Check those motor mounts! OM603 W126 - PeachParts Mercedes-Benz Forum

redassag00 · #1 12-26-2008, 05:03 PM

I see a lot of W126 OM617 replacements but very few OM603 W126 setups.

Heres my experience.

I bought my 300SDL in Aug of 06, with 260,000 miles, the engine mounts, upon initial inspection had the Blue and White MB sticker on them, and still looked good.

Fast forward today, 286K, I notice a little more vibration at idle during stop and go traffic. I figure its time to throw some mounts in it. I went ahead and spent the extra few bucks and got lemfoerder over the other choices.

Driver side wasn't too hard, and wasnt in such bad shape....

New one on the right....

The passenger side one was another story....

New one on the left this time....

Here is a pic of the new one, driver side, and passenger side, left to right.

Check your mounts!

This was a one hour procedure, I used a floor jack with a block of wood to support the oil pan (don't use the side oil pan on the OM603), eye protection and 6mm and 8mm allen wrenches and 3/8" Allen Drivers. You'll also need vise grips and a 10 mm socket, and a long punch.

On the W126 with the OM603, I let the fan shroud loose to have some wiggle room. The Throttle linkage stayed in place this time.

I used the block of wood to support the engine a little bit, and then removed the 2 upper bolts for the shock and the lower bolt for the shock. You'll need the vise grips to gently grip the shaft to prevent it from spinning. Repeat for the passenger side.

I used some simple green to clean the grime off the shocks. Inspect the rubber and metal hardware. My rubber isolators still looked good, so I sprayed them in silicone to condition them a little.

Next I used a flashlight to look inside the cradle to inspect the 8mm bolt that faces upward. Inspect for debris/mud. I used a coat hanger to clean the hole out before going in with a 8mm allen driver. Loosen one side and then the other to make sure you can get both sides. Once you've done that, then start on one side.

I did the driver side first.

Remove the 8mm allen bolt completely, then from the top, you can reach with an allen wrench and loosen the two 6mm bolts. These weren't too terribly tight, and I backed them out. You can now go under and use the jack to raise up the engine, to get some clearance. I removed the heat shield, and then worked the mount out. I sprayed the mount with some degreaser and used a wire brush to clean it up.

The new mount can go in, and you can wiggle the freshly cleaned head shield on top of the mount. Clean and reinstall the 6mm bolts, and then from under the car, I put the punch into the hole where the 8mm allen goes in and lower the mount and have it aligned. Now you can install the 8mm bolt. I installed it a few turns, keeping it loose so I have play for the passenger side.

The passenger side is a little tougher, as there is not access from the top for the 6 MM bolts. I did everything completely from the underside.

You may have to reposition the jack on the pan to get the clearance, but it can be done.

Once you have the passenger mount installed, use the punch and lower the engine, carefully installing the 8mm again. Tighten up but not all the way. Same for the driver side. Start the car and let the engine idle for a few minutes to settle the mounts.

Once its settled, you can tighten the 8mm bolts down and enjoy your new mounts!

pawoSD · #2 12-26-2008, 05:43 PM

I thought the 603 had different/fancier mounts than the 617....

Jeremy5848 · #3 12-26-2008, 05:46 PM

Quote:

Originally Posted by pawoSD

I thought the 603 had different/fancier mounts than the 617....

Yes, the 60x engines have "hydraulic" mounts that have oil (or some liquid) in them. More money, of course. AFAIK, the 61x engines got solid rubber mounts.

Jeremy

pawoSD · #4 12-26-2008, 05:51 PM

It says in the post that they're from an SDL.....?

mytmousemalibu · #5 12-26-2008, 05:57 PM

At work, my experiance with parts... Lemfoerder replacments are great, nice quality stuff, much better fit, VS. Meyle, Febi, Boge/Sachs, etc.

redassag00 · #6 12-26-2008, 06:24 PM

Yes, the W124 OM603 mounts are hydraulic.

see my thread from dec 06 about w124 OM603 mounts.

Anyone done W124 OM603 Motor Mounts?

Those are the round liquid filled units.

Charles_B · #7 12-26-2008, 06:32 PM

Looks like you could have rummaged through my garbage and took my old mounts, since my old set matched up with your old set. Engine definitely smoother idling and can take sharp corners without fan blade hitting chassis, since I replaced them. Did my transmission mount and shifting bushings while I was under there. Car gets smoother everytime I replace something.

pawoSD · #8 12-26-2008, 09:40 PM

Quote:

Originally Posted by redassag00

Yes, the W124 OM603 mounts are hydraulic.

see my thread from dec 06 about w124 OM603 mounts.

Anyone done W124 OM603 Motor Mounts?

Those are the round liquid filled units.

Yeah our W124 with the M103 gasser sits on those same mounts.....they really work! You can't feel anything!

redassag00 · #9 12-26-2008, 09:52 PM

I think the W124 OM603, and I-6 gasser W124 and W126 use those.

I remember when I had the 87 300D, I changed the driver side one first, then the passenger side one a week later, and that one made a HUGE difference (had ruptured and the fluid seeped out). Swapped a fresh one in and it was as smooth as a gasser

Pawo, I still havent done those flex discs and center bearing yet. I drove it tonight and the vibration is 'cleaner', as in I only feel the vibration now, over 80 mph. I need to check the wheel balance again too. I know I have one wheel that isn't true and its balanced as best as it can be on the right rear.

rivermasternc · #10 01-06-2009, 04:47 PM

Quote:

Originally Posted by redassag00

Pawo, I still havent done those flex discs and center bearing yet. I drove it tonight and the vibration is 'cleaner', as in I only feel the vibration now, over 80 mph. I need to check the wheel balance again too. I know I have one wheel that isn't true and its balanced as best as it can be on the right rear.

Thanks for the write-up. My new mounts and shocks should be delivered today. Have you checked/replaced the transmission mount?

-Scott

redassag00 · #11 01-19-2009, 05:34 PM

Yup, did that one too. The top bolt is tricky to get at but its attainable. Don't forget to have a new zip tie handy to reattach the kickdown wire that runs across the crossmember when you drop it.

Hit Man X · #12 01-19-2009, 06:02 PM

W126 300se/l use the standard "style" mount found on the V8s and the SD/L, but they're specific to the M103/W126. Left and Right are different PNs. Look up the pics, pretty weird.