Transmission -- '97 C230

[Benzadmiral]

Hello, all,

I've done a search, and what I've found applies only partly to what I'm experiencing.

Four times this past week, my '97 C230's transmission has balked at shifting into a higher gear. This *only* happens:
1) on the first shift after the car has been started (not always from completely cold, either)
2) under a set of conditions which might have "confused" the electronics. The first two times, I'd shifted from R to D without pausing a second or so for D to engage (no, I don't normally do that; I know it'll shorten a transmission's life). Wednesday evening and this morning, I pulled from a parking slot into traffic and had to alternately push on and let up on the gas once or twice -- then when I accelerated, the transmission stuck in a lower gear and wouldn't upshift, running the engine up to 3000 rpm. I pulled over, shifted up into P and back down to D, and everything was fine for the rest of the drive. Perhaps it "thought" it should stay in a lower gear?

Now I know the transmission was designed to delay the shifts when the engine is cold, to warm up things faster. And the car has always done that. This is new.

I searched here, in fact, before I bought the car last year, and was aware of the transmission issues. One of the things that convinced me to buy the little gold beast was a warranty service record from the dealer; the previous owner had had some transmission work done. I don't have the records here, and can't remember exactly what was done or the mileage. I'll look it up when I get home.

How long would M-B warranty that work? Years or miles? Or would it be one of those sneaky "as long as you own the car" deals, so it wouldn't apply to me?

Is it necessary to go to the dealer for this, or could an independent handle it?

I know from my search that it could be low transmission fluid, and if this were an earlier model car I'd have checked it already. But I'm worried about checking it myself and possibly overfilling, since I have no way to check the fluid temperature.

Any suggestions would be welcome!