Baltistyle

I figured I would ask the pros here. I currently have an 83 mm UPD clutched pulley purchased in later 2017. Probably ten k miles on it. Raceiq tune only.

Recently the engagement has gone from the squeak/chirp to more of a grind. Before doing any possible damage, I pulled the pulley off To see what was going on.

Original gap gap seemed too big when using a feeler gauge. This pulley upon original installation did not require any shims to meet spec.

Here are are some pics.

Do we think that the noise is because of the rust? What would cause the rust around the rivets of the pulley or the accumulation of rust on the clutch friction plate recesses (clutch material?). Is this because I don’t really drive the car a lot and it got wet and I have not been able to wear the rust away?

Does the magnet and friction disk look OK? It does feel slightly concave from the outer lip?

lastly, Is the magnet with friction disk material something I can find to purchase if needed?

i have replaced and retightened the pulley That seems to have tightened the clearance but before driving I just wanted to reach out here and see if anybody has any ideas or if at 140,000 miles it’s just normal.

Thanks all!

GinDistiller

The stuff you're seeing on the plastic cover is belt material, nothing (necessarily) to do with the pulley clutch as far as I'm aware. It's called a 'clutch' but doesn't really have any friction material like the clutch on a manual transmission does, it' just two metallic surfaces.

If you don't have a belt wrap kit I'd start there, and definitely check all of your other pulleys for drag and noise. The grinding noise might just be a pulley when extra load is put on the belt by engagement. I had a mess of that black stuff, new belt and BWK and it hasn't returned.

Also, I have the same pulley, no shims, and the gap is larger than specified. I've been told this is normal and with no shims there isn't much else I can do to close it...

tw2

My gap is slightly over the maximum with an aftermarket pulley (83mm UPD) and no shims. I also have black grud on the under side of the engine cover. If you are worried about the surface rust you can probably give it a light sand.

Munchy

iTrader: (1)

Under the cover is probably just from dirt coming off the belt. I dont think that's rust though. I belive it's clutch material. Notice the contact surface isn't a flat smooth piece of metal but seems to be something else in it. Anyways I usually clean off the contact surfaces with rubbing alcohol and after I do that my supercharger engages nice and hard for the next few days.

Baltistyle

Thanks for all the suggestions, please keep them coming.

The belt wear is a new phenomenon. I don't notice any appreciable slip when everything is new and tight. And I'm honesty not sure how long a belt lasts considering I just proactively change things. I think the bwk may be next on the list though. For now I have ordered a new belt, a tensioner and a dual idler pulley. The tensioner pulley does have "some" play in it and perhaps those bearings are giving me the crunch.

The reason I ask about the clutch friction disk on the supercharger side (not the pulley side) is because the surface seams worn enough to have become slightly concave. Is this a replaceable part?

Thanks

tw2

Yes but you have to buy the entire assembly from Mercedes and it is quite expensive.

StarvingArtist

It looks normal to me, but then I've never seen a new one either.

sjc246

The friction surface looks fine. You can clean it up with semi fine sandpaper then a bit of acetone on a clean rag to take off any remaining dust or oil. You can do the same with the pulley. It is available as a replacement part (just the friction surface, the magnet is separate). I do NOT recommend replacing it. It is an interference fit part. Removing the old one is a tough job with the supercharger already removed and will result in destroying the old part; in theory you can do it in the car but you need a special puller and probably a lot of luck. I've seen them still working fine in pretty bad shape (very uneven wear or even deep gouges from the rivets in the pulley protruding past the clutch surface).

Exotic-metal55

Both look ok, just clean them up and set gap back to spec or as close as possible. cover grim is normal from belt wear or belt slip. a Belt wrap kit will reduce that mess a lot.

VictoryRoadPerformance

The clutch delete pulley has been a solution for many people with magnet issues. This will completely eliminate the magnet and the supercharger will function like a fixed pulley.

https://vrpspeed.com/product-categor...55k-amg-m113k/

Baltistyle

I replaced the supercharger tensioner, belt and dual idler pulley.

I need to drive it some more but the dual idler pulley was destroyed and was probably the cause of some of the issue.

Thanks for all of the suggestions. I will report back.

cnterline

Your fine pic of new stuff ,