View Full Version : Belt squeak for 1st 10 miles every day

06-04-2013, 12:02 AM
2007 2500, 135k miles.
After it warms up the squeak stops. I can also make it stop for a few minutes by pouring a little water on it. I pointed out a pulley that didn't seem to be running true to a local mechanic. He advised it was the harmonic balancer and it needs to be replaced. I've been reading here about idler pulley replacement also.

I have to travel 70 miles to a dealer for repairs so I want to be sure I get everything done that could be the cause of this squeak.

How big of a job is this for a Mercedes dealer? Can it be done in one day? ( this is my one and only work truck) Any idea about cost?

06-04-2013, 12:55 AM
You might be able to find a local shop capable of these repairs but make sure you know if they are using MB parts or aftermarket prices. I found a shop locally that works on a lot of German autos and has some basic experience with Sprinters. Changing pulleys and alternators isn't that hard of a job if you got the time. Have you isolated with water which pulley is making the noise? My 2002 was squeaking and had the idler and tensioner replaced with aftermarket parts. Squeaking stopped for awhile and then started back but not as bad. Long story short the alternator pulley sheared off. Was it aftermarket tensioner or was alternator the problem all along? Garage replaced idlers, tensioner and alternator with MB parts and gave me credit for the aftermarket parts and some labor. The garage after parts came in had me on the road in a couple of hours. Took 2 days for alternator to come in. Use the search for threads on aftermarket tensioners I wish I did. The seller of the aftermarket tensioner blames the problem on cheap alternators. Hope this helps some

06-04-2013, 02:25 PM
Changing a front crank pulley takes about 1.5 hours--Did it last week so its fresh in my mind!
You need a holding tool plus a big torque wrench plus a "mamoo" of a knuckle bar to tighten to yield by angle tightening.

Why did I have to change it---Well in short the customer insisted in using AFTERMARKET JUNK!

The balance ring had sheered off and ripped into the alum pan---Made in China was still evident in pride of place on the ripped up ring!
Maxim #1
Use only genuine parts on Benz's--Its folly to do otherwise!

1) Squeal is due to misalignment of pulleys.
2) Belt groove wear even though it looks like new--they don't crack anymore you MUST use a gauge tool to measure groove depth.
3) Belt tensioner worn change out at 100K miles

Throwing water on the problem is like having ice on the road, the tires don't grip, so the road noise disappears . The squeal is eliminated temporarily because the belt stop skidding/slipping on the pulley in question--until it dries out.
Slippage case heat, heat attacks bearings/shafting and the free wheel pulley arr' on the alternator. Heat causes bearing metal/lube distress, part breaks and falls on the road or goes through the radiator causing costly contingent damage. Cheap parts don't have the same EN quality control or shore harness so its breaks under load.
All easy stuff really.:laughing: