M90 help...

I'm going to assume...

You already have the unit apart aka the rotor pack is out and you just have an oily rotor housing. If not, you need to diassemble it first. I put mine on the driveway, bearing end down on 3 blocks of wood. One centered between the bearings and one on each side of them. I used an old 12" 3/8" drive extension with a socketand carefully pounded them out. I can't remember what size socket, but pick one slightly smaller than the bearing so as to not damage the bore.

Some people drive them through from the back into the case to remove, but I don't think it matters. Do what you feel comfortable with.
 
You already have the unit apart aka the rotor pack is out and you just have an oily rotor housing. If not, you need to diassemble it first. I put mine on the driveway, bearing end down on 3 blocks of wood. One centered between the bearings and one on each side of them. I used an old 12" 3/8" drive extension with a socketand carefully pounded them out. I can't remember what size socket, but pick one slightly smaller than the bearing so as to not damage the bore.

Some people drive them through from the back into the case to remove, but I don't think it matters. Do what you feel comfortable with.


and did you hammer them back in the same way or you how ever it worked out..
 
I would burrah a press after freezing the bearings and leaving the case in the sun. That would get them started and go from there.

Chris
 
So how about putting in new ones? Let sit in the sun and freeze the needle bearings? Someone told to put the casing in the kitchen oven at 250 degrees and they will slide in that way? Any help here?
 
To install...

You can install them the same way as removal. I recommend installing them from the outside. You can get them pressed in if you like, or you can do it yourself the same way as removal, with a hammer and appropriate size socket. They will take some effort to install, but I see no purpose in the whole freezing/baking scenario. It is absolutely not necessary and I don't even believe it makes it easier. I found they are properly installed when the back of the bearing is just below the surface of the case, but you can go as far as making the bearing front flush with the inside of the case.
 
You can install them the same way as removal. I recommend installing them from the outside. You can get them pressed in if you like, or you can do it yourself the same way as removal, with a hammer and appropriate size socket. They will take some effort to install, but I see no purpose in the whole freezing/baking scenario. It is absolutely not necessary and I don't even believe it makes it easier. I found they are properly installed when the back of the bearing is just below the surface of the case, but you can go as far as making the bearing front flush with the inside of the case.

So your saying then that metal and especially aluminum doesn't expand/contract with heat and cold?

Hammering with a socket a press fit item into an aluminum casing is just asking for nothing but trouble. Are you absolutely 100% sure your hammering those things in straight into the case. Aluminum has the nasty tendency of allowing itself to be gouged instead of expanding to an item that is stronger like steel, hence the reason for heating cooling in the first place, even with a press.

For something that spins at such high RPM's, I'd sure want it done right the first time.

To each there own I guess.
 
I'm agree with Frit on this one......

We shrink fit lots of items into all kinds of bores.......

Liquid nitrogen works wonders.....:p
 
I do the same as deepblueSC when I remove the bearings. But I do freeze them for a couple hours and the slide about 1/4 way in from the backside. I then take a hammer and tap them down until flush. Done this to quite a few chargers and no problems.
 
did my needle bearings without freezing or heating worked just fine. have many miles on that m90 too. i used a machined peice of teflon to hammer them in and out instead of a socket.
 
I just asked my wife and she said best is at 350, and will take a least a few hours... by using a thermometer, when the core temp gets to........... oh wait a minute, your talking about the blower :eek:
 
OK thanks guys...NEXT QUESTION

Next question...

Do I use gasket maker to put IN between the case, rotor pack and snout?
 
I think you need 6 to 8 ounces. The GM supercharger oil comes in small 4oz bottles, I think. I know I needed more than one to fill up my blower.
 
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