W124 Aux-Belt loosening
 

Hi, I have a '93 W124, M104 motor with the earlier style over-complicated tensioner set-up (same as M103). I want to slacken the belt to check a suspect noisy pulley but the tensioner adjustment rod/lever is stripped- I have loosened the tensioner centre 10mm hex bolt before anyone asks! - is there any other way I can loosen the belt to give me enough slack? I've thought about maybe taking off one of the idler pulleys but I suspect it would be very hard to get back on as I'd be fighting against the belt... Would disconnecting the tensioner shock top bolt give me any play?

P.S. the belt has good tension and I can twist it 90 degrees at the longest span with 'reasonable effort'...

Hi chazola,

I've attached a link to a tech article that I hope will be useful to you in troubleshooting / fixing your tensioner set-up. If you have any further questions, feel free to post a Comment just below the article and someone will get back to you with more detailed info. Hope this helps and best of luck! :)

Pelican Technical Article - Mercedes-Benz W124 - Drive Belt Tensioner Replacement


-Dmitry

On a multi rib belt the tension should not be checked the same way as a single V belt - so 90 degrees on the longest length is probably too slack. The built in tension gauge will of course not be working...

As your adjusting rod is damaged I'd look at removing either the power steering pulley or the water pump pulley so you can get rid of the tension in the system and get to the damaged part.

I guess you'll be off down the scrappy this weekend then?

Chaz did you turn it the wrong way .Or was the adjuster fitted the wrong way to start with .This will shear off or snap if it was ..