c32used

I don't know if this helps but I read this in another thread..

quote...


**I upgraded my pulley w/ 168mm RT pulley. This was initially done before ECU tune. I noticed the power increase... but also noticed harsher jerk when the S/C engaged. It was very bad especially when S/C engaged during the shift. I also heard the infamous chirp, which was not there w/ stock pulley.

About 3 months later, I went back to Euroelites for ECU upgrade as Euroelites claimed that the ECU tune would reduce the jerk, if not make it completely disappear, and Oliver was there to do ECU tuning.

After ECU tune, I personally could not say there was any power increase. But this is acceptable as I don't expect ECU tune alone would increase much power - I'd guess around 10whp/10wtq. What I noticed was the jerk was a lot milder but the chirp was still there.

I haven't done post-mod dyno (will do it after cooling upgrade later this month) to check the numbers after ECU+pulley.

I then came back to Euroelites about the chirp.... Adam brought me to FJ and explained the situation to my SA and foreman. In the end, FJ replaced my S/C clutch. After this, the jerk was even milder - still there but not that bad - but the chirp was gone. So I decided to just live with it.

They also helped me to explain to FJ when my idle pulley was bad.

In summary, like housclass thought, my experience w/ Euroelites is nothing but good. They gave me good price and treated me w/ courtesy - just like most other members here shared their experience.

I'm not sure about 65... but your 55 should be exactly the same setup w/ mine (including the pulley brand)... and I know they've done numerous upgrades like this (ECU+pulley)... they've done even more complicated upgrades (like neveo, rocketw19, nsm, etc.) so logically speaking, chances they screwed up this job should be quite low. But hey... $h!t happens. One possible reason is your car was treated badly by previous owner and this whole upgrade things made the almost-broken parts broken.**

splinter

MB’s C32 ‘Flange Repair Kit’ from the EPC.

Part number is 112 090 00 44.

#55:

picture credit Mercedes-Benz®

I’ll let you know how it goes.

c32used

Keep us updated

splinter

MSRP is ~$980.

It has miraculously become more inaudible during each subsequent drive.

c32used

So give us details Splinter That good to know once warranty runs out.

splinter

I simply pulled it apart to inspect the friction material and its mating surface. It’s a straightforward procedure that has been shared previously by Brandon and others.

There was plenty of thickness remaining on the clutch lining itself. Sprayed it thoroughly with brake cleaner, although there was no evidence of untoward contamination. Cleaned the supercharger drive ‘pressure plate’ with some fine crocus cloth. Engagement and lockup is now a bit more stout which, imho, is a good thing. When that puppy locks up, it merely serves to reinforce the pleasure of the ODPS’d AMG experience. The chirp has been reduced to almost imperceptible levels, although it is still present. Recall that I'm hard of hearing, so ymmv.

That I’ve signed some depressingly large checks to the county, state, and feds this week has forced the accounting department to forego buying a new clutch straight away. All in due course.

Code3 Performance

Please don't buy a new clutch. I have been wanting to jump into this conversation, but held off until my new pulley was almost on the market. After all the r&d, I have a lot of insight on what the problem is exactly. Lets just say that we will be offering a pulley rebuild to address the problems. More on that later tonight, after I feed the 2 year old beast that calls me daddy

Code3 Performance

Here is a picture of the stock sc pulley cut in half, with the picture from the manual below it. Because the manual shows this complicated piece, I knew a stock pulley would have to give its life to prove the manual wrong.



As you can see right off the bat, not only do they look different, but there are components of the schematic that don't exist in the sc pulley. I think the picture from the manual looks more like the AC clutch than anything. As you can see from the real picture, there is nothing between the pulley grooves and the bearing, its straight steel.

With that out of the way, lets discuss the rest of the issues. The plate on the back is called an armature plate. It is not any kind of special friction surface, its just steel as well. It doesn't need to have any friction to it, the magnet is extremely strong, and once engaged, does not slip. There is no need to do anything to this piece.

The armature plate is attached to the pulley via three metal strips. The piece is then spaced away to create a spring effect with three spacers. Everything is riveted together with solid rivets.

The metal strips used in the OEM piece are just mild steel. What happens over time from repeated movement, is they start to conform to the spaced angle, and lose their "spring". Thus they allow the backplate to drag against the plate on the sc side, instead of pulling the armature plate back towards the pulley. Also, the rivets can start to give a little from wear, and contribute to this problem.

