flex disc position - PeachParts Mercedes-Benz Forum

marinos90209 · #1 08-21-2010, 02:39 AM

Hello everybody,about to replace the flex disc on my 1989 300 se,question ??
the marking on the flex disc must face toward the front or the rear of the car ??

thanks for your help

Marino

Gilly · #2 08-21-2010, 04:52 AM

It is spelled out in German, I went to a translation site and I think it says "front" in German. Look on the disc and doublecheck or just put on this post what it says. "Front" in German is "Vorderseite", isn't that what it says? If that's what it says, the side that says that faces the transmission.
Gilly

pawoSD · #3 08-21-2010, 09:46 AM

Indeed, if you bought a good made in germany example, it will say Vorderseite on the front-facing side.

If it is not a made in germany example, I'd toss it out.

david s poole · #4 08-21-2010, 04:40 PM

good rule of thumb is the side of the disc with writing on it faces the driveshaft.

Gilly · #5 08-21-2010, 09:35 PM

The side with the wrting on it usually says "Vorderseite", which is "front", it faces the transmission, not the driveshaft.
Gilly

Ferdman · #6 08-22-2010, 04:59 AM

Gilly, please explain the importance of the flex disc orientation. An aftermarket flex disc I have seen looks identical on both sides so it wouldn't seem to matter which way it was installed.

Gilly · #7 08-22-2010, 04:15 PM

Be sure not to confuse a flex disc, which is usually on just the front, with a rubber coupler, which is usually on the back (there are variations though, on some cars).
The flex disc is the one designed to absorb driveline shocks, the rear one is just a chunk of rubber that looks like a flex disc.

If you look at a new one, where the metal parts are molded in that the bolts go through, you'll notice the metal parts aren't exactly centered in the rubber. I can't remember which way they are offset, but they are offset. On one side it will absorb a bit more than the other (I would assume more cushioning when enaged in drive?). Anyways, it's not symetrical, it is directional, although it can be fit either way. You can equate it to a directional tire, I guess. It will mount either way but only one way is correct. Why they can't put "front" on there in a few different languages in beyond me, would seem like an easy thing to do. Or just put it on the flex disc in paint instead of casting it into the rubber mold?

Gilly