RedLS1GTO

I know I know... ANOTHER bearing thread. I have searched for quite a while and have yet to find an actual answer. I'm in the market for some new wheel bearings for the C4 track car. I have found OEM and Timkin which most people seem to think won't last worth a crap. Then there are the rebuildable ones being sold on here, but honestly I'm not sure I want to spend $$$$ on a product from an individual as opposed to a company. Supposedly SKF makes some, but after a lot of searching I have come up empty. WHERE oh WHERE can I buy them?? A decent price is always a plus of course.

Is there another option that I am missing along the way?? Thanks as always.

TJM

HardbarUSA.com But you REALLY have to want to spend money.

Check the Forum for threads called "Rebuild-able C4 Wheel Bearings".

Very interesting. There is fellow that has rebuild-able ones there [ ? SKF]. But the price only gets higher!!!


I think I am going to pursue a re-build able BALL Bearings route.

I am pulling a hub this weekend and tearing it up.

I think replacing set of ball bearings every couple of events is better than going the Big Buck route.

In fact with a purchase of some OEM versions from ZIP or a similar Forum seller, I will have a spare set of hubs?

I am not sold on the tapered or roller bearing route?

I don't want to slam any one's product or background, but the General didn't go from Tapered bearings to Ball bearings on C4 for a "Cost savings" measure.

There is a reason.


TJM

ghoffman

There is no SKF bearing option for C4's. The SKF is the best out there, but is is C5/C6 only. The SKF are much stiffer ball bearings with thicker flanges (many folks on this forum have broken the OE flange). GM went with the angular contact ball bearings for rolling resistance reasons. Almost all race cars (T/A, NASCAR, etc) use tapered roller bearings.

TJM

Is it possible to rebuild the Ball bearing units?

Or an I wasting my time??

TJM

ghoffman

No, the only one I am aware of is that one guy.

TJM

This is making my ears bleed!!!


I have spoken with him, sounds great if I were a GT2 guy, but the cost is very high. Real HIGH!!!

The question nagging me is the practicality of replacing the Ball Bearing races ? With Ball Bearing Races?


TJM

MJM Racing LLC

The races in the stock units are machined integral with the housing and rotating shaft. They can not be replaced. From my experience dissassembling them, you can not do it in such a way that they can be reassembled the same way they came apart. That came out awkwardly. You have to cut the ABS reluctor ring boss pressed on the shaft to take them apart, so unless you re-weld it, it doesn't go back together right. Plus, most of the wear appears to be on the races, not the *****, so replacing the ball bearings would do little good.

TJM

Thanks for playing, Mike.

I am at a disadvantage, not having a drawing or part in my hand.

So, machining the race surfaces is the actual repair procedure, if that is what we can call it for the sake of the conversation.

I assume they [ bearings ] run square to the finished surfaces? No races cut into either bearing surface?

Is the wear on the spindle race surface, or the flange race , or both the same? Front to rear as well? I would guess the flange side to be the weak sister?

Hmm? Either way, no simple fix. We could be cutting metal in both directions? There seems to be enough Hip to do it, but sealing would be problematical? unless you xerxed the back of the knuckle?

Incrementing sizes will be next to impossible? I can't imagine a source of readily available "next size " up ball bearings?


Geez,... I'm making your argument for you?

TJM

MJM Racing LLC

I think the one part you are missing is that there is no mechanism in the stock assembly to adjust the end play. The bearings are retained by two semicircular clips riding in a groove on the shaft (think valve keepers without the taper). The ABS reluctor ring boss presses down over the "keepers" so they don't fly out. So if you machined anything out there would be no way to get them tight again.

In mine, I machine out the ball bearing races from the housing and press in tapered bearing races. I use a new spindle shaft of my design with threads on the end and a spindle nut so they can be adjusted.

RedLS1GTO

So.... what you are saying is that I am pretty much up that famous creek and the only way out is to build a paddle out of dollar bills? The guy selling the re-buildable ones are... about $700 a pop if I remember right. No warranty, and they still need to be rebuilt every so often so if he stops making parts you're pretty much up that creek again.

How ridiculous is it that a performance car with a production run of over a decade doesn't have supporting parts to keep it on the track?

MJM Racing LLC

Not quite up the creek should I ever stop making them. The bearings, races and seals are commonly available parts. There is really no reason you have to buy them from me other than convenience if you don't want to source them yourself. I will gladly provide the part numbers to anyone that buys them. Unless you can buy bearings wholesale, $75 a side is about what you'll pay a bearing house for the parts.

The current price is $750 each.

MJM Racing LLC

I know these things are expensive and I really wish I could make them cheaper. The only way that can be done is with a large order. So if you guys think a GP could be filled, I'm game. If we can get 10-19 pair, I can drop the price to $700 each. At 20+ pair I can drop the price to $650 each. I know that's still alot, but it's better. This reflects directly passing on the reduction in cost I get from ordering quantities of the new spindles. I can't afford to make and stock this many, so normally they are made to order, one pair at a time.

