W109 300SEL 3.5 engine mount alignment - PeachParts Mercedes-Benz Forum

alabbasi · #1 12-28-2022, 04:45 PM

Is there a knack to putting these engine mounts on? I have them bolted in with the small bolts on the drivers side but the engine seems to now be out of alignment where the large 19mm bolt hole on the engine bracket does not line up.

It should be a simple job but it's turning into a pain

Tony H · #2 12-29-2022, 12:49 AM

They are side specific-I think the longer one goes on the DS-the engine is slightly offset to the PS (to provide clearance for the steering gear box maybe)?

alabbasi · #3 12-29-2022, 02:04 AM

Tony, the mounts or the arms?

Thx

cth350 · #4 12-29-2022, 12:05 PM

I think I last did this to a 300sel 3.5 in 1989, so take my dusty memory with a grain of salt. I kinda recall keeping the motor elevated while I got both large bolts small bolts in. Then letting them take the load.

Eyeball the old mounts, any evidence of sidedness? (even though they are probably collapsed). What about front vs back orientation (as in spin it 180 degrees)?

-CTH

alabbasi · #5 12-30-2022, 12:55 AM

Charlie,

Thanks for the feedback. I've spun them around both ways and it won't align. I'm going to disconnect the other side so that I can the engine around. I suspect that because the other side is collapsed, it might be screwing with alignment.

Thanks

Tony H · #6 12-30-2022, 03:31 AM

thought you were talking about the arms-sorry. The left and right are different.

Idle · #7 01-01-2023, 09:59 PM

I ran into this when replacing the engine in a 124 300d. I finally loosened the bolts holding the transmission mount thus allowing the engine to swing around a bit in order to get the mount bolts to line up.

I didn't remove the bolts. But everything got a little easier to live up once you could move the entire engine/transmission assembly a bit.

I also used a centering tool to line up the hole in the engine arm to the mounting point. This would push the engine into place, or get it closer to where it should be, without chancing gauling up the threads on the mounting bolts.

Once I had both bolts started I went back to the transmission bolts and made sure they were lined up like they were before I messed with them. There is an amazing amount of slack in that hole in the engine arm and you don't want to mount the engine in there crooked.