Motor mounts replacing on a 76 280C - PeachParts Mercedes-Benz Forum

Tomas7 · #1 05-12-2018, 02:30 PM

Do I need to remove the front exhaust manifold in order to get to the arm that grabs the mount from the top?
Is there any trick or shortcut to doing this?
I can support the motor with a 2X6 from the bottom on the oil pan right?

Sugar Bear · #2 05-12-2018, 03:54 PM

Haven't done the mount on that exact car but several similar ones. The arm is left in place, the bolts removed, the engine is raised then the mount is slid out horizontally with some finagling. The new mount is taller than the old so additional lift/room will be needed to get the new one positioned.

Lifting the engine with a 2 x 6 on the oil pan, I've done it but watch for any deformation in the pan. Putting a folded up towel or a piece of carpet on the board may help. Do not put your hands in any potential pinch points in case the engine shifts. I like to put a block between the upper oil pan and the center frame rail as a just in case. Watch the fan to shroud clearance, wiring and hoses in general for anything getting stretched too far or interfering with raising the engine...lift a little then look, lift a little then look until you get enough clearance.

Good luck!!!

Mike D · #3 05-12-2018, 04:12 PM

No need to drop the exhaust. Some /eights have an engine shock which must be loosened. Fan shroud removal might need to be removed/loosened for clearance.

First and foremost, THOROUGHLY CLEAN the Allen sockets holding the mounts to the cross member BEFORE you attempt to loosen them. I'm talking, get in there with a Q-tip, solvent, compressed air and probe kind of clean. Use a high quality Allen wrench set and ensure the wrench is fully seated in the bolt head.

Lift the engine only high enough to remove/replace the mount despite the temptation to, "get plenty of room to get in there".

Do one side at a time. Snug, not tighten the first side you do before attempting to replace the second. You'll need to do a bit of prying to get the second bolt aligned and started. This is normal. Don't force the bolt. Just keep working at it.

With the mounts still loose but snug, start the engine, cycle from "reverse" to "drive" (if it is an automatic transmission) a few times to "seat" the engine.

Use a "Never-seeze" type of product on all threads and re-install all heat shields no matter how superfluous you might think they are.

I'm not a big fan of the floor jack/ wood block method but I have had to resort to the method many times. I much prefer using an engine cradle or Cherry-picker as this lifts the engine straight up and lessens the need to "finagle" the bolts for final alignment.

Tomas7 · #4 05-12-2018, 04:47 PM

Thanks Sugar Bear and Mike D. BTW Mike D, I am also replacing the engine shocks. There are two, one right on the driver's side engine mount cover and the other one, in the front by the alternator behind the balancer (which I have no idea how to get to).
The saga continues.

Sugar Bear · #5 05-12-2018, 05:41 PM

Good advice about the allen head bolts..follow it well. Consider removing the engine shocks, do the mounts and then install the shocks.

Benz Dr. · #6 05-12-2018, 10:23 PM

Remove the top of the shock and undo the two sub frame mounts and then lower that side on the sub frame. Motor mounts will be right in front of you. Expect to replace the motors mounts anyway.

meltedpanda · #7 05-13-2018, 05:23 PM

and lift straight up , if the engine moves back they are a bit.. to get back right . It helps if you have a mate to help you

Tomas7 · #8 05-17-2018, 02:34 PM

Thanks for all the good tips gentlemen.