I have a 1989 300SE and may need to replace the transmission. Is this as simple as with an american auto or are their any unknowns out there?

Thanks in advance.

Having never done an American car I don't know if it's easier or more difficult but my guess is that the SE takes a little longer.

You have to drop the exhaust system. It's a PITA to get to the nuts that hold the pipes to the exhaust manifold. While the pipes are off, replace the steering idler arm bushings.

You have to drop the exhaust to remove the cover plate that hides the drive shaft. You have to get to the drive shaft to move it back so you can put back the transmission. It's possible to remove the transmission without shifting the driveshaft. I couldn't fake it the other way. Consider new driveshaft carrier bearings/bushings while the driveshaft is accessible.

The flywheel to torque converter bolts require creative use of sockets and extensions because the drag link is right there.

Block the engine well because it won't balance on just the front mounts and you'll upset the radiator, fan, fuel lines and throttle linkage if it tips back too far.

Everything else is pretty conventional. Wouldn't do it without a shop manual for reference even if the shop manual available from MB doesn't cover transmission R&R specifically.

Little things you'll need are washers for the various transmission fluid lines, an o-ring for the dipstick tube and new bushings for the shift rod.

Sixto
91 300SE
87 300SDL
83 300SD