Blower rebuild instructions

kenewagner

Registered User
I have a complete rebuild kit for my Eaton M90. I did not receive detailed instructions for installing all the seals & bearings. I have replace some of the seals and bearings in a M90 before but not a complete replace everything including the rotors. I am sure I will get it done but instructions always help get me by any sticking parts in the rebuild. Any help would be appriciated. Thanks.
 
Do you need the ones I used? Or more specific? I can dig those up... Are you talking the front rotor bearings too?
 
007_SuperCoupe said:
Do you need the ones I used? Or more specific? I can dig those up... Are you talking the front rotor bearings too?

I read in other threads that the only one that has the seals for the rotor pack is Magnum Powers. I still have to check the kit I have and see if they were included. I got the kit from Wynn. I have the rotors and the front end plate as a unit. I am concerned that the seal might not be OK as it is not a brand new rotor pack. I could use a copy of your instructions. Is there any way you could fax them to me? If so the number is 402 341-3202. Thanks for your reply Sam, I appriciate your help
 
kenewagner said:
I have a complete rebuild kit for my Eaton M90. I did not receive detailed instructions for installing all the seals & bearings. I have replace some of the seals and bearings in a M90 before but not a complete replace everything including the rotors. I am sure I will get it done but instructions always help get me by any sticking parts in the rebuild. Any help would be appriciated. Thanks.
ouch, that hurt!

The way I type it would take 2 weeks to do up a set of instructions and it would take you 3 days to read 'em. By the way, the seals in the blue/black boxes are the rotor seals.

I have a super-simple "trick" for gettin' the gears off the rotors, so easy my cat can do it but it's impossible to explain in type. Gonna be outa pocket until Monday mornin' but maybe someone here can help.

"I read in other threads that the only one that has the seals for the rotor pack is Magnum Powers."
Magnum Powers sells a rebuild kit? Since when?

'bird
 
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tbird88 said:
ouch, that hurt!

The way I type it would take 2 weeks to do up a set of instructions and it would take you 3 days to read 'em. By the way, the seals in the blue/black boxes are the rotor seals.

I have a super-simple "trick" for gettin' the gears off the rotors, so easy my cat can do it but it's impossible to explain in type. Gonna be outa pocket until Monday mornin' but maybe someone here can help.

"I read in other threads that the only one that has the seals for the rotor pack is Magnum Powers."
Magnum Powers sells a rebuild kit? Since when?

'bird

Wynn: Sorry, didnt intend to inply I was shorted in any way. Everything I have bought from you has been great and you have a totally satisfied customer here. I started looking at threads concerning the rotor pack and it seemed to be complicated. The threads said Magnum Powers were the only ones that had the rotor pack seals and that they did not sell them seperately, only through a rebuild of the supercharger its self. I bought these teflon coated rotors and want to get the install right the first time I wont be rebuilding the SC untill next week so I am not under the gun
 
i am in the same process you are. how to get the shaft out of the front and to remove the rotors. Where did you get the teflon coated rotors at, or did you have it done? what did the inside of your case look like mine is pretty rough. next month i am plannin on gettin a rebuild kit from wynn,
 
rzimmerl said:
i am in the same process you are. how to get the shaft out of the front and to remove the rotors. Where did you get the teflon coated rotors at, or did you have it done? what did the inside of your case look like mine is pretty rough. next month i am plannin on gettin a rebuild kit from wynn,

I got the teflon coated rotors from a GP web site. They are still in the front plate so I have not removed them. I hope to call and get ahold of wynn Monday to get his way of removing so I can have the rebuild be a through job. My case had a few scratches in it. If you get a rebuild kit from Wynn you wont be disappointe he's a standup guy
 
kenewagner said:
I got the teflon coated rotors from a GP web site. They are still in the front plate so I have not removed them. I hope to call and get ahold of wynn Monday to get his way of removing so I can have the rebuild be a through job. My case had a few scratches in it. If you get a rebuild kit from Wynn you wont be disappointe he's a standup guy
Due to obligations...girlfriend is sellin' jewelry at the fleamarket this weekend and yours truly HAS to sit there with her and endure all this girly-stuff...please don't tell anyone, especially j57ltr!

Let's see if I can keep it simple. If you don't understand this completely then please don't try it. Like I said, I'm terrible at typin' so I don't really explain myself well at all. Probably confuse the heck out've you on the phone too, ask any Canadian.

