Reinforcing W126 trans mount
 

I will have to replace the transmission mount on my W126 300SE soon. The OEM Mercedes one is almost $300,- and I'm getting a little tired on spending that kind of money on rubber mounts. So far I've been mostly a good boy and have installed Lemforder and Mercedes.

I did some research and did find several videos of people reinforcing motor mounts with polyurethane, would this be a good idea to do this with a $16 Meyle transmission mount? Any thoughts?

There's not much to a transmission mount. Two pieces of steel suspended by a bit of rubber. If you are planning to fill the gap with a urethane product then it won't matter if it is a $16 or a $300 mount.

Don't use a urethane with a hardness factor over 35.

I suggest using a two part urethane mix because it cures so much faster. Less than 48 hours as opposed to two or three WEEKS (yes, I said WEEKS) required by the tube sealants.

Initially you might notice an mild increase in vibration at idle but after a few miles it subsides.

Attachment 148835

Engine and transmission mounts filled
The mesh is just some fiberglass mesh I had. I trimmed it away after the urethane skinned. Probably a waste of time but, it was there and I was there..

I guess the question I have is why you feel the need to reinforce the trans mount? It isn't exposed to the heat, vibration, or fuel spills that the engine mounts are. If your transmission isn't dumping oil all over the place, a good quality mount should last a decade or two easily.

Gotta compensate for that awesome 143 horsepower produced by the mighty OM603 I guess.:rolleyes:

Only because of the "inferior" quality of the non Mercedes mount, to make it last longer.

That's the info I needed and did you do this with your mount for longevity?

Yup and also to make up for the cheap Meyle mounts which collapsed after only about a year's use.

I've used the good Benz mounts and they lasted 5+ years but as you mentioned, the initial cost is a bit of a choker.

M103 + W126 cars eat up motor mounts, regardless of brand. Plus the damned exhaust downpipes are routed a bit too close to either that caster rod bracket support or idler bushing. I fixed the support brace by putting a dimple in it, now the pipe sits on the idler bushing. :rolleyes:

I am to the point where I am going to make some metal shims to gain the needed 1/2" of rough clearance needed to stop this NVH. My mounts are not fully collapsed, just sagged a bit. Not interested in spending $200 for OEMs currently.

Permanent solution is to reroute that downpipe, I am nearly to that point. :mad:

Aftermarket trans mounts work fine on these W126 at least.