1983 300SD - It is time to change the motor mounts. Can anyone advise me on some hints to make the job easier. My main concern is how far and where to jack up the motor to get the old one out and the new ones in. What has to be disconnected?

Disconnect the accellerator linkage (longitudinal shaft) at the firewall. Disconnect the lower end of the engine shock mounts.
Jack the engine from under the lower oil pan. Place a board between jack and oil pan. Raise the engine just enough to move the mount.
Loosen both mounts, but only disconnect one at a time. That will prevent the engine from shifting excessively.
If you are using a Haynes Manual, the torque value for the large mount bolt is incorrect. You will likely strip the threads if you use their figure. MB specifies 70Nm for the large bolt.

Thank you so much. Sounds like I would have had some problems if I was to try it for the first time on the fly. Dennis

I have just changed mine in a 82 300sd. If you have the access, I would jack the car up on jack stands or run it up a ramp, I had a come a long hooked in the rafters of my garage and lifted engine that way. Getting car up on jack stands makes it easier on fat guys like me to get the bolts from underneath. Use a 8mm hex driver with an extention on bottom bolts and I believe 6mm on the two tops. You will have to use extentions and a swivel for these makes job a lot easier, and some advise I hear all the time on here check the hea shields and make sure they go back on this will save your mounts from oil and other junk. Good Luck

I just did mine in an '85 300D. It sucked. Very frustrating until my neighbor introduced me to wobble (not u-joint!) sockets. Apparently you can usually find them in pawn shops.

Take your time, jack the engine up, use extensions and wobble bits for those hateful little 6mm allen bolts, and when you go to put the big bolts in from the bottom, use a prybar between the crossmember and the oil pan to move the engine a tiny bit. When it's all lined up, the bolts will just thread right in.

Tools required:

• 6mm and 8mm allen sockets
• floor jack or engine crane/hoist
• 7mm, 8mm, 10mm, 12mm(?) open-end wrenches
• 10mm, 12mm sockets
• various extensions and wobble bits
• prybar

Oh, and wear coveralls, safety glasses (or a face shield), and expect to degrease all the way past your elbows when you're done.

__________________
Currently converting a 1984 Toyota Land Cruiser FJ60 to use a 1985 300D engine and tranny... Engine/tranny are in, no transfer case or wiring yet.

My comments are based solely on my experience which is limited to one car one time engine mount replacement. Good luck. This is a great DIY job.

I jacked my engine from below using a wooden "pad" and the oil pan as a jack point. I reccomend removing the fan shroud clips so the fan will not cram itself into the shroud. I also would monitor the progress of the jacking to avoid pinching, crimping, or other wise damaging hoses, wires, and steel piping (for coolant) that is located at the center of the firewall (this stuff can get crushed/pinched if your are too exuberant.

use a toothpick or similar high tech device to pick debris from the allen heads prior to inserting the allen wrench (for the big bolts from below and more likely the top 4 bolts that hold the mount to the car.) Having a partially crudded plugged fastener head will only promote the opportunity for stripping the head of the fastener.

Rob M

__________________
Rob M
Norwich, VT USA
1980 240D Euro delivery 4 speed manual silver/blue
~160K miles

do one side at a time too increase the ease at lining things up...A hockey stick work well to coax the engine into position for re-installing the bottom bolts....

__________________
Rob M
Norwich, VT USA
1980 240D Euro delivery 4 speed manual silver/blue
~160K miles