This is not normal for your transmission. I have a 2001 S430 and I barely feel upshifts. Downshifts are almost non-existent.

My car did this once, as I was coming off an off-ramp from a 30 mile drive home from work. Didn't do it the next day until exactly the same time (after the drive, on the same off-ramp)

I took it to a friend of mine. The car had 180,000km on it (110,000 miles approximately).

He found that the transmission fluid was very very slightly low. He said on a normal car people would consider it normal and drive it, but these transmissions are very sensitive. He also found that the transmission oil was BLACK as it was original.

He flushed the transmission and the weirdness went away completely. I have now put another 70,000km on the car (42,000 mi) and it has never done it again.

Check very carefully the transmission oil level (using the MB special tool dipstick and either a DAS laptop or an infrared thermometer aimed ad the transmission pan) There is a specific MB procedure for this which you must follow exactly.

Check the colour and smell of the fluid. If anything looks wrong, change it.

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