RedLS1GTO

First off, I didn't realize that you (MJM) were the one making the rebuildable ones. Thanks for the replies. Is there anybody out there yet that has used them for an extended period of time on a road course??

I think I'm more confused than ever (and that's a lot). Is there any way short of $1500 a pair to get a tapered bearing on the front of a C4? Are any of the F-body bearings that will work tapered? Are there any ball bearing style that will actually last??

This is really getting annoying. On a side note. When exactly do the bearings NEED to be replaced on a track car??? Street car is easy. When it gets annoying, change it I have a little bit of play in both fronts. No noise, no grinding...

Thanks as always for helping with my continued education.

BrianCunningham

pay now or pay later

the stockers won't cut it

nothing else will fit the stock housing.

larryfs

I got SKF bearings on my C4, front & rear.
maybe I'll go into business.......................

For the rears, you go into NAPA, and order NAPA bearings, Made by SFK in a NAPA box, with a lifetime warrenty.

For the fronts, you need to be creative. Order 1993 F-body front bearings directly from SFK. I ordered them as a distributor.
I drilled out the threads, and made the hole the correct C4 size hole.

The SFK's take a beating.
I wouldn't waste my money on anything else.

and believe me, I tried EVERY bearing out there. Auto zone, pepboys, AC-delco. I got maybe 2 laps out of them. I could do a bearing job in 10 minutes. It was ridiculous.

I got 2 seasons plus out of SKF, and they are still good.

If you do some google work, you'll find them.

In fact on a rear SKF, after 5000 track miles; the grease seal failed, and oozed out grease. The bearing got noisy, (otherwise I wouldn't have known) but the bearing was still TIGHT !!! Not one drop of play. NAPA exchanged it no questions asked.

I never ruined a front SKF. They seem like the solution.

RedLS1GTO

EDIT: Is this the mythical SKF hub for a C4?? There are a few places out there that seem a lot cheaper but Amazon has a good picture. http://www.amazon.com/SKF-BR930186-H...1170852&sr=8-1

EDIT again: Correct me if I'm wrong... use NAPA on the rear, and the 93 F-body on the front for wheel bearing perfection. Is there any way to make sure that the rears are SKF from NAPA? A stamp or other marking?

TJM

After finding actual bearing drawings, I see the physical problem.

Know the hard part... inventory 24 hubs for replacement @ $60 a pop. or buy a racing solution and pay $75 a pop to replace them.

I guess it is a "frequency issue" that will be the determining factor. Like Cunnigham said " Pay me now or pay me later" ?

Thanks for the input Mike and Good Luck, sounds like you might have a better mousetrap.

TJM

TJM

Question? Are they rebuild-able Sounds like a "no".

Typical disposable unit. After all SKS invented these things.

Are they Ball Bearings? Sounds like a Yes?

If yes and if they cost around $400.00 a pop I can see why they are expected to last!!

"Long is relative though? "

But the rebuild-able ones might still be a good idea if you really flog your car.

I am applying this to a "track" only car that will see a couple 1,000 yearly track miles with three different idiots driving [ me being one ].

The budget is steep, but bearings never occupied a four figure line item!!!!

Uggg.... Of all the things I didn't think was going to be an issue, this has turned into the prime candidate.

TJM

RedLS1GTO

We have a winner with that comment. I know things will wear out and things will break but I never put wheel bearings so high on the list. At these prices they are right up there with tires and brakes!

MJM Racing LLC

I have disassembled SKF as well and Timken, AC Delco, Federal Mogal and a few I could not define. All were built exaclty the same way. The only way the SKF units could last longer is if they have better materials (very possible) or better heat treating (also very possible). At a sale price of $450 for a throw away unit, I'm not sure it's a better option than the rebuildable ones. Everyone will have to decide that for themselves.

There is no magic in '93 F-body hubs. The same hubs fits '93 to '02 F-body. I originally built the rebuildable version for F-bodies because they go through hubs just as fast or faster then 'vettes (more weight). An no, no F-body hub had tapered bearings.

I actually don't know how my existing customers are using their hubs. Other than a couple questions about preload and how often to grease, I haven't heard much from them. Generally, no news is good news. I certainly hope they would contact me if they had any issues. So if anyone has lots of track miles on them, I don't know.

One of the early prototype sets was tested on a road course. It had no issues after about 150 miles of RR use. The same hub had several AX events on it before and after. One of those hubs did eventually fail due to a materials problem. This is what prompted the use of new 4340 forged and hardened spindles. None of the new spindles has ever failed. I mention this because the bearings lived through all of this with no visible signs a wear and were only regreased once. The same bearings were used on the new spindle and are still in use.

I've had a set of the latest version on my Camaro for over a year now and they have over a dozen AX events and thousands of street miles on them. The bearings in the date back to earlier versions and have even more events and miles on them.

I guess the point is, as long as the bearings don't dry out they will last a long time. How long, I haven't been able to kill a set yet so I don't know.