Lost a wheel

A mention of the year and model car would be helpful!

 

And the car is a ............................???????

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Glad you are OK......stock wheel/tire combos or did you have spacers?

 

Andrew, we had a service client who had this happen a couple of months ago..........he'd swapped over to his track wheels and hadn't torqued the wheels up properly

No drive shaft damage in this case but we did have to change the hub, lower wishbone and a few other bits...........on Mondials its the wishbone rather than the brake disc that hits the ground

Can't remember what Ferrari you have but if its a Mondial I've got a big pile of used parts that should save you a few pounds

 

What does that have to do with the question

 

Again.... Don't have any idea what kind of car was involved but we have been seing that in the 308s for 2 reasons.

1. They are all getting to be old cars.

2. The rubber being used today is so superior to what was available when the car was built we are subjecting old cars to stresses they were never intended for.

We as a club (in this area) have had so many wheel and suspension failures that it is the reason we do not allow racing tires in track events except on racing cars. We took a lot of flack for it in the 2004 National meet at Laguna Seca but we have a been doing a pretty good job of keeping cars in one piece.

 

A prisoner escaped from a jail in the South some years ago and stole a car.

In the course of attempting his getaway at speed, a wheel came off the vehicle causing him to ditch the car.

The police reported when coming upon him, he was seated outside the vehicle singing:

" You picked a fine time to leave me loose wheel"!

Maybe a similar case here?

 

Excellent point Bryan, I always think that when folks max out tire sizes to the "Biggest that will fit"!!!

What was it Mike Hawthorn said: "Don't slip the clutch...slip the tires!!"

 

Is point #1 related to deterioration of bearings and suspension bits, or just that the design of a 308 hub isn't up to the stresses of superior new tires?

I guess what I'm asking is whether I can do anything, from a maintenance standpoint, to prevent this from happening?

Also I'm wondering if the OP may have been about a single-spline Testarossa - I've heard of those wheels coming loose if they're not checked. (I know of someone who had this happen here in San Diego.)

 

Both. If I was tracking a 308 I would be having them magnufluxed. Too many of them breaking. Same goes for front lower control arm mounting forks but I think pretty much everybody is inspecting those. Or at least they should be.

 

Did they make any changes from the 308 to the 328 suspension wishbones?

I know there was some recall for something suspension arm related on early cars.

For instance I know on my BB they are a multi piece I believe forged unit held together by bolts, on TRs they went to a stamped one piece wishbone.

 

It's not clear what broke? The axle?

Bill

 

Brian,

I am thinking about tracking my 308, big sticky Goodyear DS DGs, bars and springs; Should i be pulling the axle stubs for magnaflux?? (77 308 w/ 27k on the clock)

Would a good shot peening of the stub help significantly. I have heard that the stub axle is a weak link, Do you have a rough service life guess for the part, how many track events or racing miles before replacement or magnaflux. I have no clue.

Could you tell me a bit more about the front forks and what can be done to correct the situation. Darn, I had them off to do the bushings - wish i had known that they were a weak link and what to do about it.

Mired in ignorance/inexperience, yet again,
chris

 

Well this has happened on just about every car ever tracked. People do not realize how much a properly torqued wheel can come loose from the pressures and heatcycling on a track. There is actually, often times warning but we ignor it. We think it is rubber pick-up or a thrown wheel weight. It is always wise to exit the track to check out any weird feelings. in the car. In this case we still do not know if the problem was: 1) loose wheel, 2) failed part. Mondial rear stub axle/hubs do have a history of problems and were recalled or upgraded at least once that I know of. So...if the tire passed the car my guess would be tire came off the hub. I have seen ferraris with broken hubs and usually the wheel hub is still bolted and the broken part allows the wheel to get shoved up on the bodywork and makes nice body damage too and is more likely to trap the wheel in the fenderwell rather than allow it to pass the driver.

 

Too much beer on a Friday night to get the calculator out, but I'm guessing more stress in the system than what it was designed for...

 

Cool the picture came just as I posted. Looks like a clean break...no operator error. Amazing the wheel was flung out with almost no body damage.

 

No I don't think so. The QV uses TRX of the day and was I think 16" 255 in rear but perhaps a bit less sticky than today but honestly the pirelli P zeros that are stock 348 tires are like marbles so I don't think extra grip is a significant force. FRom the look of mondials with 348 wheels vs mondial trx wheels I don't think the force by the modest change in offset does much either.

 

Where did the caliper end up?

 

Actually, it was a bit of a bad joke.

Any part failure is because:

actual stress > designed maximum stress

I guess I was looking at too many failed parts today...

 

Maybe its just my eyes but, could there be signs of rust along the leading edge of the wheel arch? The wheel well looks like it has see a few winters. If so, rust may be festering in other near by sensitive areas.

 

It's been known to happen in various venues for various reasons.

http://www.youtube.com/watch?v=MeI4R0ko7ns
http://www.youtube.com/watch?v=7hwMwh8Am9o
http://www.youtube.com/watch?v=iw2m2XJxUR4

There have also been a rash of split rims in the ricer world -- wider rims with the drive points at the extreme outer edges may be the problem, there.

It's amazing what you can find surfing youtube. Remember that joke about "my lug nuts take more torque than your honda produces"? : http://www.youtube.com/watch?v=wkS0our54YE
(For some reason, I found this pretty funny.)

 

So, what is the prudent course of action??

Pull the axles every 10 track events and have them magnafluxed??

Would shot peening significantly extend part life??

Is there any other treatment, other than replacing with new, that would take care of this problem.

The problem seems to have been mentioned often enough, that we should do something?

curious,
chris

Daniel, is that the caliper, sitting on the lower controll arm??