Supercharger pulley/shaft "issues"

ChaseZ

Been trying to chase down a hiss, which I figured was a vacuum leak. It was coming from somewhere around the blower which I thought was odd but whatever. Went around everything including the manifold with carb cleaner to see if I could nail it down and nothing.

Gave it a bit of rpm to see if the hiss increased or not and it didn't. So was checking we'll more or less everything in that area. Found the belt slipped a rib on the jackshaft pulley and loosened off the tensioner to adjust it - which is when I found this play on the blower pulley that I'm pretty sure isn't supposed to be there lol (but feel free to correct me if I'm wrong). There doesn't seem to be any beRing noise out of the norm, they are noisy anyways. It still spins pretty smooth but sure seems like it isn't engaging with the impeller to do make the world go round. So not sure if this indicates a shaft problem or what. It doesn't seem to catch, grind or anything else regardless if it is pushed in or pulled out. Surely this can't be normal right? Wanted to float this past you guys before I pull it all apart for inspection.

ChaseZ

And I haven't had that pulley off, to anticipate the question.

GTRphil

thats not normal, it should not move in and out like that

ChaseZ

Trying to find any info on this and not having much luck. Sounds like Vortech sells a retainer kit which has a key. Perhaps this key is out or improper in some fashion? It looks simple enough, that part anyways. Trying to get the pulley off, unsuccessfully. Tried strap wrench around the pulley but the bolt is too tight and it slips before I can crack the bolt. It's only supposed to be 35lbft so somebody just have reeled it on there. Any other ideas how to get the bolt off? I'll have to heat the pulley a bit to remove it but need to get to that part first and want to use as little heat as possible since there are lots of bearings to be cautious of.

ChaseZ

Even stranger I went back an hour or so later and it wouldn't do it. I suppose it was a bit warm before and now cool. Just guessing

SouthArk370Z

I don't have any experience with centrifugal blowers but have worked on a lot of liquid cent pumps. If that shaft is attached to the impeller, it shouldn't have any axial movement. Axial movement will affect the bowl-to-impeller clearance causing a loss of efficiency or contact between the two parts.

The self-healing thing has me confused. Maybe a cracked retainer?

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ChaseZ

Wish I was convinced it was actually self-healed.

At the very least it's going to have to come apart for inspection and see what's up. It's connected to the impeller via gears, yes.

SouthArk370Z

My guess is that when the belt shifted it placed a high axial load on the ball bearings shown in the pic. This pushed the bearings out of position on the shaft (the inner races were loose on the shaft). This allowed the in-out movement of the shaft when you tugged on it. Putting the belt back in place seated the bearings just enough that a slight tug won't separate them. A good yank may break them apart again. Like I said, just a guess.

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Jayhovah

Come to the dark side, Chase.... The turbos are waiting for you along with 70 virgins that are magically good in bed despite inexperience.

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ChaseZ

I'm just a little invested in supercharger at this point. If money were no object then I'd have went twins from the get go, but well it is. No virgins for me I suppose. Besides, I'm not interested in blowing up my supercharger or myself!

cooltoy

That sounds a lot like the pitch ISIS uses.

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ChaseZ

Vortech saw the videos and told me that is a normal amount of movement however it shouldn't be that easy to move so something could be wrong internally.

Not really the definitive response I was looking for. Heck there are like 15 parts to these things you'd think they would know right away what it is from the symptoms. Guess not. I hate the idea of shipping this thing all the way down to Cali with a blank check for 3-5 weeks. I'll check with a local Vortech dealer I know and see if they have other ideas or can just do it there perhaps first. Nothing rolls out of their shop without a supercharger so they must know these things inside and out - then again I just assumed that very thing from the actual manufacturer didn't I lol

TopgunZ

Well, if you dont have the SI impeller then this is a good time to do that if you end up sending it down there. Its better to run the Si impeller and 8psi pulley if you are worried about cooling.

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ChaseZ

It does have the si impeller. I would consider the ceramic hybrid bearings to bring it up to 63k rpm though.

I checked with a supercharger rebuild shop and sent him the same videos the Vortech tech saw. Here was his response. I believe I posted Vortech assessment earlier.

Guess who is getting my business lol

BHunts

Glad you were able to find someone that could pick up on the issue so easily for you. Is he local to you or will you still have to ship it out?