Pagoda SL Group

W113 Pagoda SL Group => General Discussion => Topic started by: rwaw on April 01, 2004, 02:16:26

Title: knocking noise
Post by: rwaw on April 01, 2004, 02:16:26

Think I have discovered where an irritating knock on right hand side at rear seems to come from.
The rear silencer on the exhaust when vibrating knocks against the bottom of the right rear wing where it curves at the bottom edge.
Mount/rubbers are ok;what do the experts suggest I do next, can I just "bend" teh bottom edge of the wing outward somewhat ??
Thanks as usual.


280SL 1969 Euro RHD

Title: Re: knocking noise
Post by: ja17 on April 01, 2004, 05:53:25

Hello RWAW,
Bending the exhaust would be better. Another trick would be to replace the rubber rings with two new on one side. The new rings often are stronger than the stretched and tired old ones. This may be enough to move the system over a bit.

Joe Alexander
Blacklick, Ohio

Title: Re: knocking noise
Post by: ted280sl on April 01, 2004, 05:58:12

The knocking noise you describe is usually from a worn or broken rubber bushing. There are six rubber dougnuts on the exhaust system. They are not expensive and are not difficult to replace. Another suspect could be a rubber bumper which mounts above the rear exhaust pipes and stops the exhaust pipes from knocking against the rear of the car.
Best of luck,
Ted 1969 280SL LHD w/ Euro headlights

Title: Re: knocking noise
Post by: Richard Madison on April 01, 2004, 06:40:20

The source of rear end bumps and knocks is not easy to pin down...might be the exhaust, the spare loose in the trunk, or the rear axle mount.

A support stalk comes up from the rear axle ending in the rear rubber mount. The mount is accessible under a plastic cover in the front center of the trunk. A dried up mount transmits knocking sounds from  road bumps.

A new mount is avail from MB and re-sellers for about $60...replacement is a do-it-yourself 15 minute job involving just a few bolts.

A new mount did wonders to relieve most of the myserious knocks from the rear of my car...

Richard M

'71 280 SL, Tobacco Brown, Cognac interior, Tan top, Jump Seat, 80K orig miles, NYC.

Title: Re: knocking noise
Post by: rwaw on April 02, 2004, 03:41:57

Thanks for the speedy and helpful replies as usual!

280SL 1969 Euro RHD

Title: Re: knocking noise
Post by: Dick M on April 30, 2004, 00:28:57

I have "clunck" sound on drivers rear wheel when making semi-agressive turns (slalom turns).  We think the issue is that axle is actually sliding back and forth with each turn.  Attached pic explain how this occured



Download Attachment: (http://images/icon_paperclip.gif) axle 1copy.jpg (http://www.sl113.org/forums/uploaded/Dick%20M/200443022554_axle%201copy.jpg)
79.9 KB

Has anyone else experienced this problem?

Dick
280SL

Dick M
1970 280SL