Loose Nuts

safety
wheels
porsche
911
#1

Hello all - new to the forum here.



I have a bit of a dilemma that is ultimately a safety issue. My favorite car guys had a big brain fart last week and did not torque my lug nuts after mounting my new tires. This is a specialty shop with a well-earned sterling reputation.



50 miles later, nearly lost a wheel - thought I had a flat & could see it wobbling in the rear view. On both rear wheels, the stud holes show some damage, a little “wallowing out”.



The wheels torque back down tightly, and my car guys say they are OK. I love my car guys, but I am not so sure about this. Is any wallowing OK? I am taking the car to high performance driver’s ed this year (race track driving) so it will see more than “normal” road use if you know what I mean and I think you do :slight_smile:



I know I am “entitled” to new wheels since these are damaged, and they have assured me they will make it right, whatever it takes. But to be honest, these are 20 yr old wheels original to the 20 year old sports car, and if they are safe, I actually prefer to keep them.



I think maybe I should get a 2nd opinion - in the meantime, your thoughts?

#2
Make model and year?
#3

although more vehicle info would be nice:

and are these alloy or steel?

i would be more concerned with the studs having been chewed up rather than the rims getting ‘wallowed out’.

#4

If there is noticeable damage to the wheels in this area, their strength is compromised. I wouldn’t risk it. Have the wheels replaced.

#5

To me, it would depend on just how bad they’re wallowed out and without seeing the damage there is no way I could be certain of anything.

If the car were mine, I would use some Prussian Blue on the lug nut taper and check the fit against the taper in the wheel. If there’s not a lot of Blue transferred to the wheel then the wheels would make me a bit antsy too; especially on a sports car hitting what I assume is a road course track.

You might also consider this. Maybe it’s possible to have a machine shop clean up the taper by cutting a new taper in the holes and then using lug nuts with a larger taper to make up the difference.
???
Hope that helps.

#6

1989 porsche carrera 911, wheels are the stock Fuchs which I am pretty sure are alloy

#7

Yes I think I really need to get in there again with somebody who knows their stuff, and assess the studs, and even the hub, for possible damage, in addition to the wheel itself.

#8

I’m taking the car tomorrow afternoon to get the wheels off, give them a spin on the wheel machine & see how they do, and eyeball the wheels, hubs & studs with somebody who knows waaaay more than I have already forgotten about cars & wheels. I’ve got one crappy photo, attached.

Thanks for all the replies.

#9

If the wheels are mounted using a lug centric design, then any amount of wallowing would be unacceptable IMO. No matter what, the lugs that were subjected to the abuse required to wear away a potion of the wheel should be replaced. Especially in light of your expectations for spirited driving in the future.

Considering a professional shop made the mistake, I’d settle for nothing less than a full repair. They can look for replacement wheels at their own expense and replace all of the studs. They’re getting off cheap compared to if you had been in an accident due to their negligence…

#10

i thought ALL modern wheels were lug, versus hub centric?? not so?

and which is more important, good, un deformed, un stretched studs; or the beveled holes in the rims?

#11

All of my vintage rides are lug centric. All of my newer vehicles are a combination of hub and lug centric- the lugs have corresponding mating rings in the wheels and the hubs have an almost interference fit to the center opening of the wheel.

The vehicle in question is an '89 and I have no first hand knowledge of the wheel mounting scheme…

#12

Can you point me to some information which would explain the two designs (lug- and hub-centric) so that I might be able to determine what I’ve got?

#13

The shop must bite the bullet and replace your wheels and studs,it is unfoutunate for the shop,but you must be made “whole again”. I personally whould drive on but I can’t put my standards upon you.

The racing thing bothers me as the stress level goes through the roof. You will get the wheel issue resolved,the shop should try to stay as your mechanic because when you start racing this car (or any car) you will be seeing them much more.

Old guns should be admired and not fired and old cars (even Porsche which were probably the closes’t thing to a street race car ever made) should not be raced,your getting my personal views and all my points could be argued,except the point you should be made “whole” again,well I guess that could be argued but I will not back down on that one.

#14

These are great guys who made a (big) mistake. I’m taking them at their word they’ll do whatever it takes to make it right, and as soon as I have my head around the details I will let them know what “whatever it takes” is. Fear not re: racing - I have no “racing” ambitions - my aim is to learn well how to handle this awesome and powerful (compared to my usual ride) sports car, to learn the limits of the car, and to work on my driving and handling skills in an intentional, controlled environment.

#15

http://www.miata.net/garage/hubcentric.html

If you google on either term, you will get a number of hits.

Basically, if your wheel center hole fits tightly around a protrusion from the hub, you have hub centric wheels. These are the most popular design today. I noticed you have OEM wheels. If you had aftermarket wheels, then it might be more likely that you have a universal design that might require centering rings to insure that the wheel isn’t relying completely on the lug for centering.

If it were my problem and especially if I intended to race it, I’d have it fixed properly. My 2c.

#16

Just from what I can tell from the pic the damage does not look that bad to me.
It would seem to me that it would be a simple matter for an auto machine shop to clean those tapers up with a countersink bit.
Prussian Blue could be used to check the fit of the taper on the lugs against the newly surfaced taper on the wheels. If there is a good contact pattern as shown by the Blue then I don’t think there will be a problem.

I’m a fan of total originality on many cars so my preference would be to keep the original wheels on the original car.
(Cool car. The 911 Carrera is my absolute favorite German car.)

#17

I am so torn. I will have to see what my 2nd opinion later today reveals about the damage. On the one hand, I hate giving up the wheels that are original to the car if they can be safely kept. On the other hand, I just do not want to be having to check & torque every time I get in the car, and I sure don’t want to be worrying about my wheels flying off as I learn to carry speed into turns on the track.

It’s also been suggested that if I ever wanted to change my wheels (go back to truly stock black-centered Fuchs - mine are chromed and technically not “correct”), I would not be able to sell these as they are “damaged.” Would you buy this wheel for your 911? Yeah, probably not.

I’ll be back with an update later tonight. Time to go torque my lug nuts for the 100 mile drive!

#18

Thanks, that was very helpful, as was the Google search i did before I came back to see your reply :slight_smile: I am learning a lot here. I did not mention that I am running 29mm (appx 1") spacers on my rear wheels, with specialized long studs to safely accommodate them. Here’s a photo taken during my recent rear brake pad replacement - rear wheel, spacer off:

#19

Call it “racing” call it “pre-running” call it “learning to drive your car to its limits” you will be seeing a mechanic more, you may no want to use those pristine new alloys for this purpose although they were designed for it,with “performance driving” being the domain, the coorespondence being “one day at the track”, “looking good” is not in the range very long

#20

My vote is with those that say your wheels and your studs need to be replaced. It you’ve taking this thing to high performance drivung school you’ll be placing stresses on it beyond what it normally sees. You’re risking losing a wheel at high speeds while cornering or evasively maneuvering. That could easily manifest itself as your losing the entire car, perhaps even serious injury.

I’d bet the school will inspect your car before allowing it on the track and they may not even allow you to take it out with that kind of damage.