My 1989 update W124 260e has developed an intermittent fault in the transmission.

When cold car will reverse no problems. When hot car starts in reverse but suddenly stops as if handbrake is on.

All forward speeds no problem. Changes smoothly.

Have changed filter and fluid. On inspection of the filter it was full of "sludge" - No apparent solid pieces of metal

Any ideas? Up for rebuild? Clutches? easy or difficult repair? can DYI or shop job $$$?

heres some fotos







Picture of transmission