coopershawk

My 2002 C230K has just started making a clunking sound when shifting from Park to Drive when it is moved for the first time of the day. After it has been driven it seems to be OK. It seems to be shifting perfectly once it gets moving. Any ideas? It has about 102000 kms or 61200 miles on it.

Thanks!

Glyn M Ruck

Is it actually the tranny? I doubt it.

Check the rear transmission mounting & flex discs on the propshaft first. Also grease the propshaft spline.

coopershawk

Many thanks Glyn! Just the thought of potential transmission problems scared the hell out of me!

Khan28

Not meaning to hijack coopershawk's thread but I'm having an intermittent clunk issue as well. Upshifting and kickdowns are smooth all the time but downshifts depending the speed I'm doing can be a bit clunky. It usually happens when I let off the gas and get back on the gas lightly. I have figured out a way to work around this quirk but obviously finding a fix is far better.

I cleaned my MAF sensor, TB and changed the air filters since they were needed and weirdly enough it seemed the tranny issues were gone but they've returned a few weeks later. I have a 4MATIC with the older 5 speed unit FWIW.

There are plenty of threads on transmission issues and I'm being led to think it's the transmission conductor plate though I wish I had more concrete evidence.

Khan28

Not meaning to hijack coopershawk's thread but I'm having an intermittent clunk issue as well. Upshifting and kickdowns are smooth all the time but downshifts depending the speed I'm doing can be a bit clunky. It usually happens when I let off the gas and get back on the gas lightly. I have figured out a way to work around this quirk but obviously finding a fix is far better.

I cleaned my MAF sensor, TB and changed the air filters since they were needed and weirdly enough it seemed the tranny issues were gone but they've returned a few weeks later. I have a 4MATIC with the older 5 speed unit FWIW.

Glyn M Ruck

Clumsy driving can induce a light clunk in the propshaft/axle.The easiest way to trigger it is to accelerate hard from a stop then jump on the brakes. You catch the TC as it is locking up & the transmission does a downshift.

Once again make sure that the flex discs are OK, spline greased, centre bearing in good condition & rear CV joint boots intact & joints in good condition. There is some natural lash in the drivetrain though. This can vary from car to car even when everything is OK.

Khan28

Ahh thanks. I have to try to locate a squeaky/creaky bushing in the rear this weekend so whiles I have the car jacked up I'll inspect those items. Next MB won't be a 4MATIC, it snows here but not enough to justify the extra weight, complication and decreased fuel economy associated with the system.

I think the transfer case is on it's way out as well. I hear a rumbling sound when I turn left or right at slow speeds in D and in R but only when I reach full lock on the steering. The fluid was replaced under the powertrain warranty included in my purchase from the used car dealer I bought the car from and for a while the sound went away. It has now returned. I remember reading somewhere that the 2005 to 2007 models had wonky transfer cases. Kind of weird I have to tackle these things with only 106,000 kms on the clock.

samaritrey

Have you had/checked the bushings in the front end? on the non 4matics they seem to only last 50-75k miles before you have issues and my car when it has bad ball joints makes a rumbling sound on turns and only at slow speeds until they get really bad.

Khan28

Haven't checked the bushings in the front end yet but the sound is definitely coming from the rear. I'm not worried about the squeaking as I know it's just a bad bushing or 2 but the light rumbling at full lock is the transfer case and eventually I will have to replace it. It sounds worse if I accelerate slightly when reversing into a parking space at full lock so it's definitely mechanical. I'm sure I can squeeze at least another 20k out of the transfer case but I'm already setting aside a bit of money for the transfer case and the eventual transmission fluid flush/change that I'll have done before next summer.

samaritrey

So a clunk in the rear with a 4matic I have never heard of that it is always the front my bad.

Khan28

I forgot to mention that 2 weeks after buying the car it did come with a 3 month powertrain warranty and I did take the car back to them to inspect the noise I was hearing. They ended up taking it to an MB dealership and one of the items on the repair order was a draining, inspection and refilling of the transfer case. I believe they used like 1 quart of the appropriate fluid. The front end is quiet at all times.