Trying to locate a little clunk sound from the rear and looking for advice

[Jasper7821]

I recently bought a 2001 986 S (100k miles) and the prior owner thought maybe it was a rear strut. he tried for a while to locate it but could not.
It sounds like it's coming from the right rear, I thought maybe it was the strut but not sure. It's not a real heavy clunk like a worn strut, but more like a heavy tap sound.
When I hit a little bump I can hear a clunk, But going over a speed bump I cannot hear it.
If I drive over a cobblestone road I can hear it even when going slow as the tire goes over each stone.
Doesn't matter if it's in gear or neutral, the sound is the same.
If I push on the rear of the car it doesn't do it.

Just curious if there's some obvious things to look for.

[pilot4fn]

Originally Posted by Jasper7821

I recently bought a 2001 986 S (100k miles) and the prior owner thought maybe it was a rear strut. he tried for a while to locate it but could not.
It sounds like it's coming from the right rear, I thought maybe it was the strut but not sure. It's not a real heavy clunk like a worn strut, but more like a heavy tap sound.
When I hit a little bump I can hear a clunk, But going over a speed bump I cannot hear it.
If I drive over a cobblestone road I can hear it even when going slow as the tire goes over each stone.
Doesn't matter if it's in gear or neutral, the sound is the same.
If I push on the rear of the car it doesn't do it.

Just curious if there's some obvious things to look for.

I'm inclined to say that it is the rear 'fork arm' or what ever it is called for.
Number 8 on the attached picture.

[Jasper7821]

Originally Posted by pilot4fn

I'm inclined to say that it is the rear 'fork arm' or what ever it is called for.
Number 8 on the attached picture.

Interesting, thank you very much. I'll go tap on that and see if it's loose or worn out bushing or something.

[jcp]

That would be the 'control arm link' or 'rear track arm'. You will probably not be able to make it misbehave by tapping or pulling/pushing....I couldn't mine. It was the culprit though. Evidently it's the spherical joint at the forward end.
It can be changed by just raising the car for access. Remove the two noted bolts in the pic and pull the joint end of the arm toward the center of the car. When it comes clear of the bracket, pull it toward the front of the car enough to clear the fork to control arm connection, raise the fork enough to clear the control arm and move it (the track arm) toward the rear or of the car. The front of the track arm will drop down enough to move forward and out. This method worked on my '99. Also remember to torque the bolts properly....The fork end is in excess of 100 ft/lbs.

[Jasper7821]

Originally Posted by jcp

That would be the 'control arm link' or 'rear track arm'. You will probably not be able to make it misbehave by tapping or pulling/pushing....I couldn't mine. It was the culprit though. Evidently it's the spherical joint at the forward end.
It can be changed by just raising the car for access. Remove the two noted bolts in the pic and pull the joint end of the arm toward the center of the car. When it comes clear of the bracket, pull it toward the front of the car enough to clear the fork to control arm connection, raise the fork enough to clear the control arm and move it (the track arm) toward the rear or of the car. The front of the track arm will drop down enough to move forward and out. This method worked on my '99. Also remember to torque the bolts properly....The fork end is in excess of 100 ft/lbs.

Thank you, found it. $170.
https://www.pelicanparts.com/More_Info/98633104307M80.htm?pn=986-331-043-07-M80&bt=Y&fs=0&SVSVSI=1048

[Gilles]

Originally Posted by Jasper7821

Thank you, found it. $170.

Jasper, you should replace both sides..
.

[Jasper7821]

Originally Posted by Gilles

Jasper, you should replace both sides..
.

Thank you, ya makes sense to. Still have other repairs to do, I’ll get to this one in a month or so unless the sound gets worse.

[tonythetiger]

Originally Posted by Jasper7821

Thank you, found it. $170.
https://www.pelicanparts.com/More_Info/98633104307M80.htm?pn=986-331-043-07-M80&bt=Y&fs=0&SVSVSI=1048

if you shop around, they are usually around 125 each. I've just replaced everything once I'm in there, but I'm sure I spent money I didn't have to. The fork is the normal culprit for low-speed clunk and you can't tell until you replace it.
Look at the drop links and sway bar bushings as well, you can probably tell if those have issues from inspection. Dont forget, at that mileage, (100K?) your struts are likely worn also.
:+)

[Jasper7821]

Originally Posted by tonythetiger

if you shop around, they are usually around 125 each. I've just replaced everything once I'm in there, but I'm sure I spent money I didn't have to. The fork is the normal culprit for low-speed clunk and you can't tell until you replace it.
Look at the drop links and sway bar bushings as well, you can probably tell if those have issues from inspection. Dont forget, at that mileage, (100K?) your struts are likely worn also.
:+)

Thank you very much. Will dive into it maybe next month.

