Early 722.6 Experts or People who have had the problem.
 

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!

Ah the trip got bumped to tommorow morning... Anyone?

lol, search for posts under my username and 722.6. I'm at 92k on a 97, which is luckily under warranty. Does it slam into gears when upshifting, or is this slippage before even shifting into gear? Either way, there are a lot of variables. Could be total replacement, TCM, conductor place, valve body - there were a LOT of updates for this trans. The very least I would do is take it to a reputable indie and get the codes read. At 90k, if nothing else is wrong, I would absolutely do a fluid and filter change.

For many manufacturers the early five speeds have a tendency to hit first gear hard.

Do a search, and think about maintenance of the trans; fluid, filter maybe a magnet.

Since the trans is computer controlled & ADAPTATION information is available, have the trans ECU scanned for codes & see what long term adaptation torque figures are!