Hiya guys, found this website when looking for a couple of solutions to various issues with my W210. I had what sounds like the same thing recently, the gears would occasionally slip and it was taking an age to change gears from one to the next.

It was making me crazy but I have just had the car back from a Merc Specialist here (I'm in the U.K!!) and it was due to a leaky seal in the gearbox (I'll find out the exact solution). Apparently it's a common issue with automatic Mercs and the part was only a few quid (£'s). All right as rain now, changing gears with ease every time.

If the gears aren't changing up or down when they should or are just simply failing to engage at all, then it could be down to the reduced oil pressure caused by leaking oil in the gearbox. Get the gearbox dipped and I think you'll find that it's low, get it sorted soon though as otherwise it'll burn out your gearbox!!!

It cost me £90 including parts, oil and labour so not a big job but it would have cost me £3000 if the gearbox had burnt out!!!

I'll pm you this too to make sure you get it!!!.