[morgal48]

$170/each? Shop around. Made by TRW for Porsche. Only difference is the Porsche logo is ground off. I bought both sides for less than $170. And they aren't that easy to change.. After you remove the track arms, before you start to install the new ones, be sure to have a jack under the wheel hub to adjust the height or you will have one devil of a time reinstalling the track arm. The LCA moves through x, y, and z axes. And the nut on the top of the front, non forked end is captive. Several videos on YT. Have fun.

[Jasper7821]

Originally Posted by morgal48

$170/each? Shop around. Made by TRW for Porsche. Only difference is the Porsche logo is ground off. I bought both sides for less than $170. And they aren't that easy to change.. After you remove the track arms, before you start to install the new ones, be sure to have a jack under the wheel hub to adjust the height or you will have one devil of a time reinstalling the track arm. The LCA moves through x, y, and z axes. And the nut on the top of the front, non forked end is captive. Several videos on YT. Have fun.

Thank you, last real work I did on a car was control arm bushings on my old 530 about 10yrs ago. Not sure I want to tackle this by myself, I'd hate to start and not be able to complete it. We'll see, it's fine for now.

[Starter986]

Originally Posted by Jasper7821

Thank you, last real work I did on a car was control arm bushings on my old 530 about 10yrs ago. Not sure I want to tackle this by myself, I'd hate to start and not be able to complete it. We'll see, it's fine for now.

Go for it. If you can't complete it... and you have to take it to a shop, well... there you are.

[Jasper7821]

Originally Posted by Starter986

Go for it. If you can't complete it... and you have to take it to a shop, well... there you are.

First thing I did was change the brake light switch cause the car had no brake lights. That was easy except for how limber your body has to be to get to the switch.
Next I’m going to tackle the “window won’t drop” trick with cable ties or bicycle adjuster. If that goes well, maybe then I’ll try the track arm link.

[tonythetiger]

Originally Posted by Jasper7821

First thing I did was change the brake light switch cause the car had no brake lights. That was easy except for how limber your body has to be to get to the switch.
Next I’m going to tackle the “window won’t drop” trick with cable ties or bicycle adjuster. If that goes well, maybe then I’ll try the track arm link.

sincere advice on this is once you go to the trouble of accessing the regulator, best to just change it out. The ball bearing regulators work better also. Remember to make sure you don't disconnect the airbags before disconnecting the battery or reconnect the battery without having the airbags connected. :+)

[Jasper7821]

Originally Posted by tonythetiger

sincere advice on this is once you go to the trouble of accessing the regulator, best to just change it out. The ball bearing regulators work better also. Remember to make sure you don't disconnect the airbags before disconnecting the battery or reconnect the battery without having the airbags connected. :+)

Thank you 😉

[Qingdao]

Surprised nobody has recommended sway bar endlinks.

Easy to diagnose. Just grab the spherical joints on both the bar end and the strut end and shake them. If there is play in the joints... there's your noise.

[Starter986]

Originally Posted by Jasper7821

First thing I did was change the brake light switch cause the car had no brake lights. That was easy except for how limber your body has to be to get to the switch.
Next I’m going to tackle the “window won’t drop” trick with cable ties or bicycle adjuster. If that goes well, maybe then I’ll try the track arm link.

I'll put my 5'/100lb wife in charge of the ignition switch. My hands are like mittens when it comes to those tight spots.

Good luck on the windows and... Tony's advice sounds good: "...once you go to the trouble of accessing the regulator, best to just change it out.". I know I'll consider that if ever I have to check out regulators.

Good luck!

[Jasper7821]

Originally Posted by Qingdao

Surprised nobody has recommended sway bar endlinks.

Easy to diagnose. Just grab the spherical joints on both the bar end and the strut end and shake them. If there is play in the joints... there's your noise.

Thank you, I'll try that too.

[Jasper7821]

Originally Posted by Starter986

I'll put my 5'/100lb wife in charge of the ignition switch. My hands are like mittens when it comes to those tight spots.

Good luck on the windows and... Tony's advice sounds good: "...once you go to the trouble of accessing the regulator, best to just change it out.". I know I'll consider that if ever I have to check out regulators.

Good luck!

Ya, I had to go to the chiropractor after changing the brake light switch.
We'll see about the regulator, from watching some videos it doesn't seem all that bad. And several people have said it's been a long time since they did the cable tie or adjuster and the window still works just fine. So we'll see.