Need to do something about squeaky idler on 603 - Page 3 - PeachParts Mercedes-Benz Forum

cmac2012 · #31 08-09-2020, 01:11 AM

I'm having a renewal of the old issue but not quite as bad.

Sorry I deleted the pics in the OP. I can't get back in to edit the photos back in, so I'll do it here:

I'm getting parts from a '91 350SD, the idler wheel looks parallel. I'm going to get the parts tomorrow. I could use a one year wait to buy new parts again. This car had 248K.

Diseasel300 · #32 08-09-2020, 01:30 AM

Make sure you get the big washer that goes behind the pivot bearing. If the bearings on the one from the 350SD are smooth, use it. If they're gritty or stiff, don't waste your time. It's such a PITA to change, it isn't worth using already worn out parts. The torque spec on the tensioner pivot bolt is very high, I don't remember it off the top of my head, but it's very tight.

I looked back through this thread and I didn't notice if you replaced the shock absorber or not. If not, replace it with a new one. It keeps the tensioner from rapidly vibrating which will quickly toast the bearing and can cause things to loosen up or break.

cmac2012 · #33 11-30-2020, 12:36 PM

Quote:

Originally Posted by Diseasel300

If the tensioner pivot failed in only a year it could only be a handful of problems: cheap pivot (buy an Ina), failed tensioner shock (will toast the pivot bearing quick), failed pulley bearing (again, buy Ina), failure to transfer the spacer washer from the old pivot to the new one.

You can remove the tensioner assembly without removing the radiator or the fan. Take the pulley off, then stick an allen bit (I think it's 12mm?) into the pivot bolt and use a wrench to turn it out. It'll be tight, but it'll just clear the fan. Make sure that spacer washer is behind the pivot bearing, if it's missing or not seated it will cause failure of the bearing in the pivot.

I'm still having trouble with the pivot and the idler being askew. Haven't driven it for a few months. I've got to finally do this right. Miraculously I found this part on eBay (the space washer). Not sure what I used last time. I found this by searching the part number for the washer that I included in one of my posts above:

https://www.ebay.com/itm/Mercedes-Drive-Belt-Tensioner-Pulley-Spacer-Washer-Shim-A6019901740-/174283678662

cmac2012 · #34 12-14-2020, 03:45 AM

Quote:

Originally Posted by Diseasel300

If the tensioner pivot failed in only a year it could only be a handful of problems: cheap pivot (buy an Ina), failed tensioner shock (will toast the pivot bearing quick), failed pulley bearing (again, buy Ina), failure to transfer the spacer washer from the old pivot to the new one.

You can remove the tensioner assembly without removing the radiator or the fan. Take the pulley off, then stick an allen bit (I think it's 12mm?) into the pivot bolt and use a wrench to turn it out. It'll be tight, but it'll just clear the fan. Make sure that spacer washer is behind the pivot bearing, if it's missing or not seated it will cause failure of the bearing in the pivot.

I've been trying to take your advice on the Ina brand but it's tough going. I found the idler wheel and that's about it.