Make a mark on the rear of the rotor pins where they stick out of the back of the rotors. A fine point sharpie works great for this.
Take a steel plate (3/4" thick will do) that measures 6"x8" and drill two 3/4" dia. holes in it that line up with the rear pins on the rotors.
Stand the rotor pack on end, gears facing up, rotors sittin' on the plate with the rear pins facing down in the holes.
As a buffer between the ram and the rotor pin you want to press, set a small chunk of 1/2" round bar stock on top of one of the rotor pins. Make sure this little chunk is cut nice and straight/square/etc. It's a sacrificial item but needs to be true.
Come down with the ram on the chunk/rotor pin and press it until you get the initial break/snap/crackle/pop/creak. Technically, what you are tryin' to do in this stage is to press the rotor pin down through the rotor. Press it down ONLY enuff to get the initial "pop", 1/32" is plenty.
Do the same procedure again with the other rotor/pin.
You now have the initial break done between the rotor pin and the gear.
You've also loosened the hold that the inner race of the front rotor bearing had on the pin.

Now...Take the plate with holes out from under the rotor pack.
Set the edges of the rotor bearing plate on some blocks and let the rotors hang free.
Lift the rotor pack up a tad and place various types/shapes of steel chunks/blocks up under the the rotor plate.
Using your best judgement, locate these pieces into the nooks and crannies of the rotor lobes to where they'll provide a decent surface for the bearing plate to rest on.
Grab your little piece of 1/2" barstock and put it back between the ram and pin.
Have a bud ready to catch the rotor and start pressing.
If you have the bearing plate supported halfway decent at all then you shouldn't have a thing to worry about at this stage. Should only take a few hundred pounds of pressure and the rotor will start droppin'.

note to your helper: CATCH THE ROTOR!

Repeat for the other rotor.

Move everything off the press and take that rotor and set it up in the press with the gear end facing down in one of the holes in the 3/4" steel plate.
Usin' your little chunk, press the pin back through the rotor that tiny 1/32" that you moved it in the first stage.
Watch the mark you made with the sharpie so you know when to stop. This will restore the pin in its original location within the rotor.

Do this NOW, do NOT wait until later.

Repeat for the other rotor.


Fingers are sore from typin', I'll do my best to press some rotors Monday and take pics of the process. It ain't magic, just common sense and a little bit've logic.

'bird

kenewagner - my mistake, many thanks for the compliment :)
 
tbird88 said:
Due to obligations...girlfriend is sellin' jewelry at the fleamarket this weekend and yours truly HAS to sit there with her and endure all this girly-stuff...please don't tell anyone, especially j57ltr!

Let's see if I can keep it simple. If you don't understand this completely then please don't try it. Like I said, I'm terrible at typin' so I don't really explain myself well at all. Probably confuse the heck out've you on the phone too, ask any Canadian.

Make a mark on the rear of the rotor pins where they stick out of the back of the rotors. A fine point sharpie works great for this.
Take a steel plate (3/4" thick will do) that measures 6"x8" and drill two 3/4" dia. holes in it that line up with the rear pins on the rotors.
Stand the rotor pack on end, gears facing up, rotors sittin' on the plate with the rear pins facing down in the holes.
As a buffer between the ram and the rotor pin you want to press, set a small chunk of 1/2" round bar stock on top of one of the rotor pins. Make sure this little chunk is cut nice and straight/square/etc. It's a sacrificial item but needs to be true.
Come down with the ram on the chunk/rotor pin and press it until you get the initial break/snap/crackle/pop/creak. Technically, what you are tryin' to do in this stage is to press the rotor pin down through the rotor. Press it down ONLY enuff to get the initial "pop", 1/32" is plenty.
Do the same procedure again with the other rotor/pin.
You now have the initial break done between the rotor pin and the gear.
You've also loosened the hold that the inner race of the front rotor bearing had on the pin.

Now...Take the plate with holes out from under the rotor pack.
Set the edges of the rotor bearing plate on some blocks and let the rotors hang free.
Lift the rotor pack up a tad and place various types/shapes of steel chunks/blocks up under the the rotor plate.
Using your best judgement, locate these pieces into the nooks and crannies of the rotor lobes to where they'll provide a decent surface for the bearing plate to rest on.
Grab your little piece of 1/2" barstock and put it back between the ram and pin.
Have a bud ready to catch the rotor and start pressing.
If you have the bearing plate supported halfway decent at all then you shouldn't have a thing to worry about at this stage. Should only take a few hundred pounds of pressure and the rotor will start droppin'.

note to your helper: CATCH THE ROTOR!

