I've just bought two old Mercs, an 81' 300D and an 83' 300D Turbo.
Both have failing Transmissions (Automatics).
They have to be reved very high, or for 10 seconds with a steady rev in order to change into gear. The old one is now parked as it was getting imppossible, and the newer is just starting to go.
IS THIS THE MODULATOR ???
IF SO HOW DO I REPAIR, COST, Should The Part Be New , Will I need any specialized tools to fix this ? I have the kindergarten set, which has severed me so far.

Thanks for your time and thoughts

-Pat