SpeedySam14

I have been chasing a clunk for nearly 2 years. Here is all the info I have. It first started 2 years ago. It would happen when the front wheels were slightly turned and the front of the car was in grass, and then I would back up slowly to get into the asphalt. I would hear a clunk as the engine rpm increased to crest onto the asphalt.

Next occurrence is when I downshift from 2nd to 1st (a rare occasion) or 3rd to second. It happens sometimes when I accelerate during acceleration. It happens often enough when I let off the throttle. Sometimes the clunk sounds gradual (2 or 3 in a row as of something is slipping).

It got worse in winter. Then as temps increased it quieted down. Another observation is the car came slightly out of alignment for no apparent reason. Would that be LCA of subframe bushings or both? There is now a slight bare metal scuff on the inside of the driver wheel well. So I can tell something has moved when I combine that with the alignment being off.

Now the status is I had a shop put it in the lift. The lower control arm bushings are super rotted. They literally have holes in them. Car really doesn't drive poorly which is strange but just recently at a higher speed turn I heard a clunk and thought it was time to bring it in.

I changed the engine mounts thinking it was that. It's not. So what's left is subframe bushings or LCA bushings (which I would change the whole LCA). Thoughts?

I of course need the LCA. But I just assume have them also do subframe bushings (I know, a much bigger job) while they are in there. Car has 183k. The tech took a large bar at the subframe mounts and everything seemed tight.

Thank for your help!!

rottonj

iTrader: (4)

Have you replaced your sway bar end links? It wouldn't have anything to do with alignment but it's a sure spot for a clunking noise. I had a clunk in the rear I couldn't find as all looked good, replaced with Moog and that solved the issue.

Doug G

Control arm bushings, sub mounts, ball joints, tie rods, trans mount, motor mount.... could be any number of things.

What have you checked ?

SpeedySam14

Engine mounts changed. Sway bar end links changed. It sounds like a very significant clunk which only happens under weight transfer. I feel as if tie rod ends or ball joints would be more regular. This is still a noise that happens on some bumps, some accelerations, sometimes braking, some curves. What is the procedure for lower control arms vs subframe bushings? Would it make sense to do LCA first? Or should I just do both at once to save labor (or are they largely independent)

rottonj

iTrader: (4)

I don't think replacement of subframe bushings is an easy job, not sure that they can be slid in after removing the bolt so dropping it down may require stabilizing the motor and transmission. Hopefully someone who has info on that will chime in.

rottonj

iTrader: (4)

A worn strut bearing will make a clunk as well.

98CayenneT/A

Loose torque arm bolts on the diff. end will clunk

SpeedySam14

Forgot to mention all shocks/struts are new

SpeedySam14

Do you have a pic of diagram? It sounds like the clunk is more on the left and right and the diff is in the center i assume?

98CayenneT/A

The two bolts above the green dots

SpeedySam14

Thank you so much I will check that

rottonj

iTrader: (4)

That's an F Body, he is posting in the wrong forum. You can check all day we don't have that lol

98CayenneT/A

Ahhhh ****.... this is correct.

Sorry op, my mistake for sure!

SpeedySam14

no problem lol. I did poke my head u der and I was going to comment that my diff setup look nothing like that lol. I ordered Mevotech control arms. Going to put those in and see how it goes.

SpeedySam14

Annoyed to report New lower control arms did NOT solve my clunk. What else is left? This is a very siginificant clunk which happens during weight transfer of the engine. It is worst when I use manual mode to keep the car in 1st gear. I acce=lerate and then when i let off CLUNK. If I let back on heavily, CLUNK Super frustrating at this point. Is the only thing left subframe bushings?! I would like to eliminate everything since subframe bushings requires dropping the subframe

rottonj

iTrader: (4)

When you said you replaced the engine mounts did you do all 4? Top is the dog bone mount that also has the square bushing, drivers side is the transmission mount, front of vehicle can barely be seen and is a real bitch (these are the ones that usually break), and passenger rear (when these wear the motor usually sags to that side). Attempt to tighten all the sway bar end links as well, even a little movement will cause a clunk or if they are servicible make sure they are greased.

SpeedySam14

All engine mounts changed with the exception of the top dogbone which was changed about 80k ago and the rubber still looks good. The clunk comes from both the left and right side of the engine towards the outer edge of the engine bay depending on the clunk occurrence. Sway bar end links are new and tight but I will double check. It sounds like a very heavy clunk and given the thickness of the sway bar I doubt it could make that sound. It also sounds like the sound is almost towards the front of the engine and down low. (not the back where the sway bar is) Thank you though I will check

rottonj

iTrader: (4)

Sounds like you have covered everything, when you did the front struts I assume the strut bearings were replaced also. Sounds like it bangs under torque, which points to the motor mounts. Maybe bring it to a different shop and have a second opinion.

rottonj

iTrader: (4)

This is a good example of the dog bone mount issues , it's an easy install and if it hasn't been replaced in 80k it's time. They are inexpensive and you could also get poly upgrades. Just search the threads for that.

SpeedySam14

The strut bearing you refer to is the ring visible at the top right under the hood? I did Monroe quick struts so the whole units were changed. I am definitely thinking of bringing to another shop to diagnose.