Repeat for the other rotor.

Move everything off the press and take that rotor and set it up in the press with the gear end facing down in one of the holes in the 3/4" steel plate.
Usin' your little chunk, press the pin back through the rotor that tiny 1/32" that you moved it in the first stage.
Watch the mark you made with the sharpie so you know when to stop. This will restore the pin in its original location within the rotor.

Do this NOW, do NOT wait until later.

Repeat for the other rotor.


Fingers are sore from typin', I'll do my best to press some rotors Monday and take pics of the process. It ain't magic, just common sense and a little bit've logic.

'bird

kenewagner - my mistake, many thanks for the compliment :)

Pictures would be awesome. Thanks for the sacrifice of your fingers on the typewriter
 
kenewagner said:
Pictures would be awesome. Thanks for the sacrifice of your fingers on the typewriter
Here we go...

Overall view of the rear rotor pins and the plate they're goin' into.
m90tech0286.jpg


Plate set up on the press, ready for the rotor pack.
m90tech0296.jpg


Standing the rotor pack on the plate and slippin' the pins into holes.
m90tech0306.jpg


Rotor pack in place on the plate, pins are down in their respective holes.
m90tech0316.jpg


I changed rotor packs for pics of the dirty work. Ram positioned over the pin to be pressed.
m90tech0326.jpg


Piece of 1/2" steel round bar used as a sacrificial chunk, placed on the pin to act as a buffer.
m90tech0336.jpg


Press until the initial "POP", only 1/32" or so of travel down through the rotor is needed.
m90tech0346.jpg


As mentioned above in my novel, set the rotor plate up with various pieces of stuff in strategic locations and press on the pin again. Rotor will slide down somewhat easily now and fall out the bottom.
m90tech0356.jpg


this help?

'bird
 
tbird88 said:
Here we go...

Overall view of the rear rotor pins and the plate they're goin' into.
m90tech0286.jpg


Plate set up on the press, ready for the rotor pack.
m90tech0296.jpg


Standing the rotor pack on the plate and slippin' the pins into holes.
m90tech0306.jpg


Rotor pack in place on the plate, pins are down in their respective holes.
m90tech0316.jpg


I changed rotor packs for pics of the dirty work. Ram positioned over the pin to be pressed.
m90tech0326.jpg


Piece of 1/2" steel round bar used as a sacrificial chunk, placed on the pin to act as a buffer.
m90tech0336.jpg


Press until the initial "POP", only 1/32" or so of travel down through the rotor is needed.
m90tech0346.jpg


As mentioned above in my novel, set the rotor plate up with various pieces of stuff in strategic locations and press on the pin again. Rotor will slide down somewhat easily now and fall out the bottom.
m90tech0356.jpg


this help?

'bird

I have all the equipment to do the job so it should be a cake walk. Only question I have is when installing bearings, is there a danger of damaging the bearing. I have pressed on bearings and diffrent kinds of bushings before, would freezing the rotor shafts in the freezer over night help when pressing in to the new bearings? Thanks for all your help bird. You and some of the other guys on this site always come through with helpful information. :D
 
kenewagner said:
I have all the equipment to do the job so it should be a cake walk. Only question I have is when installing bearings, is there a danger of damaging the bearing. I have pressed on bearings and diffrent kinds of bushings before, would freezing the rotor shafts in the freezer over night help when pressing in to the new bearings? Thanks for all your help bird. You and some of the other guys on this site always come through with helpful information. :D
In this case stand the rotor pins on a brass buffer plate, use pipe to press on the inner race of the bearing.

tip: don't forget to put the rotor seals in first LOL!

'bird
 
How much pressure required

Hi all, new guy here :)

Im wondering if tbird88 can help me out with a few questions on this. I have tried using a hydraulic press for the first step as shown in the great description from this thread, we ran it up to 3 tonnes pessure with no sign of anything moving at all. I wasn't brave enough to go higher with the pressure as im not sure how much maximum can be applied ?

If I do successfully remove them and replace the bearings and seals will I have a difficult job re-timing the rotors ?

Im in the u.k. and although I could ship the unit to magnusson or Wade at hsl I just dont think I could suffer the shipping, taxes, and duty charges which is why ive read this whole thread several times over the past 2 weeks.

Any advice would be great.

