240 DL Sedan, 150K miles

The cars makes all types of creaking noises, so I’m not sure how long this *problem* has existed.

Basically, I here a single clunk every time I apply the brakes regardless of speed. The clunk does not continue as long as I don’t take my foot off the brake. And the car does not pull to one side or another while braking.

If I pumped the brakes, I would get the clunk every time I hit the brake peddle. Yet it does not happen if the brake peddle is hit when the car is at rest.

I also just noticed that it did not seem to happen when I backed up in a parking lot. Curious I went to a safe area of the parking lot and experimented. If I went forward and put the car in neutral, then the clunk occurred, as expected, every time I hit the brake peddle.

However, if I go backward, put the car in neutral and coasted, then it sometimes happened on the first tap of the brake peddle, but did not happen on subsequent taps on the brake peddle.

I tried this a few times just to assure the above was correct.

It’s unclear where the noise is coming from. It sounds like the rear, but then again possible the front.

The front brakes, rotors, calipers are all new, the rear brake pads are old, but good.

Any thoughts on what might be causing this clunk?

 

Trailing arm bushings, panhard bushings and/or torque rod bushings.

 

Thanks, I'll check them this week.

Other than the noticeable clunk I hear, the car rides and tracks ok. Is this (replacement of trailing arm bushings, panhard bushings and/or torque rod bushings) something I can wait until the spring to do (i.e. warmer weather), or is it a safety issue that needs to be addressed now?

thanks

 

Well, probably 90% of 240's on the road have bad rear bushings. It's annoying and eventually will cause issues when it's metal to metal but not in the short term.

 

I am having the same problem. how many bushings are needed?

 

It depends on the car. The way to check bushings that aren't visibly torn or rotten is to put the car on a rack or jack stands and take a pry bar and wiggle them. Slop bad enough to generate a clunk is usually pretty visible. These cars are now 18-36 years old. My thinking is if one is bad, they're all on their way out. With that in mind, on my wagon, I bought the complete rear bushing kit from IPD. I bought rubber rather than poly because I figure if the o.e. lasted 20 years that was good enough for me.
http://www.ipdusa.com/version.asp?st...=265&V_ID=1665
The trailing arms are usually the culprit. Two bushings per arm, two arms. The smaller forward ones are easy...the rear ones are a real pain sometimes when on the car. The panhard rod runs from side to side attaching to the axle and body, so 2 bushings there. There are 2 torque rods, 2 bushings each. Those are all pretty straight forward also. By buying the entire set, I had all the bushings on hand before I even got under the car. That way, I was able to do the entire job when I found ones that were questionable rather than leave 'em and put it all together again. Still, if you find ones that are obvious culprits; center metal is shiny from contact...then you can just buy specific bushings if time and money are an issue.

 

thanks for the info and the link!

 

The left front of my 940 wagon does the same thing. I think it is in the strut. When I changed the ball joint that whole strut tower moved out way too easy.

 

Hey...I just found out a couple of months ago that the Rathskellar closed down! That's just wrong!! They should have been tax exempt! That was the best place in town for cold beer and cheap steaks!

 

yea!

Bump

 

Took the car to my mechanic this am. The sound was easily reproducible; he thought it was coming from the front end.

On the initial pass, there were no loose bolts, and all front end bushings looked ok. When his partner got in the car on the lift and hit the brakes while he spun the tire, we could see the new brake pads moving slightly in the rebuilt calipers. That might be the problem, but it wasn't.

On closer inspection, though the caliper bolts were tight, we could see the right caliper moving around the bolt when he would rock the wheel back and forth with some pressure on the brakes.

He tool the caliper bolt out; it looked ok, though the last few threads were clean. He felt the bolt was not bottoming out (I think I go that correct). The threads on the inside of the caliper looked ok, so he took a tap and cleaned out the caliper threads. He did the same for the other caliper bolts on both sides.

Reinstalled the bolts and success, the noise is gone.

He also noted it was a good thing that I had this checked. The bolt could have over time sheered off and caused more problems.

He noted that the slight play in the brake pads in the caliper was ok; that there was just more space around the edges of the brake pads where they slip into the calipers probably due to the manufacturer cleaning rust off the original calipers. He did suggest some fixes for this, but it did not seem worth the effort from the conversation.

As an aside, I also noted to him that there was lots of clunks from the rear going over bumpy roads; lots of those in NE. Turns out the torque rod bushings need to be replaced on both sides. I will get this replaced with rubber bushings which he felt hold up better in NE than the poly bushings.

I'd do this myself, but getting too cold and just not enough hours in the day right now.

Thanks for the help from all.