Hi all,

I removed my supercharger belt today due to a noise, but I notice that the pulley at the supercharger nose spins freely if I rotate it with my hand. Is that pulley at the supercharger nose suppose to rotate freely like this OR not? I remember coming across a post, which I can no longer find, that I believe I see the poster stating it should not rotate freely more than 1/8 of the way around. Unless, of course, I may have misunderstood the post. Any idea or suggestion what I need to do. Thanks much

 

It should turn fully and reasonably freely by hand.

 

It would be bad if it didn't rotate freely. I think what they meant is that you shouldn't be able to feel too much play in either direction before the gears start to turn. Can you feel a small spot where there's no resistance, and then you feel the gears take up? That play shouldn't be too much. I have maybe 1/4" at the rim of the pulley, almost undetectable. Some people have reported like 1/4 turn if the joint is worn! Also when you turn the pulley, it should feel reasonably smooth.

 

By "play", I'm assuming you're talking about if the pulley wobbles or if it pulls out or not?

 

You'll feel some resistance from the rotors, but it will turn freely in either direction by hand. The play he's referring to is in the internal coupler that connects the pulley to the rotors. Pulley play will be in the bearing, and is checked by linearly pulling/pushing on the pulley laterally relative to the snout, without any rotation of the pulley. If the bearing has play this will show up there. Coupler play will show up when you rotate the pulley, where there will be a small "dead zone" before the resistance of the rotors turning starts. Neither is super common, but it's also not unheard of.

 

I suppose the pulley is working properly then. Thanks all for the help.

Next question is: The belt is no longer in good shape, I can see cracks throughout the belt. I will be replacing it. I called my local jag dealership and they asked if I had the metal or plastic idler pulley and the tag for the belt is $111 before tax (assuming it's the metal pulley. I haven't asked about the plastic yet, but will do it tomorrow once I find out exactly what I have). I think I may just buy an aftermarket belt, but how does the idler pulley determine what belt I should get and if so what type of belt should I be getting based on whether the idler pulley on my car is plastic or metal? It's cheaper at an auto parts store, but their system doesn't signify whether it is suited for a plastic or metal idler pulley. Any suggests? Thanks in advance.

 

I just replaced one and the GATES GREEN STRIPE fits fine on the smooth pulley version. (single sided belt)

I think it was K080514 GREEN STRIPE for around $50.

bob gauff

 

At some point, they changed from a belt that is ribbed on one side, to one that is ribbed on both. If you have the both, the idler pulley has ribs too. If you have the one sided, the idler pulley is smooth. I suspect that's why the parts guy was asking.

You just need to get the right belt, one side or double.

 

Thanks much guys for all your help.