Re-Furbishing 3 Piece Racing Wheels

[DaveW]

I wonder, does the point on the track where the failure occured offer a clue?

For instance, if the cornering stresses were the cause, would the wheel most likely break in a corner? Or, if the failure was due to braking forces, wouldn't the wheel have failed under braking?

I don't think so. The wheel ultimately failed from the cracks that had been propagating for a relatively long time. So the initial cause of the cracks is the important factor. It could have failed anywhere that it was under load.

[disquek]

Hi,

I'm a GTL guy who reads ApexSpeed for the great info.

One thing you guys might consider is in one of Carrol Smith's books (not sure which one), he recommends painting wheels with lacquer only since it will show cracks where epoxy or enamel will hide the crack. Certainly it will not hold up as well, but he also recommends re-checking and re-painting them annually.

Just a thought. I have 20 Panasports that I need to refinish too.

EDIT. I found it:
http://books.google.com/books?id=5a8...page&q&f=false

-Kyle

[J Leonard]

My wife has forbidden me to race on compomotives. Broke the centers out of two of them. The second one broke after pro NDT at a night race with lots of sparks. Non ground affects super vee based sports racer. Wheels were unmodified and may have been just to weak for the car.

[Swift17]

What would be the torque specification to be used during wheel assembly for this type of wheel - and I can I ass u me:

A. "crossways" tightening sequence for the 18 bolts,
B. "stepped" torque amounts (i.e 10 - 20 to final 30 lbs) appropriate ?

EJ

[DaveW]

What would be the torque specification to be used during wheel assembly for this type of wheel - and I can I ass u me:

A. "crossways" tightening sequence for the 18 bolts,
B. "stepped" torque amounts (i.e 10 - 20 to final 30 lbs) appropriate ?

EJ

30-ft-lb is too high unless you have 3/8" bolts...

What size bolts? What thread? What locknuts? It makes a difference...

Assuming 1/4-28 threads and Nyloc nuts, I'd say ~10 ft-lb. On mine, with 1/4-20 coarse threads (flange-button-head Allen bolts from McM) and grade C all-metal locknuts, I calculated that I had to use 14 ft-lb to achieve the proper clamping force.

I snugged mine with an air ratchet, and then final torqued them in sequence. If you are really compulsive, then you can do your A and/or B. However, there is nothing to flex and compromise the torquing, since there is nothing between the bolt-head and the nut to flex significantly. If you want to be really sure, just go around twice.

[RussMcB]

Was spray-on paint stripping mentioned earlier? I'm too lazy to go back and read through the posts.

I have some Compomotives from a car I just got. They had painted centers, didn't look great and needed general cleaning up. I decided to redo them before mouting my rain tires on them.

I inquired around about media blasting but didn't have much luck. A few people suggested spray-on paint stripper. I tried it and it worked pretty well. Most of the old (blue) paint came off very easily.

I ordered 4mm o-ring material from McMaster Carr and it arrived very quickly - about the same time I realized that each wheel uses two o-rings, not one. Doh!

[DaveW]

...
I ordered 4mm o-ring material from McMaster Carr and it arrived very quickly - about the same time I realized that each wheel uses two o-rings, not one. Doh!

Russ, I would not use o-rings in any case. They always start leaking in a year or 2 after they take a set. I've had MUCH better luck with the Dow 832 sealant without any o-rings.

[Charles Warner]

I inquired around about media blasting but didn't have much luck.

Russ,

Buy yourself a small/medium blast cabinet and do all these things yourself. It's worth it. Tip Tools.

[Hawke]

I did this with a small blast cabnet with plastic media, and it worked great. Firstly used a non caustic stripper to get most of the paint off the centres and then blasted. Painted with a two pack gold. So far so good.

Torqued the 1/4" aircraft bolts and jet nuts to 12 ft lb.

Had some difficulty in getting the bead of sealent to seal and bond to the metal. In the end, I had to blast the inside of the rim halfs to remove the stuff that preventing the bonding.

[Swift17]

Dave - all hardware on the originals had allen cap screws and metal locking nut with washers on each side - Love the flanged concept BUT I can't seen to find on McM -- I DID find metric ones - Am I looking in the wrong space/page ?

EJ


-

[DaveW]

McMaster-Carr

Search for "button head flange cap screws." Material steel, black oxide finish. The range of lengths is limited, though, to 1". And they will rust if not maintained. They have them in SS, but, IIRC, they were not hard enough.

The nuts I used are grade c lock nuts (distorted thread hex lock nuts). They are available with or without flange.

[RussMcB]

Many months later, I finally assembled a full set of four for FF. Many thanks for the posters who offered good suggestions in this thread and others.

[Joefisherff]

Great work Russ, they look great!

[Swift17]

I agree ............. see my labors on twelve just finished this past weekend -- and stilll looking for some "215s" centers if available.

[Joefisherff]

Nice work EJ they look great too.

[jgrooms]

I had a few sets I needed to strip. I bought a plastic feed tray at Farm and Fleet, Round and deep enough to fit a wheel center. Then I soaked them in acetone for a few days each. I covered the pan so the acetone didn't evaporate or cause my brain to rot further. Once I soaked them for a few days the paint came right off. Maybe a slight scrub with a nylon brush. If your wheels have the original paint it will come off easily.

