Question(s) for those who've rebuilt their SN's...

[Michael]

I believe the tips were hitting the scroll housing because the ball carrier was so badly damaged that the balls were no longer riding true on the races. Thus causing the impeller shaft to move at the mercy of the uncontrolled balls - moving in and out against the scroll housing.

Any other theories?

What do the races look like Michael?

You might be right... I didn't consider that it may very well have been because the ball carrier was so badly damaged that it allowed the impeller/impeller shaft assembly to move forward/aft enough to cause the damage. Makes sense, especially considering that the damage to the back side of the impeller itself is relatively minor.

Here's a photo of the drive balls themselves when I pulled them from the supercharger (those eagle-eyed readers will notice there are only four balls, not five... the fifth ball was so badly mangled I just threw it away). These are gouged pretty badly to say the least.



As for the races, here's some photos of those. I haven't removed the one race from the flange yet, but I'll do that soon. Interestingly, aside from a slight discoloration, they races actually look to be in really good shape, not unlike the impeller shaft itself. Raises the question: should I get new ones or do you guys thing I can reuse these?







BTW, I stopped by a bearing shop yesterday and order a new set of ball bearings. They suggested SKF; the guy at the bearing shop said that the Nachi bearings that came with the supercharger were "good", but that SKF were "the best". I trust his judgement seeing as bearing are his business (he did ask what they were going to be used for and the intended RPM, etc...). He had to order them and they should be in tomorrow, so I'll post photos and info of those when I go pick them up.

I think a call to Paradise Wheels will definitely be in order very very soon. Lots of new 'goodies' to put on order in preparation for the rebuild.

[Michael]

Just removed the rear seal from the scroll housing. Thought I would share how I did it. I was under the impression that removing this seal would require destroyed it, and I didn't want to do that. I was convinced there was a less destructive way to removing this seal.

Below is a photo of the rear seal still installed in the scroll housing of my SN89 (looking from the impeller side):



The procedure was simple with some easy to find tools in the form of a 27mm-1/2" drive socket and a rubber mallet:



I placed the socket (drive-side up) over the rear seal:





I found that a 27mm-1/2" drive socket fits perfectly in between the rubber portion of the seal and the scroll housing itself; any smaller and the rubber seal would suffer damage during removal, any larger and the socket wouldn't fit through the scroll housing hole. I used a 6-point socket, but a 12-point would have provided even more clearance between the socket and the rubber seal. Since this seal is going to be replaced anyway that's not a big deal in this case:



Then, using the rubber mallet, I tapped the socket firmly until the seal came out:



Here's a shot of the seal, now removed from the scroll housing:



The seal itself looks to be in great shape. It's too bad I can't reuse it - my understanding is that this is an expensive seal to buy, and the only source is Paradise Wheels:





The scroll housing with the seal removed:



A closer look at the impeller side; you can see the scoring from the impeller making contact with the housing. The marks look worse in these photos than they really are, so I doubt I'll have to replace the housing itself:





The inside of the scroll housing. You can see where the rear seal was installed:



Evidence of hair-line cracks... hmmm... probably from years of heat-cycling? Fortunately, these cracks don't go all the way through to the other side, otherwise Paradise Wheels would be getting a MUCH bigger order from me than I originally thought.





Next, I'll be removing the scroll cover locating pins. Stay tuned, there's more to come...

[Michael]

Locating pins - removed!

This thing is coming apart too easily... I'm starting to think that something is going to go wrong soon... LOL!!! Although I hope not.

The two locating pins I'm talking about are shown below. They're used to locate the scroll cover to the scroll housing itself:



Before removing the pins, I measured how much they protruded from the scroll housing and the scroll cover's mating surface. That way I'll be sure to reinstall them to the same depth. I checked both pins and each one sits about 1/4" above the scroll housing's mating surface.



The tools used to remove the pins were a no-brainer - my trusty rubber mallet, a thin punch, and a scrap piece of wood:



From here, the rest is pretty easy. I rested the scroll housing on the piece of wood, put the end of the punch on the pin, and tapped until the pin came out (repeating this process for both pins, of course):



Both pins removed:



It's easy to see which holes these pins came from as they're the only ones that don't have threads:





The scroll housing is now completely disassembled. Next stop for this part: The Buffer! I'm going to give this blower a 5-star mirror finish before putting it all back together. I'll outline that in later posts.



Next up... the front seal. Stay tuned... more to come.

[Michael]

Just as I had predicted, something was bound to go wrong. The front oil seal doesn't seem to want to come out.

As usual, I pulled together a simple collection of tools: my trusty rubber mallet and an old piece of wood (from a piece of furniture we no longer own).



The piece of wood is (virtually) the perfect diameter, making good contact with the oil seal's metal surface, while being small enough to fit through the oil casing's hole:



I firmly tapped on the piece of wood expecting to see the seal start moving down the case and eventually fall out:



Unfortunately, the seal only moved a very small amount and the seal itself has become somewhat bent:



I was going try using a propane torch to heat the casing where the oil seal is installed, however I thought I would pose the question on here first: How do you guys suggest I remove this seal?

