PeachParts Mercedes-Benz Forum - View Single Post - How to change front subframe mounts on a 380SL?

psfred · #5 06-19-2005, 01:28 PM

There are two rubber mounts on each side of the R107 subframe (same as on the W114/115 which shares the part, I believe).

The subframe mounts are oval, about 1.5" wide and 2.5" long, one in front and one behind the spring. The other "mount" on there has the engine sitting on it....

If the mount bolts stick out from under the subframe, the mounts are flat for sure. Should be an inch or so of mount visible above the frame, too. Likely, unless replaced yours are quite flat.

Replacement is similar to the W115, which I have done:

Jack up and support FRAME (not subframe) on jackstands. You can do just the front or front and rear, whichever is easier for you.

Remove engine shocks (front of engine on the accessories brackets, I think)

Put a floor jack under the engine pan, padded so that it won't damage the pan, or you can use an engine hoist attached to the top if you prefer.

Lift engine and remove the subframe bolts on one side. Watch for the nut plate breaking (at least on the W114/115 chassis, not sure what they bolt to on the R107).

Pull bolts out, then lower engine/subframe assembly until you can remove the mounts upward from the subframe. Spray new ones with silicone lub or spread some undiluted dishwashing detergent on them, and put them in place, then raise subframe and install bolts. You may have to press some to get the mounts into their pockets. Leave the bolts loose, but screwed most of the way up, until you have both sets in.

If the subframes does not drop far enough, you must pry between the top spring cup and the frame to force it down. Usually necesary only on the second side.

Repeat for the other side. You will almost certainly have to pry this side down -- you need a bar or pip about 3 ft long, maybe more. Have a care to keep fingers out of pinch points.

Tighten bolts and replace engine shocks.

Note that if the subframe mounts were bad, the engine mounts are too, and the fan will now probably rattle on the fan shroud or other signs of flat mounts will appear as you lower the engine in the body. My 220D started banging the AC compressor on the fender when I replace the subframe mounts, quite a surprise. I'd get the engine mounts and do the whole thing at once.

If you have the appropriate tools, you can suspend the engine and drop the subframe down separate (if you are doing the engine mounts this will work better anyway). Watch for strain on the brake lines if you do this.

Peter

Best to have a helper on this job -- watch for engine clearance as you drop the subframe, this isn't a problem on the W115 but the W107 with the V8 is more complicated.