SLK320 Belt Tension Woes

[Air&Road]

My 2001, 115,000 mile 3.2 spit out the drive belt. I bought a new idler pulley and an updated belt tensioner. I got it all on, started it up and it squealed before throwing the belt. The factory belt is supposed to be 2390 MM. it was loose, so I ordered a 2385 MM and a 2380 MM belt. It’s as if they are the same size because the shorter ones don’t seem to be any tighter.

I have thoroughly checked all components and idlers. Everything seems tight and smooth.

Is it possible, that the new, updated tensioner is bad?

[vince]

Dumb question, but did you remove the pin that holds the tensioner in the installation position?

[engatwork]

Another dumb question Larry and I'm sure you have checked but did you try turning the inner part of the compressor? Does everything look like it is properly aligned?

[Air&Road]

Thanks Jim. I checked the compressor first thing after it spit the belt. Checked everything to make sure it’s tight and smooth. Replaced the idler and tensioner.

Vince, you hit it and i thank you. I didn't know or think about the pin. I don't wrench much any more, at least on cars. The last tensioner i replaced was more than twenty years ago on my 300E. I got to the hangar this morning and snaked the belt in place, levered it over, pulled out the pin and all is well. I have even driven it over a hundred miles today with no problem.

The technical side of this forum continues to be incredibly awesome. Thanks guys!

By the way, when you get my dunce cap ready, let me know and i will supply an address.

[engatwork]

I don't wrench much any more, at least on cars.

Are you mostly wrenching on the airplane these days?

I just took for granted you had removed the pin.

[Air&Road]

The airplanes and John Deere Gator clutches. Most of my time is spent enjoying retirement. Great hunting trips, going to the Galveston Beach with the kids and Grandkids, fishing and flying. Life is good.

[vince]

Glad that resolved the issue. I saved one of those pins in case I ever need to remove the belt to replace a pulley, water pump, etc.