Hello all!

I'm having yet another flex disc (?) issue.

My problems started, I would say, about 3 years ago when an old flex disc (the one directly behind the tranny) got all busted. No problem, I thought, as I cannot even recall the last time it was replaced, or if it had been replaced at all. A year or so however after the replacing it, the "new" flex disc got busted again! This time, some of the tranny links were damaged. So okay, maybe it was a simple fluke or an unidentified parts problem.

Just the other day however, I would say less than two years with the replaced flex disc, I felt that familiar vibration again. I had the car raised up in a gas station and saw that, yep, the flex disc is torn up again! This time, it wasn't totally obliterated though which is why I was still able to bring it home.

So here I am not knowing where to begin. I'm sure flex discs should last longer than what I experienced! All I do is city driving though there are times when I do mountain driving as well. I drive quite fast/hard but not enough make any burnouts (not even possible I suppose with a 123 240D). Just enough to keep the engine in good, diesel-ran condition.

I'm sure I used the correct, OEM parts. What about tightening the bolts? I've read somewhere here that the bolts are not supposed to be over-tightened (?), about 1/4 turn after hand-tightening the nuts. Is this right? The reason supposedly is to allow for minute adjustments as the car runs as the driveline should be expected NOT to be perfectly aligned or balanced for its age. Could using a lower ratio differential (from 300D) have that much effect? If that's so, then why is my clutch (manual tranny) still tops? Shouldn't that be the one to give in first?

BTW, I had my exhaust pipes checked about half a year ago and I specifically do not remember seeing problems or signs of wear and tear with the flex disc then! The other disc, the one nearer to the differential, still looks good as none of its threads are showing.

Im sorry for the exasperating thread. All help will be very much appreciated.

BTW, the car is a '78 123 240D.

Thanks!