I'm currently rebuilding my M62 supercharger which is going onto my V6 MR2. I bought a rebuild kit from the States and am going through the various youtube videos.

However, on taking the rotor pack out this evening there seems to be damage to the black coarting on the rotors at one end. I believe this is caused by excessive play in the bearings causing the rotors to come into contact with one another, which is the reason I'm rebuilding anyway.

Now, I'm guessing this isn't a good thing, but is it sufficiently bad that I need to do something about it? If so, what do I do? Can the rotors be re-coated or is it replacement time?


M62 rotor pack

Also, the video guide I've been watching states to use 'blue' grease, which I've never heard of. I'm guessing it might be an American term. Any clues as to what it it's called over here?

Thanks, Chris

Chris, Not sure about the coating, I have heard some just remove it all as it flakes off rather than wears. May be it can be recoated.I believe the grease is fully synthetic high temp silicone grease. I bought some from the states, it is not blue but meets the spec. I also have a set of rear caged needle roller bearings and a set of front rotor bearings and seals, (the ones behind the two drive gears) You can have the lot for half what i paid which will be about £35. I was going to rebuild the Eaton charger I have but not going to now.

Steve.

[Edited on 16/4/12 by stevec]

We used to use blue grease in work, it was skf bearing grease

It's really thick and stains every bloody thing

Hth
Stott

Chris, a post on guy croft's forum is worth a try. Normally Guy will answer posts himself but there are quite a few s/c fans participating.
He's one of the best automotive engine engineers I've come across so you can take his word as gospel!
He offers a coating service on Volumex s/c so I can't imagine an Eaton will be a problem.
HTH.
Cheers, Pewe10

Just A N Other thought - IIRC the reason they moved to teflon coating on the Mini s/c was to do with the fuel mixture "adhering" to the blades when they were un-coated. I take that coating gives a significant advantage as car manufacturers aren't known for up-grading an item for no good reason - especially when it involves a cost increase! .

[Edited on 16/4/12 by pewe]

quote:

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Originally posted by stevec
Chris, Not sure about the coating, I have heard some just remove it all as it flakes off rather than wears. May be it can be recoated.I believe the grease is fully synthetic high temp silicone grease. I bought some from the states, it is not blue but meets the spec. I also have a set of rear caged needle roller bearings and a set of front rotor bearings and seals, (the ones behind the two drive gears) You can have the lot for half what i paid which will be about £35. I was going to rebuild the Eaton charger I have but not going to now.

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K323 Premium Blue Grease (PBG)

Premium Blue lithium / calcium base grease is an extremely sophisticated lithium / calcium base grease which incorporates ...


http://www.morrislubricantsonline.co.uk/scripts/prodView.asp?idproduct=84
data sheet:
http://www.morrislubricants.co.uk/Downloads/TDS%20K323.pdf

I have a similar charger for my MX5 engine.

I am reliably informed that you cannot change the needle bearings without risking damaging the casing. When they are pressed in they deform the case. I have however seen on youtube someone remove them with a slide hammer.

The coating is the same as on the MINI and is there to increase tolerence with the blades. Is does tend to wear off. The older charger didn't have it so it's not that important.

High temp grease is ok.

Thanks Roger. The kit I've got has the needle bearings in (I think - I've not opened all the boxes yet!) so someone must think they're changeable. However, if they're pressed in, I've no idea how to get them out as there is no access to the back of them in my casing!

I should point out that it's a TRD casing designed for the US-market Toyota Camry which runs the same V6 as I have in the MR2. It's basically an M62 rotor pack fitted into a casing suitable for direct mounting onto the engine.

Chris

Thats exactly what I thought. I bought some rebuild parts for mine from a US supplier. Nose bearing coupler etc. The supplier assured me that they replace the needle bearings when they rebuild them using a slide hammer then press them back in. On MX5 Nutz the resident expert assures me there is a real danger of damaging the case if I try.

I am really tempted to give it a go though. My charger isn't too old and the general consensus is that the nose bearing is the stressed one and the plastic coupler wears. Change those and regrease the needle bearings and refill the oil and that should do it.

Chris you should be able to remove the bearing using the 'old school method' hydraulic lock. same as removing a clutch shaft bearing from a flywheel. Get a shaft that fits into the bearing easily (may have to turn something up) then fill the bearing hole with grease, insert made up shaft and hit with hammer, the hydraulic affect is that the bearing will drift up and out. Warning ensure the case is supported on the outside as the effect is the same as driving a drft directly through, and place a rag around the shaft/drft as grease will try to escape at great velocity.

David

Thanks everyone. Perhaps I'll leave the needle bearings alone then! I assume we're talking about the same bit - the ones at the opposite end of the rotors to the snout?

The guy that sold it to me told me that the 'charger had bearing noise. He had another, so he just swapped over. When I took the snout apart last night there wasn't a drop of oil in it, which I guess will be 50% of the problem. The drive gears don't look worn though so hopefully I've got away with it.

Which brings me to another question... how much oil do I put back in it? Is it critical or can just pour 'roughly' the right amount in? I've seen syringe kits on eBay, hence asking how sensitive they are to too much/too little.

Chris

Oil is very important. 100-110 ml. Don't overfill!

I believe most of the noise comes from the nose bearing and the coupler and in a lot of cases lack of oil. I am told the needle bearings wear less.

As you can see I am no expert but have taken a lot of advice and read a lot.

My plan is to re grease the needle bearing, change the plastic coupler and oil. Mine isn't very noisey and I hope that will be enough.

I would expect if the needle bearings are worn then the blades and casing would show signs of wear. The tolerance is tight for obvious reasons so it wouldn't take much for them to touch.

quote:

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Originally posted by rdodger
I would expect if the needle bearings are worn then the blades and casing would show signs of wear. The tolerance is tight for obvious reasons so it wouldn't take much for them to touch.

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Do the edges/ casing show any signs of wear or is it just the coating coming off?

It is not uncommon for the coating to come off on an otherwise healthy charger.

Not sure... I'd have to go and have a closer look!

Chris

I replaced the nose bearings, oil and coupler only and it went from very rattley to nice and quiet.
If stuck for bearings the guys at Bearing Boys were more than helpful and cheap.
I have instructions from the US about overhauling the items above if you want, Chris - drop me your email and I'll send a copy.
Also there's debate on MX5Nutz and/or MX5 O/C (can't remember which) about tensioner pulleys.
Mine on the 5 were diddy 1" jobs and sh*gged to the extent they were tapered(!) - naively I thought I could just turn them around and it promptly shredded the belt x 2.
Moss Europe supply replacement pulleys but they are eye wateringly expensive for what they are.
Next time I'll change to the set-up I've used on the Volumex which is a Passat adjustable cambelt idler pulley onto a home fabricated plate attached to the blower casing as per Guy Croft's instructions.
More details if you require them.
Cheers, Pewe10

Thanks Pewe. Picked up a hydraulic press today so I can start disassembling in anger.

My email address is on the contact page for this site..... http://locostbuilders.co.uk/contact.php

Cheers, Chris

By the way, I tried signing up for that supercharger forum, but a week later I've still not been approved by the admin.

Chris