Hi, thanks for that - I asked the question because if the drain plug ISNT there... I'll probably need to do 2-3 changes... and as costly as THAT is, I may not have much choice.

Obviously, the more changes I do the better, but how little "contamination" does it take to ruin the rest of the fluid? It seems to have happened once by changing 3 litres.... next time I'll change more - but there will still be an element of contaminated fluid.

Its almost like a virus... I honestly thought I was cured first time.... and why on earth does it only affect the TQ lockup?

No one seems to have heard of this at MB UK dealerships... on C class rad faiures resulting in similar symptoms (but not the cause in this case)

Thanks

Mike