Okay, here are two issues that have stuck their ugly head up recently.

Last month I took a new 07 MCS to Carolina Motor Sports Park for a track weekend. The car had 750 miles. The day before I had new lightweight wheels and tires installed but still used the 14mm oem lug bolts.

I torqued the bolts at 90 ft/lbs before the start of each of the four morning sessons. None of the bolts moved, period, so I thought this is good. After lunch I didn't check the torque before the first run. The front end felt loose in turn two so I limped in thinking I my have cut a tire. Just as I came off the track and behind the wall the car came to a big halt. When I got out to check what was up a single bolt lay on the ground and the driver's side front tire was standing upright in the tirewell with no visible damage except the lug bolt was stripped as were the three others we found on the track. The hub holes were all stripped as well with some of the treads just laying in the hole. The wheel was found unusable because it had been punctured by the calipher as it feel down...the tire would not hold air.

After installing a new hub brought up from Mini of South Atlanta and being unable to obtain new 14mm bolts from anyone in the Southeast I removed one bolt from each remaining wheel and limped back home to Georgia with no issues on a borrowned wheel and tire.

One other issue of note was I learned plastic concentric rings were used. When I had the wheel replaced I had all the plastic rings replaced with metal.

Next issue and the real reason why I bring all this up...I had been driving in the North GA moutains today on a very gentle cruise with the wife in my 05 MCS Cabrio. We got back within about 25 miles from home when the front end started to feel loose...very much like my 07 on track day...I thought oh hell, and started to pull off the road into a service station when the driver's front wheel came flying off and barreling toward the front of the store glass. Lucky it hit the brick part instead of the glass and no parked cars but there we were with the frame setting on the ground and a tire well pretty much shot.

Our MINI had after market wheels and lug bolts that were less than a six months old but new tires had recently been installed...maybe 250 miles on them. Two bolts had come completely off still in the center cap, two bolts completely sheered off.

Any guess as to what is going on? here are a few pictures

 

Wow, sorry about the mishaps.

The torque spec. for 14mm lug bolts is 103 lb-ft.

New aluminum wheels (especially cast wheels) need to be re-torqued after the first 40-100 miles. The aluminum compresses and the bolts get loose.

I'm guessing that the shearing happened when the bolt was partially out and perhaps other bolts gone.

P.S. Were those Palo Uber lug nuts?

 

Wow, thats crazy. I have no clue whats going on there. But i have come close to experiencing the same thing. I had just done a tire rotation on my own, torquing to 80 i think. I participated in a test and tune the next day and an autocross the day after that. The test and tune on the first day was pretty rough on the car, and on the way to the autocross the next day, i felt severe vibrations coming through the steering wheel. I pulled over immediately and checked out my wheels, and the lugs on one of my wheels was so loose that the lugs fell as soon as i touched them. It was not very assuring.

 

not sure wat happened, but i torque 88 to 90lbs and retorque again
after 4-5miles drive. usually after that, the lugs do not need to be
retorqued.

also, i only use factory lug bolts on my MCS. on some wheels you need
to remove some of the paint in the lug bore so that the lug has something
to bite into.

 

Call mentioned 14mm bolts. Are you using 12mm or 14mm? With the change to 14mm MINI increased the torque requirement to 103.

 

never happened to me in my MINI but it DID happen when i was driving a corolla back in the day... turned out i left one of my hubcentric rings off. maybe yours did too?

 

After the track day I came over on NAM and noticed someone's post of the 103 on the 14mm. I told my wheel/tire vendor of this and he looked surprised. He wasn't aware of the change on torque with the 14mm. They replaced the wheel and changed out the plastic concentric rings with metal at no charge. I ate the other repairs and was satisfied. I really should have checked the torque on the 07 after lunch even though I checked the previous four times. You have to check every time, period. I learned no short cuts for track days.

Now as for the 05, same vendor and plastic concentric rings, too. I'll get them all changed to metal but I think I need to have a talk with my tire vendor. I don't think I should have to check the torque right after the new tires are installed after only 250 miles but then I may have to start loosening my bolts and torquing them myself from here on after. I'm thinking I may have a problem with my vendor. I'll see what he has to say.

As for leaving one of the concentric rings off, no it was laying in the road all torn up! I'm guessing it stayed on the hub after the wheel came off and then fell on the road when the rotor hit the road.

