Need advice on replacing balls from ball drive (SN89)...

[Michael]

Hi guys,

I've read through all the archive documents, and done a ton of searches on the internet (Google) and I've found alot of good information with respect to the ball-drive setup in these SN series chargers.

I am going to order a new set of balls for the ball drive of my SN89, and from what I know already, I need to get five, 1 1/16" dia., grade 25 (minimum) balls. But before ordering I wanted to run a couple of minor things past everone here to see what you all thought.

1. Rather than ordering grade 25 balls, I am considering grade 3. From what I have seen, the lower the grade number, the more precise (ie. smoother) the surface finish. I'm certain that grade 3 balls will be more expensive, but the cost shouldn't be an issue. I just want to make sure that this is an OK idea before going ahead with it.

2. What material should I get the balls in? The guy I bought the charger from suggested brass balls, because if/when they deteriorate, the material clumps together rather than chipping and falling appart like harder metals. Makes sense, but I'm not sure they would be able to handle the heat/pressure. I'm pretty sure the balls in these superchargers are stainless steel, so I'd rather stick with the original design. But should I order up "regular" stainless steel, or should I get hardened stainless steel? I've read arguments on this site for using balls that are TOO hard, and the potential damage they could cause to ball-locator and input shaft if they fail.

Thanks very much in advance guys! :)

[F=MA]

It's always better to have brass balls when you drive a V8 car with a supercharger...:blob:

However, in this case, the balls are a precisely calculated wear item. Use stock ones and don't experiment here. Brass would be ground to bits in no time by the 100,000 psi pressures in the ball drive.

F=MA

[Michael]

It's always better to have brass balls when you drive a V8 car with a supercharger...:blob:

This is something I'm sure I will soon discover for myself! :laugh: :laugh: :laugh:

However, in this case, the balls are a precisely calculated wear item. Use stock ones and don't experiment here. Brass would be ground to bits in no time by the 100,000 psi pressures in the ball drive.

F=MA

I agree with respect to the use of brass. The reasoning made sense when the guy first mentioned it, but now that I've done some research and have a better idea of the pressures and temperatures the drive-balls are exposed to during regular use (let alone hard use) I don't think that brass would be such a good idea.

I have no problem using stock replacement balls, and I know I could easily order them up from Paradise Wheels, but I'd rather try to get a set locally. That way, if I need to rebuild the unit again in the future (or if I decide to get another unit that needs rebuilding) then I'll have a source for parts that's geographically closer to me than California (I'm in Ontario, Canada).

But even if I go with the stock grade 25 balls, I still need to know the material and hardness. Any ideas?

[5.0 Chero]

Their are Orignal type rebulid kits on ebay http://cgi.ebay.com/ebaymotors/Paxto...QQcmdZViewItem

The second one has ended but he list them all the time.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=7993943666

[Michael]

Their are Orignal type rebulid kits on ebay http://cgi.ebay.com/ebaymotors/Paxto...QQcmdZViewItem

The second one has ended but he list them all the time.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=7993943666

Yeah, I've seen those kits. They are listed by Craig at Paradise Wheels Inc, out of San Marcos, California.

I don't mind getting the kit he has on eBay (I could always just call him too), but like I said, I'd rather try and get the stuff locally. Besides, alot of the replacement pieces for these SN series chargers (other than either the front or rear seal, I don't remember) is available as over-the-counter replacement pieces, so finding them locally would eliminate the shipping costs and the waiting time. And it would make it easier if I need more parts later on too.

But thanks for the advice though. Cheers.