Flex Disk Condition?
 

How does this flex disk look? Normal? Replace soon? Replace now!? Thanks.

Not normal, see the cracks?

I'd go with "soon".

THAT is not a flex disc, that's a rubber coupler, there's a difference and yes I'm serious. Yes it should be replaced because of the cracks.
Gilly

Part number 124 411 02 15, Drive Shaft Flex Joint, AKA flex disc[sic]. With those cracks you should replace it as soon as you can.

sorry to hijack, but what are some of the early problems that could occur with a crack-"ing" flexdisk?

The flex disc is usually but not always just up front (there are a few that have them in the back). The flex disc has the sections around the bolts that absorb vibration. The "solid" ones like this are called a rubber coupler. I've seen the rear ones crack like this or have pieces of reinforcement (like a heavy string) shredding out to the sides.
The flex disc is a wear item and should be inspected occasionally. The rubber coupler can fail, so good to keep an eye on it, but is intended to last the life of the car, unlike the flex disc. Description is wrong in the part number that was quoted, nothing new, the parts dept does use different sounding descriptions for things, and as far as that goes everyone uses different terminology for things, as long as everyone understands what's being discussed, then we're communicating, right? But a flex disc is a very specific thing, usually you only have 1 flex disc and it's up on the transmission side.
Gilly

Drop the $40-60 and replace it.

flex disc
 

gilly,i think the industry uses flex plate for the trans and flex disc for the drive shaft.

You may hear a thunk-thunk-thunk from under the car under hard acceleration. These are not alot of fun to switch out because they are under the car, but if it is thunking, you should change it. If that photo is of your flex-disc,:eek: order a new one today.

What he said...

There was a person in another Benz site whose flex discs went out on her 300E.

Due to their location if the flex disc goes out while the car is in motion it may cause deployment of the ari bag.

That's a very expensive repair. In my opinion flex discs should be changed, as a matter of course, every so many miles. It is not an expensive reapir and not only does it make the car run smoother (no thunk thunk) but it can also prevent a major repair down the line.

Cheap insurance.

What is the difference between the rear rubber coupler that Mercedes dealers sell and the aftermarket ones that are available for less than half as much?

The aftermarket ones are Lemforder or Febi. The one at the dealer did not have any marking that indicated manufacturer. I did note that ones at the dealer appeared to have 12mm bolts whereas the ones on my 124s have 10mm bolts; I think the bolt size will not affect application.

The updated part number I used is 1294100015.

Edited:
From photos on Fastlane website I think the one at dealer was a Lemforder.

Thanks everyone. I'll get it changed as soon as possible. Gilly, and everyone: how many of these rubber couplers are there on the 96 c280. I've heard there are 2? Are they the same part #? Thanks.

Just the rear one should be the rubber coupler like you showed a picture of. The FRONT one is the "flex disc" and should be a different part number, looks a bit different but installs the same way. One thing to remember is that the differential in these cars is bolted to the rear of the car, independent rear suspension. The driveshaft does not change angle, it's all in a constant angle.
Gilly

Gilly,

I believe that is the front one. It was pretty close to the transmission? Is that right?

I also saw a post that someone believed Lemforder was better than Febi? Anyone have their own experiences?

Will a new flex disc soften the gear shifts? 1-2 still jolts even when i back out the modulator adjustment all the way.