Hi everyone

Patient is 2001 CLK 430 with automagic transmission. It has about 155 000 miles.

For some time I notice occasional strange shifting behavior from say, a stop sign (braking then accelerating at 5 mph). Also 1-2 sometimes is odd if you let off the pedal.

But the past couple days noticed something quite odd. Past month I drove only in "W"-mode (starts in 2nd gear). Now not so much ice so put in normal "S" mode.

a few times when car is warm, crusing steady normal speed on the highway to work, will downshift to 4th gear from 5th on its own. Shift itself is very smooth, only notice the tacho jump up from 2750-ish RPM to 3600-ish RPM. Exactly like if you slapped stick to the Honecker direction (it is valid comparison as the extra gas burning is similar). I didn't move my foot at all and normally the car at this speed doesn't give you a shift as you can accelerate quite fast at this speeds (or rather I don't try to shred license by using so much foot, not in this country)

But, if I flip switch back to "W", shifts nice and back to 5th gear and normal engine speed. Exactly as if slapped stick right.

But I can't get gear back by moving stick in "S", but I can downshift some more.

I don't know what the "range" is as of course this small LCD display is broken on my car.

Anyone see similar issues before? I think to check oil, but alas dipstick missing. Does anyone have length of dipstick? I would \pick one from scrap Mercedes in j-y but probably it would be a 190 or W124.

Thanks in advance for any suggestions