What lubricant did they put in the trans?

The spec for my '88 five-speed is Type A Suffix A ATF. That's the old original GM ATF that has a small dose of whale oil to prevent clutch chatter and hasn't been available in this country since the early seventies!

An acceptable alternative should be the current Dexron III. Mercedes also lists 20W non-detergent motor oil as an alternative, but I wouldn't recommend it unless you live in a tropical climate.

I use Redline MTL, which is a specially formulated synthetic base 70W-75 GL 4 gear oil designed for boxes that specify ATF.

Duke