After a cursory search, I couldn't find the answer to:

Has anyone successfully replaced the tensioner pulley bearing? My belt was showing some edge wear and after checking everything I noticed two things:

1. There appears to be a slight groove on the inboard side of the pulley itself...
2. The bearing sounds a little chunky, not very smooth.

I hate to buy the whole damn tensioner when it seems to be a bearing issue.

Any thoughts, comments, criticism, flames, etc etc etc

I'm assuming that the Torx bolt is the actual retainer and the nut is for locking it in place?

Thanks,
Robert

 

the torx is used for removing the belt, the nut for holding the pulley on the tensioner. for the cost of the bearing you can prolly replace the entire pulley

 

+1

Buy a 90mm pulley from a parts store and call it a day.

http://shop.advanceautoparts.com/web...ens_10267310-p

 

I don't know the cost of the pulleys, but here is the bearing costs. (CLICK)

 

We had some one at Dragon a few yrs back that had to change one out, I think it was about 40 bucks and it took about 10 min to do

 

Not on mine. Mine has a hex boss to put a socket on to release the tension. The torx will remove the pulley.



The bearing itself can be replaced if you can find out the correct one. But then the old one would need to be pressed out and the new one pressed in the pulley. Or a big hammer can be used if you feel lucky.

 

^ thats an aftermarket tensioner not an oem setup

 

It is an OEM, but maybe the SRT is different? I didn't realize this was posted in the SRT sub-forum.

 

yes srt is different than the n/a model. i can find a version similar to yours online but its over 100$ more than the oem slk32 mercedes part

 

The NA and SRT have different tensioners. The NA uses the 17MM (?) boss and the SRT the male Torx. headed bolt to remove the tension in the belt.
The tensioner pulley and the other tensioner pulley (not the SC tensioner pulley) on the SRT are the same ones, this from the MikeR post from a while back. So if you are buying one buy two just in case.

 

I found the NSK 6203EU bearing for about $5 online. Better than the $250+ for the whole tensioner.

BTW, I have the two similar pulleys left over from the NW PSK. The bearing numbers are different (different mfg.s), but otherwise they look the same. Of course, those bearings don't sound too great either.....

Any who, thanks for y'alls input. As always, this forum rocks...

 

you dont have to buy the whole tensioner just buy a new pulley

 

If you think different numbers come from different manufacturers you may find yourself sorely upset.
A 6203 bearing is 7mm smaller in the OD and 2mm thinner than a 6303 bearing (47mm OD x 14mm thick). The ID is the same at 17mm.

The idlers use a 6303DU bearing by all account and as mentioned in my post which is linked above. (CLICK)

The PSK uses a 6203 bearing which is probably the SC idler bearing size as well.

Bearing sizes.(CLICK)

 

Ok, my tensioner is the source of the rattle in my car that has been there a year now. (Went to Glover's Garage today and he proved it to me with his stethoscope). The rattle is the cylinder, it goes quiet when he presses on it - he assures me that is it a conducted noise from a bad bearing in the pulley.

I thought that I could order the part and it would come with the cylinder as well - but no. My car is a limited, now, autohaus.com has a part for the 2003 SLK320 and the Crossfire. They are different numbers and the Crossfire part is $20 more.

What the hell is the difference between the tensioner on the limited and the one on the SLK320?
Should I try to find the cylinder as well?

The parts they are selling look just like what James posted above. He suggested, and I agree, to replace the idler pulley as well (the small one up on top of the engine, highest pulley there.) The Crossfire Idler is almost TWICE the price of the SLK320's.

 

Why not just replace the bearings or the pulley? It's cheaper and you will have done your part to save the planet today.
Why throw away parts that are fine?

 

The guy doing the work recommends replacing the whole assembly - says that labor will be cheaper (and at $85 an hour, that is a good point.)