How to replace an M90 snout coupler
Writeup by Will "Overkill" Rishworth of OQCGP
The day was April 19 2002, a Friday, the day after my college semester had end and I was free for 3 weeks. I was happy to have time off so I decided to relax and enjoy by working on my car, the plugs and wires had to be changed. Half way into the procedure of changing the back plugs, I realized that the blower snout may be able to be taken off quick easily. My blower had 229,000kms on it, while in good shape it rattled at idle and I had a new coupler in my basement which was supposed to fix the problem. With a call to crazy Alex to bring some oil for the supercharger, I decided to attempt the snout removal. Here's what happened:
Holding the blower in my left hand, I could rattle the coupler on its pegs. According to Mike Wood this is what happens, sure enough he had his old coupler with him which we slapped on and rattled on the pegs.
Update April 1, 2003
I'm finally finishing the installation instructions and updating pics on a new coupler which I'm now using
Here's the new coupler I'm using, its a ZZP unit. I've gone through 2 stock couplers now, even my new coupler last year started rattling on the pegs after only a few months. This time, ZZP had a new coupler to use this time around. I was fairly impressed with it, it seems more bulky, a harder compound and will hopefully withstand oil a lot better than the black composite material of the factory unit.
This time the supercharger came off for a cleaning so I'll show some pictures from this but its the same instructions for if its on the car :) First step of putting everything back together was to take some brake cleaner and spray down the rotors and behind to get rid of all the black guck, afterwards it was all nice and clean. Now lets put that coupler on the gear pegs!
The new coupler was purchased from Zooomer for $40US with shipping. I lubed the pegs with some simple s/c oil to help slide her home. The holes with the lip on the outside go towards the pegs that're about to slide through the holes, notice the holes left for the snout pegs for the correct alignment. Once pressed on it was a nice tight fit, no looseness at all. I then took the brake cleaner and cleaned out the inside of the s/c snout, get rid of the nastiness! Once clean, it was ready for some sealer. For this I used a normal gasket maker or RTV silicone, something to create a seal between the metal surfaces since after all there's oil being held in here! Be nice and thin with the sealer, no need for a big bead that's gonna go splat, just a nice thin line all around. Also put some oil on the pegs on the snout. Now to reattach the snout to the rest of the s/c.
Peering between the snout and the rotor housing, I lined up the pegs to the holes on the coupler. Once I got the pegs started, I gentley push on the snout housing and it starts to slide on. To line up the snout with its mounting tabs, on two of the bolt holes there are protrusion. Once lined up the snout will push right into place. Now time for the bolts and to start tightening them snug, for the final tightening use about 15ftlbs on your torque wrench. If you're not sure what this is, give it your best guess. Remember that you're screwing into an aluminum housing so don't reaf on the bolts! Just a nice snug bolt is all that's needed. I wiped off sealer that came out the sides with a rag, I'm a maid I know. You may now fill the snout with your favorite s/c oil, which in most cases should be genuine GM oil :) you'll need 3 bottles of that stuff, fill it right up to the bottom of the threads on the filler plug! 2 bottles will come close enough but I suggest 3 to go all the way and keep the rest for whenever you need it next.
From there installation is the reverse of removal. Pop the alternator back on, put the belts back on, reconnect the fuse box, and I was back to where I started from. I finished my plug and wires change plus a thermostat and started the car up to reveal no leaks, misfires or other abnormalities. Sometimes I even think I know what I'm doing!