I have searched for the information about replacement of these motor mounts on the forum, but there are a few things I'm still not clear about:

1. Do you have to loosen any part of the engine (engine shocks, for instance) aside from the old motor mounts before jacking it up?

2. Will any components of the engine be damaged by the actual lifting of it?

3. How do you go about changing the auto trans mount?

4. Is it all right for me to spray water up into the engine compartment to clean it out before the job, or would it just be better to get it prof. steam-cleaned?

5. Will I need any key allen wrenches for the job, and if so, what size?

6. Should I use one jack and a jackstand for safety in lifting the engine?

Thanks a lot for any help.

Have you done a search on "motor mounts"? This topic is covered very thoroughly in previous posts. It would be quicker than waiting for responses.

Do clean the engine compartment first. You will be glad you did. I used the Gunk in a spray can, 3 or 4 cans in all. Don't spray water around the turbo until it is cool.

__________________
1985 300SD, 203,000 miles, dark blue

Lil Sarah says: "Poor old Grandma Blue Car...She's sad."

1. Loosen the engine shocks, loosen fan shroud, disconnect accelerator linkage from firewall to engine.

2. Lift the engine slowly, make frequent checks for interference. Especially the fan.

3. Jack transmission slightly. Remove crossmember, unbolt mount. Easy.

4. Either is okay.

5. 6mm & 8mm. Allen sockets make the job a lot easier.

6. One jack is adequate. Place under the lower oil pan. Protect oil pan with piece of wood.

The job is easier if you disconnect only one mount at a time. That will prevent the engine from shifting and making it tough to get the mount bolt started. (Loosen the opposite mount, just do not disconnect completely.)

Be careful when cleaning, but it is always a good idea to clean it up before you start. Never spray cold water on the IP when it is hot, there are some delicate machined parts in there. Wait til it is cool before washing that down.
There is a vent on top of the trans, water can get in there also. not smart to rinse in that area. If you spray down the rear of the engine water will run right towards that vent.
I would get a set of allen head 3/8 drive sockets for your Benz, there are lots of those to work on as you go. You will need a couple of sizes to remove the motor mounts. There is one that requires an medium extension to reach. That one is accessed from under the engine cradle. It can be tough to loosen. I had one that I used an electric impact wrench to rattle loose. Be sure to use a little anti seize paste on the threads when reinstalled.
The trans mount is easy, either check a Haynes manual or climb under there and figure it out.
You will need to get the car up so you can work under it, always use quality jack stands to support it, or you could have an adventure you do not want to think about. You will need to raise the motor once you have the two lower bolts out from underneath. Then there are three bolts on the top of the mounts, the engine needs to be raised to get to the inside one.
The shocks usually get in the way and will need to be unbolted to get to the mounts.

My wagon has some kind of metal cover/plate over the melted motor mounts. Do I have bolts under those plates? I haven't figured out how to remove those plates, but haven't really tried yet either.

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Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Remove the center bolt from underneath. Jack up engine. Metal plate will slide out, revealing two bolts that secure the mount to the frame.

Don't be surprised if you find only two bolts.

Yes, two bolts on top. Take a look at those plates before removing them. Too easy to spend an hour trying to figure out which way they go back in.
Don't ask me why I know this.