After you store the acetone in the original can for a few days most of the paint sediment sinks to the bottom and you can use it for the next wheel.

No abrasives, no hassle and acetone soaked metal is ready to paint.

BJ told me laquer paint but I just used krylon spray cans. A thin coat to avoid obscuring cracks.

A real headache to put them together without leaks. BJ also told me a thin coat of 832 on the mating surfaces. I have had pretty good luck doing it that way. Yes it makes a mess of the bolts but once the silicone squishes out to the center section you can smooth it with your finger and form a good seal.

BJ also told me 12 Lb/Ft for my 1/4 inch bolts.

Finally, he told me that the 202's and most of the old wheels had more than enough hardware. Apparently similar wheels have been made with 6 bolts and worked fine so the bolts and number of fasteners are not an area for concern in terms if a hardware failure.

John

[swiftdrivr]

Does anyone know of a media other than Soda that can be Safely used to clean wheel centers for NDT? I was considering buying one of the $200 blast cabinets from harbor Freight, and doing it myself, but it appears you need a Soda conversion kit to blast with Soda, and this is only offered with the more expensive blast cabinets. ---Jim

[Charles Warner]

walnut shells?

[swiftdrivr]

For a detailed, sometimes opinionated, sometimes self agrandizing, sometimes informative forum [No, not the Kent vs Fit thread] about soda blasting, see below. Sounds like plastic bead is an equivalent, non volatile, not a threat to lungs, but more expensive media C/W soda.----Jim

http://www.hotrodders.com/forum/soda...-128088-5.html

[swiftdrivr]

[swiftdrivr]

My Hyashi wheels [ also shown in the post above ] are giving me problems. I removed the nuts, but the bolds won't come out, or even turn. I am bending a 5 mm metric allen wrench, and they won't break loose. I 'gently' tried hammer therapy without effect. The nuts look like they have loctite or some other sealant on them. I suspect I need to heat the wheels to 500 degrees, as loctite suggest to break loose loctite red. As my wife isn't going to loan me the oven, the only way I have to accomplish this is a propane torch. Does anyone know if this will harm the wheel or make it unsafe? Any better ideas?---Jim

[Charles Warner]

First determine whether they are ally or mag. Makes a big difference.

[DaveW]

My Hyashi wheels [ also shown in the post above ] are giving me problems. I removed the nuts, but the bolds won't come out, or even turn. I am bending a 5 mm metric allen wrench, and they won't break loose. I 'gently' tried hammer therapy without effect. The nuts look like they have loctite or some other sealant on them. I suspect I need to heat the wheels to 500 degrees, as loctite suggest to break loose loctite red. As my wife isn't going to loan me the oven, the only way I have to accomplish this is a propane torch. Does anyone know if this will harm the wheel or make it unsafe? Any better ideas?---Jim

500 degrees sounds a bit excessive, at least initially. Even 200-250 degrees F will soften the Loctite a lot. A heat gun can locally heat the bolt enough to soften Loctite. Also, a good penetrating oil will help to loosen the bolts and maybe make them possible to be removed. Have you tried an impact driver (the ones that twist the bolt when you hit the driver on the end with a hammer)?

[swiftdrivr]

WD-40, heat, impact wrenches. Nothing has done anything but strip the allen heads. Next idea is NDT on the wheel as it is assembled. Not ideal, but probably helpful. Any other ideas / thoughts?---Jim

[DaveW]

Have you tried to hit the thread end of the bolts with a hammer, or hammer with pin punch? Heat to expand the Aluminum/Mag in combination with hitting the thread ends could work. It is not likely they are threaded into the wheel material. You may have to destroy the bolts to get them out - they are likely corroded in place from years of use.

[swiftdrivr]

I used an old 1/2 inch extension and a sledge hammer, but I imagine I can be a bit more aggressive than I have been. I considered drilling them out, but there are a bunch of them [48 I think.] I originally thought it was loctite, but the nuts came off easy enough, so I guess you are right. Ccorrosion is probably the culprit. pretty impressive corrosion, though. I think I could race the wheel without the nuts!I'll give it another shot. Thanks for the suggestions.---Jim

[Dick R.]

Can you mount a tire (maybe a relatively wide street tire that will "want to spread")and CAREFULLY apply air pressure to help spread the inner rim away from the center and outer rim? I assume for your wheels that both rims are on the inside of the center. Mine straddle the center. If you go the bigger hammer approach I would sure be careful to support the center around the bolt being hammered.

Dick

[swiftdrivr]

Hyashi welded the wheel halves together [And the bolts in place, apparently] I've beat on it as much as I dare. If I break a wheel, I have no spares. I'm going to strip the paint with Jabsco, and see if they can xray and dye pen the center in-place. Thanks for the ideas.---Jim

[DaveW]

Hyashi welded the wheel halves together [And the bolts in place, apparently] I've beat on it as much as I dare. If I break a wheel, I have no spares. I'm going to strip the paint with Jabsco, and see if they can xray and dye pen the center in-place. Thanks for the ideas.---Jim

IMO, it's not possible that the steel bolts could be welded to the aluminum/mag rims/centers. And, it's unlikely that anything but corrosion on/around the bolts is holding the rims to the centers, especially if the rim halves are welded to each other. There may be some differential thermal expansion adding to the difficulty, especially if the rim halves were welded together in place. You may have to drill out the bolts. If this is necessary, you might be able to make a drill-guide to screw onto the threads so that the drill-bit is centered on the bolts while you drill them out.

