hachiroku

belt came apart and took out my thermostat bleed nubbin. the one that attaches to the expansion tank hose. .wonder what happened...bad quality control? pullys were replaced 20k ago but belt was reused as my mechanic said it looked pretty new. do we have aftermarket belts that perform better? Goodyear Gatorback, Gates Kevlar, Etc? Honestly never had a belt fail on me before on any car. At the shop now for repairs.

hachiroku

had the indy replace the belt, 2 pulleys, and thermostat...also ordered UPD pulleys and will be replacing those once they arrive. today was an expensive day...

hachiroku

Thanks to shardul for the UPD Upgraded Pulleys. After inspection, one of the pulleys encountered a wobble of 2-3mm causing the belt to slide off the end of the pulley a hair...when this occurred the belt shredded one rib and the rib began its destructive path to snap off the plastic air bleed tube off the thermostat housing. This all was due to the fact I floored it on the freeway to pass a car in the left most lane on the highway putzing around at 70mph. Transmission dropped 3 gears and once I took the next exit all was forsaken. The pulley only was 2 years old with maybe 8,000-14,000 miles on them before they failed. I had them all replaced when I serviced my headstuds, valve covers, oil line o-rings, oil pans, etc. I guess the many instances of hooning and allowing the transmission to drop multiple gears slowly chipped away at the strength of these throwaways.

Here are some pics of the new UPD pulley's installed. Prior to this I had my local indy install brand new pulleys and belt. Factory plastic pulleys only have 15 miles on them if anybody is looking for a factory backup, tensioner pulley has 8-14k. PM me if you are interested. Will let them go for not much.

nikehead1980

Yep same thing happened to me Barry! No indication of it starting to fail which is scary, I made a post on this too. My pulleys were all broken too so I'm thinking maybe one of them broke and that caused the failure.

I see Weistec does make a billet version which I'm interested in:

Billet Idler Pulleys, M156 SKU:01-000-00093-3

$549.99

Weistec Engineering complete set of CNC machined billet aluminum idlers. The factory Mercedes parts are plastic and have been a known problem for many naturally aspirated vehicles. This is a great solution for long term use in stock to highly modified vehicles.

Key Features:

• CNC machined 6061 aluminum
  
• Hard anodized to military spec
  
• Direct replacement/bolt in for M156/M159
  
• Utilizes factory belt
  
• 100% serviceable
  
• Great for use in harsh environments
  
• High quality bearings