W126 muffler question - PeachParts Mercedes-Benz Forum

BENZ-LGB · #1 06-14-2002, 12:33 AM

Does anyone know how many rubber "O-rings" are used to support the muffler assembly in a 1991 420SEL.

I recently replaced the two "O-rings" supporting the muffler. One rubber ring was at the back of the muffler, close to the rear bumper. The other ring was at the side of the muffler, by the left rear fender.

The muffler still looks a little droopy...so I was wondering whether there are more of those rubber "O rings" from the muffler forward towards the engine?

I don't want to crawl under the car, searching for "O-rings" if the only ones are at the muffler (which I already replaced).

Thank you for any info.

MikeTangas · #2 06-14-2002, 01:00 AM

If the 420 has a similar system to the 560 then there are two squared rings that support the outer sides of the center mufflers. Those squared rings are a real PITA to install. You might find it easier to place a jack under the rear muffler, slip the O rings off the rear and lower the jack. Once the exhaust is lowered, get the squared rings on the body side of the hooks, then lift the exhaust. It may take another jack to carefully lift the system near the center mufflers to get the squared rings over the muffler hooks. Once the squared rings are in place, reinstal the rear muffler O rings.

BENZ-LGB · #3 06-14-2002, 06:18 AM

Thanks for the info. After reading about the PITA procedure, I think I'll let my mechanic replace the rings in the center muffler next time that I bring it in for an oil change and lube. Replacing the two O-rings at the muffler was enough to satisfy my DIY instincts for the time being

Father's Day is coming and I'd rather spend it with my kids than messing around underneath my car

#4 06-14-2002, 10:15 AM

another trick I use is to put the rubber rings in hot water with dishwashing detergent for a while to soften them and make them slippery - install is then a little easier. Rubber "donuts" on Vw's are the same PITA.

MikeTangas · #5 06-14-2002, 01:14 PM

The PITA part of the squared rings is that the hanger hook is slightly bigger than the opening of the ring, coupled with the structure of the squared ring, which makes it difficult to stretch. Hot water is a good trick for hard to stretch items. I ended up needing to use two stout (yet small) flat tip drivers to pry the ring into place, basically a wrestling match between me and the rings.

While you are in the process of tightening up the exhaust system, I would also suggest replacing the exhaust bushings. Those are the two rubber mounts (and bolts) on the bracket that runs from the exhaust pipe(s) to the tranny. Cost is something like $14.00 at the stealer. Bushing kit includes: new rubbers, new bolts and a new double U-bolt to attach the bracket to the pipe(s).

The rear muffler O rings are a piece of cake.