[Michael]

Feeling a bit dejected by not being able to remove the front seal, I decided to tackle a much easier job: the boost gauge outlet hole (or at least what I believe is the boost gauge outlet hole).



All that's needed is a 3/16" allen key and a little muscle:





With the allen head plug removed, the scroll cover is now completely disassembled:







Closer inspection reveals what may have been some minor repair work... possibly done shortly after this part was cast...? Looks like it as there's no appearance of a crack on the other side.





Otherwise, everything looks pretty good here too. Part number two is now ready for the buffer!

And now, back to figuring out how to take out that front seal! Once I get that front oil seal out, I'll be ready to buff everything back to a mirror-like finish and I'll start ordering all the replacement pieces I'll need from Paradise Wheels.

[Michael]

Been a little while since I posted an update.

I've finally managed to get the front seal out of the SN89's oil case. Unfortunately, I couldn't get it out in once piece; I essentially had to destroy it to get it out.

Here's some photos of the seal after I removed it from the case:







Fortunately, the oil case itself wasn't damaged when I removed the seal. Here's some photos of the oil case:







Now that the blower has been completely disassembled, it's time to start the rebuild.

I called Paradise Wheels yesterday afternoon and ordered a complete rebuild kit, which includes all the wear items inside the blower, including ball carrier, bearings, races, impeller shaft, shims, pins, balls, seals, etc... For it's cost ($450), it makes no sense to order all the parts individually. I also ordered an H.O. impeller too; I figure since I'm going through the effort of rebuilding the blower, I might as well replace the stock impeller with the H.O. version while I'm at it. I got the H.O. impeller for $150.

While I'm waiting for all the replacement parts to arrive, I'm going to begin polishing the blower itself. Hopefully, by the time the parts arrive I'll have the blower's finish back to it's original mirror-like finish. I'll do my best to document the polishing process.

[winfred]

just did mine and you can only get it so shiny, i used a bench buffer


the back plate is a bit rough to polish so i powdercoated it wet black




did a little mild polishing on the new ho impeller as its not real smooth, and cleaned up the casting of the case where it was really rough down in the groove with a wire brush on a dremmel

[Michael]

Woo Hoo! My rebuild kit from Paradise Wheels just arrived!

I can't believe the amount of parts that are included: races, balls, carrier, sleeve, seals, pins, impeller bolt, 'O'-Rings, shims, impeller shaft... it even includes an original "Paxton Superchargers" sticker for the blower casing too! It's like Christmas!!!



The only items that weren't included with my order were the roller bearings. I picked up a set of FAG bearings from a local bearing store a couple of weeks ago:





I added an upgraded H.O. impeller to my order as well. I figured I'm going through the trouble of rebuilding the blower, so I might as well do it now :happy: :



The only other item that I picked up that isn't normally part of the rebuild kit was a VR-4 Belleville washer. This isn't for the SN89 though... :teeth: :



I'm still in the process of polishing the blower's oil case, scroll, and scroll cover. Hopefully I'll have that done sometime next week. But for now, it looks like I have all the parts I'm going to need in order to start the rebuild once everything is polished up.

[ceetwarrior]

"FAG" lol !!!!!!!!!! Korea doesn't have a clue

[ceetwarrior]

I just rebuilt mine. Got all the goodies from Paradise Wheels as well.

Just put it back together, It's very smooth but takes alot of muscle to turn, is that how they are supposed to be?

[JPJP]

FAG is a high end bearing.

There is a specific rotational torque value you should be shooting for. Paradise Wheels should have given you that when you bought the kit.

[winfred]

High 20s low 30s in the inch pound range. I did all of my testing with the roll pin out so I could easily pop the race out and add or subtract shims and when I finally got it right and installed the pin it was too tight till I popped the race and seated it, the pin was keeping the race from moving on that side and it cocked, after that it was back to the as tested reading on my dial type torque wrench

[ceetwarrior]

Thanks guys. I don't have one of those tools, but I think I know who does. So if it's too tight, which/where shims do I add to loosen it up? It's the ones under the big bellview washer, I can't remember how it looks...

[winfred]

Remove the ones under the bellview washer to loosen

Thanks guys. I don't have one of those tools, but I think I know who does. So if it's too tight, which/where shims do I add to loosen it up? It's the ones under the big bellview washer, I can't remember how it looks...

[Charged87GTA]

hey, really likeing where this thread is goin, doin a great job with the pics and descriptions.

ill be watching for updates

ive had my 89 sitting on a shelf for close to 3 years now. started making a weird almost buzzing noise, tor it appart and found the impeller shaft had a small nick in it. everything else looked perfect.

figured on sending it out for a rebuild, but after reading through this thread i think i may try it myself


also the drive balls look un harmed, took the unit off immeditely after i heard any noise, anyone think it would be a bad idea just to replace the impeller shaft and save myself 300 bucks?