107 Engine Mount Replacement

[ctaylor738]

I am about 95% done with this job on my 560, so I thought I would share the experience while it is still fresh in my mind.

First of all, it is a miseable job, and probably best left to a shop. But if you have to try it yourself, here is my .02.

Put car up on ramps. and remove large engine mount bolts from below. Unclip fan shroud and pull up. Put jack/wood block under oil pan and raise front of engine until engine butts up against firewall.

Right side. Drain the radiator so that you can remove the coolant reservoir. Puill the shock mount bracket loose, and remove the heat shield. Then the bolts that hold the motor mounts to the frame can be removed from above if you have a 1/4" ratchet and 6mm hex bit socket. Remove the old mount and install the new one, noting that the right side has two white dots.

Left side. Reach in under the power steering hoses and remove the bolts with the ratchet. You need a really short hex bit - you may have to grind one to get it to fit. Remove old mount and install new one (one white dot).

Drop the engine down in stages. noting the fit in the slots in the new mounts. Most likely, the engine will have shifted toward the rear, so grab the PS pump and the cruise control, and give it a a yank forward. Lower a little more and yank forward or to the side as needed, looking at the left side mount for alignment.

Re-install large bolts, re-fasten fan shroud. re-install overflow tank. Enjoy lack of vibration!

Note - do not attempt this if you have large hands - very limited clearance. You also need some strength, as you will need to remove the bolts holding the mounts to the subframe with a small ratchet with very little leverage.

All in all, a good one to farm out.

Also attaching a picture of and new and old mount.

[Roncallo]

I have found the exhaust manifolds so easy to remove on these cars that, I just pull them to do the job. It also gives you a good opertunity to clean up down there.

John Roncallo

[ctaylor738]

I was very close to that, especially with the rear bolt on the left mount. But I was able to jack the engine up a little more, and filed down my 6 mm hex bit socket about 1/8" and was able to get that and my ratchet to fit.

[Benzmeister]

a user friendly place to do jobs top side anyway. But your description of changing engine mounts is about the same for most cars and is not a pretty job. My son had to change mounts on his Intregra. He is a DIY type, but he left the mounts to a shop to do. Proper equipment is the key also. I tried one of the engine vibration dampers and it was the hardest job so far as far as space to do things. Going the change the other side this weekend and the valve cover gaskets, which if no one has done it, on a mercedes 450SL or SLC is a snap. They are rubber with a lip and the lip fits into the cover. 4 bolts hold each cover, no torque specs just tighten until they are tight.

[Steve Gutman]

There is a torque spec for the valve covers and it is something like 7 nm. I can look it up if necessary. If you over torque them you could have negative results. The job is very easy.

My motor mounts were both broken in two. Since I replaced the lower ball joints, a-arm bushings, and sub frame bushings the motor mounts were more exposed. It was still a bite and now I have 3 sizes of 6mm hex stock I cut from a allen wrench. The rear ones are pretty burried. The biggest change in handling came from changing the rear sub frame bushings and differential mount. It was like a different car.

[Steve Gutman]

Broken on left, New on right.

[jdhill]

And you bent 8 folks wonder why we love our inline 6's. As a sidenote, we rebuilt the entire front suspension in our 75, 280 by removing the engine and transmission. Took my son and I less than 2 hours to take it out, makes everything else easy. Sometimes what seems like the long way isn't.

[Strife]

Originally Posted by Steve Gutman

There is a torque spec for the valve covers and it is something like 7 nm. I can look it up if necessary. If you over torque them you could have negative results. The job is very easy.

I second this. The valve covers are very thin castings and warp (permanently) very easily. The small crush washers should be replaced also - prices vary wildly for these, ranging from $0.08 (about what they are worth) to $1.00!!!

[Steve Gutman]

I set the inch-pounds torque wrench to 3 nm and turned the wrench with one finger. As the drag built up the click of the torque wrench was the only way I would know when to stop. I imagine a someone, perhaps a prefessional might be able to estimate but there is no way I could even get close by hand. I first rented one at Murrays Auto parts. After a few times I bought one. They are good for trans pan bolts and lots of others. Mercedes is good about providing torque specs for almost everything.

New crush washers every time are highly recommended. I've been through a lot of them.

JD I am sure the 280 is a sweet ride, lighter and more nimble but I never drove one. Do you have a manual transmission? There is no room in the (V8) engine bay and the motor practically sits on the steering box. More everything to r&r...

[jdhill]

5-spd Getrag. One of few apparently.

[Steve Gutman]

JD- That must be a blast! I have a BMW 525 Wagon that can barely get out of it's own way. If I had a 5 speed I could mamage my rpm. THe 4-speed auto is lame. Oh well, basic transportation.