Has anyone here pulled a transmission from a w140 S320?

[WANT '71 280SEL]

I am seriously considering a '94 S320 that needs a transmission. I have a friend who is an indy MB mechanic that will rebuild it for me if I R&R the tranny myself. I will do the work at my place of employment which has a lift, tranny jack, etc. Has anyone here tried pulling a transmission from a w140, particularly an S320?

Thanks
David

[wbrian63]

I've done it - no sweat. About 1.5 hours to get it out - maybe longer to get it back in. Helps a bunch if you have a purpose built tranny lift that will allow you to tilt, etc.

You will need swivel sockets to get at the bolts on top of the tranny housing, plus extensions of at least 24" in length. By that I mean a socket with the swivel part built in - can't use a socket with an added universal joint - no clearance. Pretty sure the bolts are 15mm.

The dipstick is attached in two places - through one of the mounting bolts, plus another bolt to the cylinder head.

While you've got it out, change the rear main seal on the motor. They come in a standard version and a version with an offset lip to keep the new seal from riding in the groove created by the old one. I opted for the offset lip. AllData and other sources will say you need a special seal installation tool - I did it without any issues without the tool - just follow the instructions on what bolts to tighten and in what order.

Be sure not to rotate the motor in the wrong direction while removing the torque converter bolts.

Also, examine the charging circuit harness for signs of insulation degradation, especially on the connector to the oil pressure sender. I didn't notice the flaking insulation, and had to replace the harness after getting everything back together - would have been far easier when I did the tranny, as the wires run through a conduit that crosses over the transmission from drivers to passenger side, and the conduit is held in place by 2 of the tranny-to-block attachment bolts. The harness is about $200 if I remember correctly, and super easy to replace while the transmission is out.

One thing about the harness - it connects through the floorboard on the passenger side to the interior of the car. The heat shield that covers this connection is removed from the outside of the car - despite how it looks. I found this sad fact after removing all of the junction blocks on the floorboard inside the passenger footwell to discover what looks like a captured nut on the shield - threaded onto a bolt from the inside, is actually a removable nut, threaded onto a stud welded to the body - wasted over 3 hours with that debaucle.

Other things to replace while the tranny is out - flex disks - you've got to detach them anyway to get the driveshaft loose.

[WANT '71 280SEL]

wbrian63,

Thank you very much for the detailed write-up! When you did the job did you use a shop lift or jack stands? I don't think I have any 15mm sockets with the universal joint built in. I guess I'll have to do some shopping for that one then. Thanks again,

David

[wbrian63]

In a shop with a lift. My days of lying on my back doing this kind of work are long past.

[Pete Geither]

Originally Posted by wbrian63

In a shop with a lift. My days of lying on my back doing this kind of work are long past.

That was a GREAT write up. That is what makes this site so great,,,, thanks.