That must be some severe corrosion! If it were me, I would not want to run these until they can be disassembled for inspection and, probably, bolt/nut replacement.

I just had another thought - how about a press to push on the thread-ends of the bolts while supporting the opposite side with a socket or something that supports the wheel while clearing the bolt heads?

Yet another thought - from hard hex stock, make a blind-end nut that contacts the thread ends before tightening on the rim half. Then you can try to start screwing out the bolts by turning these blind nuts.

[swiftdrivr]

Dave, I was just kidding about the welding. I like the blind nut idea, though. Come to think of it, it kind of sounds like me.
Thanks,
Jim.

[DaveW]

HAHA... blind nut - in some cases I've fitted that description...

I thought of a better way to make this:

1. Get some pre-hardened hex steel (4140, 4340, etc.) and cut off a section ~1" long
2. Drill the tap size drill all the way through
3. Tap the hole all the way through to the thread size of the stuck bolts
4. Get a hard (GR8) bolt and a hardened nut, same thread
5. Thread the hex onto one of the stuck bolts, but not all the way to the wheel
6. Thread the hardened nut (to be used as a jam nut) onto the GR8 bolt
7. Thread this into the hex until it bottoms on the stuck bolt
8. Lock the jam nut firmly
9. Turn the hex (or maybe both the hex and the hardened bolt at the same time) until something happens.

This is easier to make than a bottomed out thread, and less likely to strip or jam together.

[RussMcB]

Maybe this was already tried, but what happens when you put the nut back on the stuck bolt (screwed on enough to be flush with the end of the threads), then whack the nu? And/Or, using a press in a similar fashion (after whacking and penetrating oil to loosen)?

[DaveW]

Maybe this was already tried, but what happens when you put the nut back on the stuck bolt (screwed on enough to be flush with the end of the threads), then whack the nu? And/Or, using a press in a similar fashion (after whacking and penetrating oil to loosen)?

Maybe a combination of your and my ideas would work... Hit or press on the end of the ass'y I described - this would be less likely to strip the threads...

[RussMcB]

I was kinda thinking the threads were not worth trying to save. I'm assuming all new fasteners will be used when reassembling. In other words, go ahead and smack the crap out of the bolts/nuts. :-).

[DaveW]

I was kinda thinking the threads were not worth trying to save. I'm assuming all new fasteners will be used when reassembling. In other words, go ahead and smack the crap out of the bolts/nuts. :-).

I agree with not re-using, but I was thinking of a better chance of getting them out (part of the impact load is transferred to the thread end, and the thread end doesn't get directly hammered, so maybe easier to get the hex off than the nut) before the thread end of the bolt stripped/flattened and made it worse to get out.

[swiftdrivr]

I think I have figured out why I'm having trouble. I managed to get one of the bolts out. See below.---Jim

[DaveW]

I think I have figured out why I'm having trouble. I managed to get one of the bolts out. See below.---Jim

Then pressing them out is the solution

[swiftdrivr]

Pressing does indeed seem to be the solution. 12 tons of hydraulic pressure beats a sledge hammer. Next question; Is it necessary to reassemble with press-fit bolts, or would standard bolts as used in my 215s work safely? Anyone have an opinion?---Jim

PS; The down side is, I have no way of telling when the bolt bottoms out. They are in a hole. The press ram obscures the top, and the support piece prevents measuring from the bottom. I surely can't snug them down with the nut, considering the pressure required to insert them. It would seem the likelyhood of going too far and cracking a center would be high.

[DaveW]

Pressing does indeed seem to be the solution. 12 tons of hydraulic pressure beats a sledge hammer. Next question; Is it necessary to reassemble with press-fit bolts, or would standard bolts as used in my 215s work safely? Anyone have an opinion?---Jim

PS; The down side is, I have no way of telling when the bolt bottoms out. They are in a hole. The press ram obscures the top, and the support piece prevents measuring from the bottom. I surely can't snug them down with the nut, considering the pressure required to insert them. It would seem the likelyhood of going too far and cracking a center would be high.

It is probably not necessary to use the splined bolts, as long as the substitute bolts fit tightly and locate the components properly. A loose fit would allow possible runout. The splined bolts were probably used to speed up the assembly process by keeping the bolts from turning while tightening the nuts from the rear.

Also, I would bet that the splined bolts originally were pulled tight using only the nuts to pull them in. Otherwise, in this application, I see little advantage to using them. Pressing each one in individually would have been a tedious process.

[Jonathan Hirst]

Without a close inspection my gut reaction would be to ream the spline grooves away and eliminate the stress risers created by those splines.

That would require using a larger bolt however which may not be feasible with the counter sunk head.

Jonathan