flex disk issue?
 

car is a 1990 190E 2.6 auto with about 100k.

I've noticed this for sometimes now, probably back a year, but now have taken considerable notice of it. here is the deal. the car will creak when I shift into R or into D, and sometimes from P to D the car will make a "push" forward with an audible sound. the creaking sound is like metal to metal (like creaky door hinges), and it's more noticeable in the morning and especially when shifting to R. the sound doesn't seem to happen often after the car has been driven or "warmed." do I need to replace the flex disk? how much will that service cost? thanks.

I have the same fealing but a bit different simptom.Mine does it when is warm and whith the A/C on an when I shift R to D

You're going to have to get under the car & see for yourself.

Whaaaaat.......get under the car ?
That's why i bought a Top Sider.
:D

Manny,
That is one of the drawbacks of a top sider. You never get a chance to look around under your car to spot that cracked A frame that is about to break on the highway. :D

Peter

I was just kidding.
I love looking at the underside of my car.
;)

Check engine and transmission mounts while under there. The engine mounts can be seen from up top, but the tranny mount is buried.

Engine mounts must show at least an inch between the lip of the metal top half and the frame, with the trapezoidal steel insert visible. If squashed flat, it's replacment time. Right side is easy on the gasser, left is a pain (you will probably have to jack the engine up to reach it it's so flat). 17 or 19 mm bolt on top, 8mm allen on the bottom. Be carefull starting the lower bolt, as it can fall into the crossmember and is a pure pain to fish back out.

Tranny mount, if bad, will be mushy. They are fairly firm when new.

Flex disk, if bad, will have the driveshaft end bolts off-center in the holes. It will be obvious when you look at it.

Cost for a new flex disk on Fastlane is about $90, comes with new bolts. Not a bad job if a pain in the sitting part. A very small pipe wrench works nicely to remove the allen head bolts if they are stripped like mine were.

Peter

The Mercedes drive line is considerably more complicated than the typical driveshaft with a Hook joint at either end. It's one reason why these cars are so smooth, but complexity can bring increased repairs as components begin to degrade.

The front flex disk is the number one suspect when there is excessive "driveline slop", and any with over 60K miles is automatically suspect.

The only way to verify the condition of the front flex disk is to get the car in the air, get under it, and with the transmission in Park or first on a manual and the brake off, apply torque to the driveshaft in both direction with your hands, and, with the aid of a good flashlight, look for excess flex and cracks in the flex disks, particulary the front flex disk.

Duke

thanks all for all the input. today I took it to my indie shop and the tech put it on a lift and took a lot at it. he said the front is broken but it's not serious or urgent and said it can be done at the next 3k mile oil change. and in the meantime, he said I could drive it. he did mention that a failing flex disk will cause "clunking" when car upshifts or downshifts and the metallic clunk when shifting from park to R or D, especially in the morning. I said those are the symptoms that my car has, but he said I'm fine and that it can be done next time. should I heed his advice?

It's fine for around town driving, but I'd replace it before a highway trip.

You will be delighted by the smoothness afterwards!

Peter

when you say highway, do you mean freeway, over 60mph driving? I usually take the freeway. or did you mean a big long trip on the highway? thanks!

Long highway trip. However, I recommend you change it soon -- if the oil change is still a couple months off, replace the flex disk even though it will cost more, you don't want it to come apart.

That said, I put off replacing the one on the TE for a couple years, until I was planning a highway trip. New flex disk before driving 80!

Peter

I agree, replace it now. If it breaks, you will be soooo sorry, when drive shaft tries to come through the floor boards.