Supercharger coupler

[Maylar]

So, the supercharger on my 99 Ultra is making nasty noises. What parts will I have to have on hand to make a repair? I bought a "coupler kit" a couple years ago in anticipation of doing this, but haven't even opened the box yet. I know I need oil (4 oz?) but what about gaskets or other misc items?

I can see the pulley wobbling a bit - is there a bearing in there?

 

[MelsRegal]

are you sure you wouldnt be better off replacing it with a rebuilt unit?
you are approaching this project without a shop manual?

 

[pila80]

It the pulley is actually wobbling, there may be more wrong than just a noisy plastic coupling . I've had mine off the engine twice, once for the coupling & once for a leaky intake gasket. I did replace the oil seal behind the pulley though...

 

[Drakito]

If it is wobbling you will need the snout rebuilt. I know ZZP, Intense, and the Supercharger store sell rebuilt ones, I can rebuild them as well, but they charge not much in labor compared to buying all the parts and shipping etc. I end up being ALMOST the same price.

 

[HotZ28]

We need a clear definition of what the "wobbling" is! Is it on the clock scale 12-6, or is it vibrating up and down? There is only two bearings in the snout front/back, with a seal in the front. I have also rebuilt many M90's including the needle bearings in the rear of the rotors. Usually the snout bearings do not fail, unless the oil was low.

 

[Maylar]

If it is wobbling you will need the snout rebuilt. I know ZZP, Intense, and the Supercharger store sell rebuilt ones, I can rebuild them as well, but they charge not much in labor compared to buying all the parts and shipping etc. I end up being ALMOST the same price.

Thanks very much for that. I checked the ZZP web site and they have a video / audio clip of the M90 snout making the same noises as mine does. It's not just a rattle at idle, it's truly a nasty noise and they claim it's from a bad rotor pack. In the interest of time (this is my daily driver) I think I'm going to order a rebuilt snout from them.

I do have the factory service manual, and the only info on the supercharger is how to replace it as a unit.

 

[Drakito]

It's fairly simple.
Take out the oil fill plug on the snout.
Drain the fluid with a syringe, gag on the smell.
Remove the belt.
Take out the bolts on the snout.
Lightly tap the snout with a rubber mallet.
More fluid will drain out.
Pull the snout off. Remove the coupler and chuck it in the garbage.
Spin the rotors by hand and see if you still have noise.
No Noise? Put the new coupler on.
Put anaerobic sealant on the snout.
Bolt the snout on, 17ftlbs torque on the bolts, crisscross pattern.
Refill with new supercharger oil, usually uses 2 full bottles if you pulled the snout.
Reconnect the belt.

If for whatever reason it really is the rotors, you can leave the supercharger disconnected and your engine will function like a non supercharged one. The computer automatically reduces fuel for the no boost and you will be fine.

 

[Maylar]

Thanks. I wondered about just disconnecting the belt. I had to replace it once and I remember having to remove a motor mount. Can the belt be "disconnected" and tied up without doing that? A new snout will be here Saturday but it'd be great to be able to drive it 'till then.

 

[The Avenue]

Yeah, the SC belt has a tensioner just like the serpentine belt does. Look for a pulley that has a torx head.

 

[Maylar]

Spent the day Saturday replacing the snout with one I got from eBay
Rebuilt Snout

Went well except for the top 2 studs that attach the snout and wiring loom. One had seized to the point where the 10 mm hex was gonna get rounded off before it'd come out. My nephew brought over something he called a "turbo socket" that digs into the bolt head. Gotta get me a set of those.

The snout was toast - and totally dry of oil. Dunno how, I've never seen any oil under it. Nobody ever told me that's a maintenance item. I've had the car to the local dealer a couple times in the last few years, you'd think they would have checked. Live and learn.

 

[Drakito]

Yeah, it's a "sealed lifetime" system, so no one ever checks them, not even the dealer. It's not on the service life checklist either.
I have found they make it about 150-160K miles and 10-12 years before oil has evaporated or slowly leaked out.
The couplers usually start rattling long before the oil is gone as the stock coupler gets stress cracks from the drive pins, radiating outwards. They can be cracked as soon as 10k miles. As they are used longer and longer the cracks open up and gaps appear, causing more and more noise as the pins now can rock more in their bores. I have seen a failed coupler as well where it cracked out large portions around the drive pins.