Mick
 
Hi all, new guy here :)

Im wondering if tbird88 can help me out with a few questions on this. I have tried using a hydraulic press for the first step as shown in the great description from this thread, we ran it up to 3 tonnes pessure with no sign of anything moving at all. I wasn't brave enough to go higher with the pressure as im not sure how much maximum can be applied ?

If I do successfully remove them and replace the bearings and seals will I have a difficult job re-timing the rotors ?

Im in the u.k. and although I could ship the unit to magnusson or Wade at hsl I just dont think I could suffer the shipping, taxes, and duty charges which is why ive read this whole thread several times over the past 2 weeks.

Any advice would be great.

Mick

This is a old thread you ressurected. I did install the new bearings. The problem I ran into is the timing of the rotors is very critical. In my case the blower ran for a while always making some noise. It ended up trashing the rotors. It is possible to time them I just didnt get it done, I had talked to Tbird88 who although posted some pictures of it how it could be done hadnt done one himself. He has since disappeared from here. I recommend paying to have it done, if it has problems at least you have warranty that you could possibily fall back on

Ken
 
I recently rebuilt a blower snout, which was not too hard. I haven't torn into the rotor pack, but I think you could time the rotors if you did.

Disclaimer: This is all untested ...

My idea would be to drill two holes in a plate that are precisely located to fit the rotor pins. (Alternatively, maybe you could use a cut-up blower case for this fixture.) Then you could use feeler gauge stock (those super-thin strips of metal) to shim between the rotors where they meet and make sure that the clearance is the same on both sides. Then you could lock the rotors in place (maybe using a dab of some glue that you could remove after you are done). Then line up the gears in a similar way (using shim stock again if necessary) and press them on.

One other word for the new fella: Rotor packs from recent GM cars equipped with M90 superchargers are interchangeable with these rotor packs. They have two key benefits: first, they are much newer; and second, they are coated with an epoxy coating which increases efficiency (an improved version of the coating on the 1994-95 Thunderbird SC blowers). All you have to do is drill and relocate some locating pins. So, this could be a good "Plan B" for you, if not "Plan A".
 
Or send it to the High speed lab, Wade is the only one I know that has a Jigg to get the job done. Not even MP gets involved in this repair. Eaton might have one too but who want to deal with the manufacturer/. :rolleyes:
 
Another option is to send your blower to Magnusen to have brand new rotors installed. They'll have a nice shiney new coating on them and everything.


Of course then there is the tax thingy and all that. Another problem you run into when replacing the bearings is that when they come out they break away a swedged part of the bearing plate so when you install the new bearings you have to devise a retaining method for them.
 
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I thought the marker was for timing the rotors. Make a mark on the rear of the rotors and line them up. Only do it on one rotor with one style mark. I.E. Use lines on one rotor. Then, go to the next rotor and use "A" with a line. This is how I line timing chains up for the 4.6s and it works wonders.

Chris
 
Third option

The third, and most cost effective option, would be just to nab a complete used blower from the for sale forums here or ebay. If you car is an pre-94, you should be able to score a nice 94/95 blower for $350 or less, or an early blower for $250 or less. If you get a 94/95 make sure that you also get a 94/95 intake plenum too, and you'll add some HP at the same time. You'll pay $400+ for a GM rotor pack, and probably much more than that to have your pack professionally rebuilt. You'll be taking your chances with a used blower, just like buying a part from a scrapyard. But chances are that a used blower that looks OK will only need the snout rebuilt at worst, which is relatively inexpensive. The rotor pack and rear bearings should be good for 200k + miles if it hasn't been abused (like mine :) )
My $.02

Daspanka
 
I have tackled a lot of diffcult projects since I bought my SC, from M112s & whipple blowers to most everything mechanical on the car. The one thing I wouldnt do again is tear the rotor pack apart and reassemble it with the rotors timed. I played with it several times to get it where I thought it should be. The tolorances are very close and if its not perfect it does what the pictures show. I beleive there are only a couple of members here who have tried it if that and even if they lucked out and got it right doesnt mean the next guy will be lucky. Even a few thousands off will tear the coating off at minimum. And as dave said pressing the shafts out will destroy the roll over that holds the bearing in place. Another problem that needs to be addressed. Spend the money to do it right or buy something diffrent. Also my case is trashed and if you look closely to the pictures you will see scoring and flat spots on the rotors. Only good thing about it was it allowed me to move up to a bigger blower

Ken
 

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