Early 722.6 Experts or People who have had the problem.

[Eiknujrac]

I have a 98 C280 with the infamous 5 speed electronic tranny. I bought it at 86k WIth no records of transmission service or repair. It is now at 90k, and the other day I was pulling up to a stop sign (didnt come to a complete stop), and gave it throttle to accelerate. I'm assuming it was downshifting from 2 to 1, but it gave me a huge CLUNK like I had hit a pothole or something. Is this a standard sign of the 722.6 going bad or is this something else? It seems to only happen on the 2 to 1 downshift, and it has only happened 2 or 3 times in the past 2 weeks. I have no other signs of tranny wear, just this.

Does anyone know how many miles (rough estimate) I have left before I have to replace the tranny (assuming this is a tell-tale sign)? I baby my car and never push it hard unless it is necessary (merging etc.). I'm just asking because I have a 6 hour drive on wednesday that I have to make (flight isn't possible, i'm going to be carrying a lot of boxes/luggage) and I don't know if this is serious enoguh to the point where the car won't make it.

THanks in advance!