problem (which wasn't all that worn out, believe it or not).

What's the fastest way to determine what's worn out and making noise without removing parts to inspect them or guessing what might be wrong and replacing it when it may not need replacement?

I thought of putting the back of the car on ramps and going under it with a rubber mallet and tapping away to see if I could hear something. Do you think that might isolate the area in need of work?

BTW - Before you reply, I fully realize that the trailing arms create this clucking sound, so I don't need a reply with "change your trailing arm". What I'm looking for here is how the suspension can be inspected, not diagnosed without examining the car. Thanks!

[Bruce Wayne]

mine did that too.. it only stopped when i let the midget out of the trunk.

[Bruce Wayne]

could be the anti roll bar bushes.. before you let the midget run away slid him under the car to have a look.

drop links probably wont show if the car has weight on the wheels as the drop links will be at one end of their travel, and if you jack it up then with the weight unloaded, they'll be at the opposite end of their travel.

the clunking from the drop links is the metal ball impacting the plastic socket they reside in as they move about from upload/download. you can have a look and see if the rubber boots are split, but that wont give you an idea of the inside wear.

for the anti roll bar bush, you'll see if the rubber bush is distorted (or the midget will)

[RandallNeighbour]

Forgot to mention that I replaced the rear anti-roll bar bushings last year. They were easier to get to than the fronts, so I remember doing them.

Might be the drop link, but I think I replaced them last year with Porsche units.

If neither of these things are the issue, it might just be that trailing arm... I wonder how I can test it without removing it? Hmmm.

[mistermac99]

Originally Posted by RandallNeighbour

Forgot to mention that I replaced the rear anti-roll bar bushings last year. They were easier to get to than the fronts, so I remember doing them.

Might be the drop link, but I think I replaced them last year with Porsche units.

If neither of these things are the issue, it might just be that trailing arm... I wonder how I can test it without removing it? Hmmm.

My car made this sound last year when I bought it, drove me carzy.
I dropped it off at the Indy, and he took the carpet and engine cover off and rode around like that until he determined it was in fact the trailing arm.

No more clucking sound now! This may work for you.

[RandallNeighbour]

Well, I spent the better part of the day fixing my "clunk" sound in the back of the car.

On visual inspection with a flashlight, I could see the center bushings in the lower control arm were shot. I happened to have a couple of control arms on hand (got a killer deal on them and couldn't resist ... $22 each for rebuilds!)

This is the bushing that holds the trailing arm fork in place, and my track arms looked almost new and the poly bushings were good.

So I replaced both rear lower control arms, changed the oil, bled the brakes, and swapped out a melted brake wear sensor (odd) and took it for a drive.

No clunk now.

Apparently, when I replaced the "entire suspension" a couple of years ago I must not have replaced those lower control arms. My memory is getting worse and worse.

At any rate, for those of you lurking on this forum thinking you'll pick up an inexpensive boxster with high mileage, and enjoy it, think again! These cars seem to wear out suspension parts far faster than say, a Toyota... even when they're not driven hard on a track. Go figure.

[Verhag]

Curious.....I have less than 1000 miles on 2000 S....experiencing the same "clunking" from what seems to be right rear. To me it gets more pronounced the more the car warms up...when I pull out of garage it feels like new, tight,solid like one comes to expect in a German car....then affter afew miles, any little bit of rough road results in this "clunking" noise from rear end. Top down or up, the same. Sway bar is tight. Should I start with rear track arms (look like tuning forks) or front motor mount?

Willing to do it all, but I prefer to start one component at a time....suggestions?

[evo-r]

Originally Posted by Verhag

Curious.....I have less than 1000 miles on 2000 S....experiencing the same "clunking" from what seems to be right rear. To me it gets more pronounced the more the car warms up...when I pull out of garage it feels like new, tight,solid like one comes to expect in a German car....then affter afew miles, any little bit of rough road results in this "clunking" noise from rear end. Top down or up, the same. Sway bar is tight. Should I start with rear track arms (look like tuning forks) or front motor mount?

Willing to do it all, but I prefer to start one component at a time....suggestions?

My noise is more like "clock, clock..." when driving through bumpy rough roads at under 45mph (no noise at highway speed). The Porsche indy stated it's the rear trailing arms but he said there is no safety urgency to replace them just annoying. I'm planning on replacing them next spring.