The pulley is spaced .3-.5mm away from the clutch. Thats not very much room. The spacers are installed on the shaft that runs through the pulley. You could add more spacers to move the pulley out further, but then you will have issues with the magnet not engaging because it can not pull the armature plate in far enough. You also run the risk of misaligning the belt, and putting to much wear on it.

Obviously the bearing goes bad over time as well. When it starts to fail, not only do you get noise, but you can also get movement. This can affect the issues above.

There was a TSB for the E55s to address the exact same issues we are having.

We will be offering rebuilt stock pulleys with a core deposit. The rebuilds will be a stock pulley that has been reconditioned with a new bearing, thrust washer, springs, and rivets. We use spring steel so that the springs will keep their form over time. Also we have the original NSK bearings.

splinter

Does increasing the clearance from specification reduce the likelihood of noise,
or perhaps offer some other performance benefit?







Thought some might enjoy reading MB’s position on remedying the noise:

ScottW911

The compressor squeak was the fall-back answer my SA gave to me when I complained about the noise, back when I warranty. I didn't buy it at all.

splinter

Noticed that the chirp tends to come and go as the months pass, much like one might hear from intermittently squeaky brakes.

With as many miles (<70K) as mine has accumulated, it should probably the least of my concerns. Nonetheless, I recently had the supercharger pulley’s clutch interface surface cross-hatch (Blanchard) ground on our local performance oriented machine shop’s Winona equipment. It’s the same procedure used to freshen and true the surface of used flywheels or cylinder heads during their renovation.

It’s continued to remain relatively silent thus far, even with my hearing aids amplifying at full steam. :-)

ohnoesaz

Well I guess I'll add for you guys...

My srt-6 has 33K miles. I have a huge chirp and jerk also. I've always had the jerk, but the chirp has only started with the cold weather. I bought the car used this year so this is my first winter with it.

It seems to go away after I drive for 20 minutes and everything gets hot.

It happens with the stock pulley, which seems to have a good bearing, as well as with my code3 pulley.

Tightening the pulley bolt, cleaning the clutch, and a few other things have not helped. Light belt dressing has not helped either, just in case this was belt-related.

Some have told me to use a larger pulley somewhere else, like replace an idler, to make up for the code3's smaller size but like I said it happens with the stock pulley too.

Thanks for sharing!

c32used

Funny cause after I recieved car on Friday now that its cold I hear a chirp like noise from the engine bay area but goes away like 5 minutes or less after car is on or driven is it possible I have the chirp? Thay is only sympton I have.

c32used

Hey JT the picture link doesn't work anymore can you post a pic again?

splinter

c32used

Thanks Splinter

The noise I heard is more of a clicking noise as to compare to a chirp and only at idle. When I apply gas its gone so I think its unrelated but gonna try and see if this solution does anything

ohnoesaz

Let me add to my description above for my 2005 srt-6...

The chirp and jerk are more like two seperate issues. I've always had a jerk, most likely from the tranny, and now in cold weather I have a chirp+jerk also most likely from the supercharger.

In fact when I'm driving at normal speed when its cold and press the pedal hard I can get a chirp then, even though the supercharger has been engaged since I started moving, suggesting this chirp is tranny related.

splinter

Old guy update. Just received a new hearing aid. Seems to work fine for business meetings.
The darn chirp has miraculously become much more prominent though.

Probably won’t wear it much when driving. Or at home.

Ring me sometime, ScottW911. Don’t I still owe you a lunch in Newport?

ScottW911

I'll call you very soon.

I'd trade that lunch for some of your time with a wrench under the hood of my car. It's due for some "splinter" style maintenance with plugs and fluids.

splinter

Don’t know if you’ve already installed your new supercharger pulley bearing. There’s nothing to it.
Even the Mrs. claims its erstwhile chirp has been effectively silenced.

DIY link

gt4awd

No press needed? Should go install the bearing that's been in my garage for a year... I have a sound similar to belt chirp when shifting WOT 1st/2nd gear. Recently started a month or so back. My supercharger pulley bearing is becoming louder every month.

ScottW911

Actually, my new bearing is sitting on my desk, in front of me, right now. Zeppelin's description seems easy. Your DIY makes me think I would prefer to bring some adult beverages over to your garage so you can show me how it's done.