My Mercedes ML 2.7CD Auto appears not to want to stop ie the transmission is not "slipping" at 800 revs.All gears work fine.Any ideas

you need to change the oil in the auto box. if this dont help then the servo in the auto box is sticking.

If the transmission is slipping and I assume that is what you mean then it is going to need an overhaul. Once an auto transmission slips it is done.

my van is doing the same exact thing but the othe day it was perfectly fine no slipping i went about 25 miles and i started off from a stop the engine rev and tranny slipped and the van died i restarted the van it runs great but acts as if there is no transmisson does not take power frm ngine when shfted does nothing please help

Sounds like your transmission has come to the end of its life. You can try getting the transmission flushed , and an additive I.E. No Slip added. That might cure some of the problems but obviously if its slipping the clutchs inside are worn out and transmission needs an overhaul.

Possible torque converter going bad. The torque converter connects the engine to the transmission through the drive shaft.

Also, check that the auto transmission fluid is topped off. Low fluid can cause the symptom described, as the torque converter is filled and works with auto transmission fluid.

Good luck on this repair.

i had a mitsubishi gto wot did the same as that and had to put new auto box in had it in loads of garages but nothing they did worked not sure if same that car had recon box in wen bought it and did the same within 6 months of me gettin the car

It definitely sounds like the transmission. If you haven't had the transmission fluid and filter changed I would recommend having that done. I also recommend the Lucas transmission oil which will help alleviate (within reason) slipping issues.

Auto matic or standard ????If standard, the clutch is shot, if automatic the clutches are slipping may be low on transmission fluid, check first.

seems to me , the 3rd gear shift range is slipping.
You probably have internal failure.
You should take to transmission shop