Thanks for your comments.

Some of the hot/cold issues I described above have changed during a 400 KM trip today.

Cold this morning, no problem with reverse.

Drove 150 KM and stopped - no reverse.

Drove another 50 KM and stopped - no reverse.

Started up and drove 1 KM - reverse is back and performing like a good 'un.

Thereafter, including some scary moments in tight carparks and heavy traffic - no problems.

I have heard about this teflon seal. Can you tell me more, please?

How easy is it to replace?

My next plan is to change oil (torque converter and box) and filter, ensuring that a genuine MB filter is used. I cannot be certain that the torque converter was flushed last time or that a genuine MB filter was used. Last change was about 45 K KMS ago.

When the box was hot today, I checked the fluid level - slightly above the high mark. This on level ground with engine idling.

Another thing was that the fluid was a pale pink colour and it smelled fresh and fruity with no hint of unpleasant burning smells.

Any further comments much appreciated.

My thanks in advance to all.

RayH