Worn coupling sound in supercharger?

Jogi

Registered User
What kind of sound worn coupling/coupler in supercharger gives?
I have MPII supercharger that is driven about 4-5000 miles (+10% smaller pulley..)
It has been giving slight sound kinda like marbles rolling inside supercharger at idle.. noise goes away as revs go up... say few hundred rpm's. (or I can't hear it anymore)

Pulley in snout feels solid without any feeling that could indicate bearing failure..

Should I worry about this?

edit: I inspected supercharger oil month or 2 ago... there was guite lot of metal "dust" in it, so something is going on. I removed most of the oil and replaced it with clean one. Has worn coupler done this? (I have no idea if MPII has "rubber" or spring loaded version of coupler.)
 
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A worn coupler will make the marble sound and it will go away when you throttle up.....

If you take the top off your blower, you can hold the rotors and turn the pulley back and forth to see how much play you have in the coupling....
 
Also note that this is the right way to check it for a standard m90. The MP units have play to begin with. With the MPII you can turn the pulley a good ways before it intiates unlike the stock units.

Just something to keep in mind.

-Tim
 
If you put in a solid coupler the slop goes away. Even with the MP products.I have one of the Black solid couplers , I think from Wynn and they are excellent.
I really learned alot about the blower taking the thing apart and rebuilding the snout these things are very stout. I would replace the stock snout seal with a Chicago rawhide dual Viton seal and a snap ring with OD of 1 7/8 . this as a very cheap mod that give piece of mind, I know my snout seal will not be leaking.
 
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Here's a little story related to this topic I thought I'd share.:) Way back when (about 8 or 9 years ago), when Magnuson Products was about the only game around for blower upgrades I sent them the blower off my 95 which had around 35,000 miles on it at the time to have it S-modeled. When I got it back and installed it, it ratteled like hell at idle right from the get so I called Magnusons and told them this thing sounds like a bearing is going out or something and it didn't sound right. They said send it back and they would go through it and check everthing out so I sent it back. About a week later I get a call from them and they tell me they checked it all out and there is nothing wrong with it...everything is fine. They sent it back to me, I reinstalled it and nothing changed, it still rattled like hell at idle. This same blower is now on my 94 and sounds just like it did back then, no better of course but no worse either and still makes just as much boost as it did back then. 15 PSI on a really cool day with stock pulley and peg city any time with a 5% OD pulley. I have been planning on fixing it now that I know about the coupler problems associated with blower rattle but I just never seem to get around to it.
 
442guy said:
If you put in a solid coupler the slop goes away. Even with the MP products.I have one of the Black solid couplers , I think from Wynn and they are excellent.
I really learned alot about the blower taking the thing apart and rebuilding the snout these things are very stout. I would replace the stock snout seal with a Chicago rawhide dual Viton seal and a snap ring with OD of 1 7/8 . this as a very cheap mod that give piece of mind, I know my snout seal will not be leaking.
Thanks! I still have the same one I installed in Lola's blower over a year ago, been beatin' the heck out've it ever since and not one sign of wear, sure appreciate the endorsement!

'bird
 
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