Call

 

what kind of bolts are those? they don't look stock.

one thing to note....thread pitch. perhaps what you used wasn't correct (the MINI 14x1.25 is rare). that would cause the issues you had. an RX7 learned this the hard way on an auto-x course this summer (lost all four wheels...it's on youtube).

 

here it is if you want to see http://www.youtube.com/watch?v=-CuZyAnEAvM

 

It's not a MINI thing, and it's not a vendor thing either. You need to retorque to the proper spec after 50-100 miles. If a bolt is going to come loose, 250 miles is too late.The fact that they're not hubcentric does not help matters. I'm not saying you shouldn't use aftermarket wheels, just that you need to be even more careful....

 

or maybe an incorrect part thing. see my post above about thread pitch of the bolts used.

 

Those don't appear to be stock bolts........?

 

we need to know what type of bolts those were? Brand name, etc. They look to be the typical Gorilla brand cone seat lug bolts. Gorilla only lists a 14x1.5mm app for VW and MINI uses an oddball 14x1.25mm

 

You mean MINI uses 14x1.25mm right?

you listed 14x1.5mm twice.

 

yes....that's what I get for browsing while on a conference call (and I only put it once...both other times I got it right)

 

I had my fronts loosen up at a recent track weekend at Road America. I had torqued my wheels the day prior to the event, long after installing my after market rims. They didn't require tightening after my initial 100 mile break in (a few thousand miles ago).

I had done four 20 minute sessions on Saturday, and all was well and they were still tight. On the 2nd session of Sunday is when I noticed a vibration (such as a warped rotor). Limped off the track, and I discovered loose lug bolts on the fronts. They didn't strip or elongate the bolt holes in the wheel, so I was able to simply jack up the car, rotate the wheels, and tighten up again and all was well for my 3rd session. They didn't loosen after that, nor upon inspecting them the last few weeks periodically.

I suspect that the intense heat and cornering forces that are being generated simply require more scrutiny. I've also bumped up the torque to 90 lb/ft for all 4.

 

you sure? cause my dealer torqued up my lugs to about 250lbs last time. lol!

mine are the smaller ones since my car is old...

 

Happened to me at my first autocross. I never really use a torque wrench but coming from a honda I probably wasnt cranking it enough. I noticed pretty instantly what it was before I drove anymore. The vibrations made it pretty obvious and a stopped and tightened up.

 

Purchased MB Wheels Spark 17s for a new 05 MCS two years ago. When I sold it I moved them to my 05 MCSC and have had no issues until now. The bolts came with the wheels and they do look just like those Gorillias as pictured. I'm sure they are the 12mm as the prior to 07 Coopers use. I always torque at 90 ft/lbs.

My issue is these are not new wheels and bolts. It they had been I can see retorquing at the 50 mile mark or so. I had just had new tires put on them and had driven about 250 miles...didn't think a retorque was needed at this point. No aggressive driving during this time period either.

I'm trying to determine if two bolts worked loose and the extras stress on the other two bolts sheered them or if two bolts were stressed from over torque with the air gun from the tire dealership and then sheered causing the two other bolts that may not have been over torqued to loosen.

Another question I have is in concern of the plastic concentric rings...any advantage of using metal instead?

Call

 

The only real difference between the plastic or metal hub rings is the possible heat damage done while on the track or during an extended "spirited" drive.....I have plastic rings and have done track days with no problem, all though the track I go to is not a heavy braking one so I don't get the higher temps that some others would see.

 

I re-torque after every track session. I know that makes them too tight since things really get heated up, but I'd much rather have them be too tight than too loose. At the end of the day, if I don't loosen them while warm (prior to changing tires/pads) then it's really difficult to get them loose.

mb

 

Retorqueing should occur after cool down and before next sesson on the track.

Call

 

Several things come to mind:

Plastic concentric hub rings were too thick and did not let the wheel face properly seat against the disc hub.

Improper torque at 90 ft lbs ..... should have been 103 ft lbs.

Wheel lug taper angle not exactly the same as the lug nut taper.

Note .... If antiseize is used the torque must be increased 10%.

 

So sorry to hear about all these problems. It does scare me when I see a tire installer grap that air impact wrench and just start whacking the lugs in. Boy, if you changed to an aftermarket lug with the wrong pitch and the installer just whacked them in with the impact wrench they would have cross threaded and held temporarily. At the first sign of heat or stress boom, there going to strip-out. Good luck and keep us informed.

 

Yea, but sometimes things aren't all cool by the time you need to get out there.

mb