I am in the process of removing the engine (M116) from my 1982 380 SL. The Mercedes manual suggests that the engine and transmission be removed as a unit. As I began it seemed to me it would be just as much work to go by the manual as it would be to remove the transmission first and then remove the engine. I was going to have to seperate the two at some point and I didn't relish plucking the combined two out of there. I was worried about having enough clearance between the front of the engine and the ac condensor if I left the transmission in. While I did some steps that will move me closer to pulling the engine they would not have been necessary if I just wanted to remove the transmission so I will not include them here.
So what follows is what might be called "Removing the transmission from your 380SL in less than 30 steps".
1. Remove air cleaner
2. Remove spark plugs
3. Remove the hood (bonnet)
4. Remove the exhaust system (only four bolts about 5/16" make the attachment to the exhaust manifold and if they give you any trouble don't worry about breaking them as they are bolts with nuts and not studs (good idea!)
5. Drain transmission
6. Remove flexplate access cover plate.
7. Remove tierod end and steering dampner (this may not have been necessary but probably made the process easier. I was able to luck out and press the tierod end out with a Cclamp)
8. Detach transmission cooling line passenger's side (at transmission)
9. Remove dipstick and housing from transmission
10. Remove oilfilter
11. Detach transmission cooling line driver's side
12. Remove starter (the one tool I needed and didn't have was a 3/8 drive 10 mm allen wrench and it is required to remove the starter)
13. Remove the transmission "skid" plates (2) from under the transmission (you should support the transmission before removing these)
14. Remove the top two bellhousing bolts. (this was expected to be a little tight and it was... a 17 mm 6 point on a universal followed by a 36" and a 12" extension). I removed the two top bolts at this point knowing that if I couldn't get those out I wasn't going to get the transmission out
15. Detach the three electrical connections on the transmission: the larger one has a rotating slide to "unlock" it. Another is held in place with a bolt with a 10mm head and the third is a ground wire held in place with a phillips head screw
16. Detach the vacuum line. I decided to remove it at the back of the manifold rather than on the transmission. A little care would be needed when actually seperating the engine and transmission if it were removed from the transmission (the line could be bent or damaged)
17. Remove the brake booster vacuum line
18. Remove the kickdown cable from the throttle linkage
19. Remove the six bolts (13mm head) that hold the torque converter to the flexplate. Leave the three 10mm head bolts in place as they hold the ring gear to the flexplate
20. Detach driveshaft from "rubber doughnut" and then remove the rubber doughnut from the output shaft
21. Remove the plate from the "second starter" opening. This was a mystery to me. Are the right hand cars equipped with a starter on what Americans call our driver's side??
22.Remove the spacer plate that is between the starter and the bellhousing- pull it off of the pin that holds it in place
23. Detach shift linkage from transmission
24. Use additional jacks and blocking to support the engine
25. Move transmission jack into position under the transmission. I have one of those cheapos from Harbor Freight that works great for all the more I have to use it
26. Remove the six remaining bellhousing bolts
27. Seperate transmission from engine
28. Make sure the torque converter remains in place and lower/remove transmission
29. Enjoy a Guinness (or two)