Mr. CVE

Hi All,
It sounded like I had a noisy / bad supercharger bearing. so I investigated.
When the car is idling the blower clutch is not engaged, the noise is there.
turn car off, feel the actual blower shaft ( internal nut ) it feels fine.

But when you turn it, you can feel a scrape type noise against the blower pulley.

It is like a clutch finger is dragging against the plate.

The clutch still engages ( according to the traction light !! ) it's just noisy.

I have the protective cage around it. I am just wondering if this is the before signs before the clutch explodes.

Anyone had this before ?

And who sells them, I did a search and didn't come up with much.

new55

i like the fixed sc pulley (FSP) idea but it seems some have luck with it and others dont

Mr. CVE

I have an 84mm top and 178 bottom, don't really want any more boost.
As it is it need the throttle body upgrade.

latemodel21

When the bearing in the supercharger pulley is at the end of its life, it will make noise under these conditions you mentioned (SC NOT engaged). However, the noise you are describing could be made from the SC pulley pressure plate not fully dis-engaging (ie, lightly dragging on SC pulley magnet). If it is the plate dragging, it might not indicate that it is failing, but rather that the springs are not returning fully (and/or the pulley was not shimmed enough when installed). Aftermarket pulley clutch springs have not proven to be quite as "stable/robust" as OE in some cases ...

Just to be safe, you should inspect the (3) springs very closely (look for cracks at or near where they are riveted to the pulley).

you can take the SC belt off and pull the SC pulley forward a bit and then spin it by hand (should stop the noise if it is caused by the pressure plate dragging). Or you can take the scattershied off and check the pressure plate gap with a feeler gauge.

If you have never replaced the bearing, you may want to start shopping for one (you can usually find a good quality one at a decent price on Ebay)

hope that helps,
Chris

Mr. CVE

Thanks Chris,
That is exactly what it sounds like the plate dragging.
It was not always like this, only the last 10-15,000 miles.
Pulley has been on for 40,000 + miles.
The pressure plate springs....are they serviceable ?

latemodel21

serviceable? ... well, you need to quickly determine if one (of the 3) is failing (cracking).
Then, see if the they have all deformed uniformly. If they have, perhaps you can add a shim and be ok ?

The pressure plate springs have (in the past) been the Achilles heal of aftermarket pulleys. Early aftermarket pulleys were plagued with springs that were not in spec (in terms of material and/or thickness or process). They are not a service item (and not available as such). I had to have some made when I rebuilt the Pulley on my SL55.

hope that helps,
Chris

Mr. CVE

Thanks, so i need to pull the pulley off to check the individual springs ?

that's not so easy as i have to pull the pulley shield off.
actually even to check gap i need to do that, what feeler gauge gap should there be ?

latemodel21

you will need to pull the shield off to check the gap (S/B .35mm - .45mm).

you don't need to pull the shield off to inspect the springs for cracks.

pulling the shield off takes less time than it took for me to type this response : )

cheers,
Chris

Mr. CVE

okay, i just checked.
car was driven 3 hours a go so still warm
pulled belt off, turn the pulley and blower turns with it, and no noise.
took a lot of effort to break the clutch grab, but eventually did, then you can hear it drag loudly ( heavy drag )
pulled the shield off, which is a 1 minute job

tried to pull pulley forward to beak the grab, ended up wiggling the 2 faces with a fine blade. that broke the seal and now you can turn the pulley and only a little noise ( still grabs though.)
so there is zero clearance.
perhaps some shims will help.

Anyone know what diameter shims they are or sell me some ?
i try and pull the pulley in and out and there is no movement, or if there is, it is marginal, and tried to pull and push blower part itself and the same.

perhaps shimming it will help.
( it used to have a lot of red dust, back when i fitted the shield, that seems to have stopped. )
perhaps that part has worn away !

latemodel21

adding a shim may solve your problem. It seems unlikely that you will find anything off the shelf for this; you will need to find a source for oe shims (you would think anyone who sells pulleys could find these for you).

it might be time for a new pulley ?

Inspect your springs VERY carefully for cracks (as good quality springs should NOT have changed like this). once you add a shim, inspect it to see that the gap is uniform on all side (ie, rotate the pulley assy and check the gap in 3 places approx 120 degrees apart).



good luck,
Chris

Mr. CVE

will do,
the springs look dead flat, ie not bent forwards. And almost looks the springs could NOT go back to give clearance.
Almost like the blower shaft has come forwards. pulling back on the pulley itself also does NOT give clearance, I tried a 0.15 mm ( 0.004" ) feeler gauge and could only get it in one spot and then it still jammed up.

latemodel21

Are the 3 plastic spacers on your pulley still in place? On some aftermarket pulleys, when the springs have deformed a little, the springs fail to rebound to the point where the pressure plate is resting on the plastic spacers.
If your pressure plate is still resting (or nearly resting) on the spacers, then it would suggest that the gap may have been on the small side when you originally installed the pulley, and another shim (or shims) is in order.
If the gap(s) is large between the pressure plate and the spacers (or the spacers have disappeared), then it would suggest that the springs are not fully rebounding and brings their composition into question (and/or could indicate that the installed-gap was too great and the springs have been routinely cycled a bit past their yield point causing them to deform).

Cheers,
Chris

Mr. CVE

Turns out it was the supercharger pulley bearing.
Thanks to Toadster for posting one to me over the drink.
fitted it today and it's quiet as, can finally hear the noisy injectors again !
Oh and thanks to EVERYONE who helped. i noticed the clutch faces are not flat, but i did not machine it as i was unable to machine the supercharger face.

GatorMB

To add Mr Latemodel 21 very useful posts.

The faces of the Clutch plate and the idle pulley are much like a brake rotor and pad friction wise with the exception of being metal on metal.

After years of engage and disengage the surfaces wear to be expected. When the clutch return spring rivets start failing the scraping occurs. The looseness in the idle pulley bearing increases causing further wear on the clutch plate.

To inspect the plate surface it must be removed and normally the return spring rivets are close to fail. The scrape sound must be fixed fast.

There is a brother E55 member who sells a scatter shield which saves the engine from breakdown when they fail.

Ebay item # 142133755017

A quick shim might extend the life of the clutch.

Cheers, Gator