Idler pulleys blew
 

Hey guys... 109000kms and the idler water pump pulleys seized and blew the belt!! No other damage thank God... thinking I'm gonna go with weistec pulley kit for the M156!!! Does anyone know what the 5 pulleys are for? Gonna replace the belt tensioner at this point too... any input guys would be great...

Thanks just contacted them!! Does the kit come with new bolts as well???

Thank you Shardul.... looking forward to your shipment!!

My pulleys did not come with new bolts. I reused the existing fasteners.

I'm lazy today. Where's the Pulley Install DIY??

Just a update. Got my UPD pulleys installed! With a machinist background in aerospace, I must say the machining on the pulleys is good... bearings arnt IMO the best and probably wont make the same milage as the OEM ones at 60k miles or 100k kms.... JMO!!! I was told to reuse all the OEM hardware except for the steel caps/covers, however my 09 has the lower #7 idler pulley, OEM was grooved so I replaced with grooved, UPD kit typically come with a smooth pulley but I feel it will cause premature belt wear as the grooves of the belt would be running on the smooth pulley between the crank and A/C compressor, and this pulley can not use the OEM bolt as it has no shoulder for the bearing ID (inside diameter) so as posted in other threads Merc part # 0009902906 is required for the updated bolt.... cost for the bolt $12 CAD.... all in all nice look just sucks there almost impossible to see once all the plastics are back on... longevity of the bearings TBD....

Sorry I am not following entirely. I just ordered the UPD pulleys as well. Do I need ANYTHING additional that I have to source on my own?

You mentioned this "Merc part # 0009902906 " is needed for the installation? Is this mandatory? What is for?

UPD say you dont need anything else.. however if you have the lower #7 pulley as I mentioned you will need the bolt from merc...

I have a 2011 c63 do I need the bolt? Which years have the lower #7 pulley? How do I find out?

This post shows all the pulleys

M156 Billet Ider Pulley Kits in Stock - Page 2 - MBWorld.org Forums https://mbworld.org/forums/c63-amg-w204/587288-m156-billet-ider-pulley-kits-stock-2.html

Heres a few pics... left one is OEM plastic pulley bolt.. right one is the merc part # as mentioned with the shoulder to match ID of bearing. Also added pic of the bolts in the pulley to clarify bottom pic shows OEM (plastic pulley) bolt not in contact with ID of bearing .. Hope this helps
https://cimg2.ibsrv.net/gimg/www.mbw...0186c6d267.jpg
https://cimg7.ibsrv.net/gimg/www.mbw...12563fbcc9.jpg
https://cimg0.ibsrv.net/gimg/www.mbw...2c866e9643.jpg

Heres a pic of mine... yellow handle is pointing at #7 pulley location...
https://cimg8.ibsrv.net/gimg/www.mbw...d18c9e27d3.jpg
https://cimg2.ibsrv.net/gimg/www.mbw...39d1b18f73.jpg

I plan to replace my idler pulleys too. But not yet decided what to buy Weistec or UPD. :nix:

How can you tell the quality of the ball bearings in the idler pulleys? I know there are many levels of quality and prices for bearings (just look at the ball bearing for something like skate boards!) but I don't know of a way to tell the quality on the idler pulleys. I would think with the best bearing both the OEMs and the well machined aftermarket pulleys would last as long as the car, but with poor bearings both will fail. I took the belt off my 2012 at 28k miles and 3 pulleys already had rough bearing but hadn't failed. I replaced them all with OEMs but at the time was not aware of the aftermarket pulleys. I also have the extra pulley at the bottom and the factory runs a flat pulley on the ribbed part of the belt. But that pulley barely contacts the belt and must just be there to prevent the belt from starting to flap, so I doubt it makes much difference if you replace it with a ribbed one.