Factory spec is for 1.9 quarts of 5W-20 engine oil. Use any good synthetic and you'll be fine.
The MB manual tranny came from the factory as a notchy shifting unit, particularly the 1st to 2nd gear throw, and no oil will dramatically improve this design flaw (ask me how I know...)

Some prior threads on this topic below:
https://www.crossfireforum.org/forum...smission+fluid

https://www.crossfireforum.org/forum...=owners+manual