[Ground Loop]

I like to take out each lug nut on any new car, apply some anti-seize compound, and torque them down to spec. Saves trouble later, especially for a roadside swap.

In light of nxm150's nightmare, I thought this would be a good time to ask for the specs. Are they in the owner's manual or just the shop books?

- Torque spec for each bolt
- Head size (Torx?) for tool

I've had tire places slap those nuts on with a V-Twin powered impact wrench.. then I have to jump up and down on some crummy kit tire iron on the side of the road taking their name in vain.

 

[atyclb]

bmw uses the same bolts and the torque spec is 88ft-lbs +/- 7

 

[LotusLust]

as memory serves the spec is 77...but it has been a while since i read the manual

 

[MattG]

Don't some people say to never use anti-seize compound on lug nuts and bolts?

 

[DigitalElise]

Don't some people say to never use anti-seize compound on lug nuts and bolts?

This guy seems to think so... I'd be interested in everyones opinion.
BWM Antiseize on lugs a bad idea...

 

[James A]

I guess I have been really lucky, in 31 years of using a thread lubricant on wheel studs and nuts I have never had a failure. I torque them to spec. with lubricant.

 

[Stan]

>>> I'd be interested in everyones opinion. <<<

Much of this stuff is not properly evaluated through opinion or polling.

Our wheel bolt spec is 77 Lb-ft. It would be a good idea to use this figure. And in the way it was determined, which is dry. Wheel bolts are cheap. If you are worried about corrosion, replace them periodically, don't lube them up or use antisieze. If you track the car, replace them about once a year. It's also a good idea to check torque a few times until it stabilizes in road use. On the track you do it before each session.

 

[Ground Loop]

Doing a search around the internet, it sounds like anti-seize is indeed unpopular on lug nuts. News to me!

I can say I've lost studs to 'bonded' nuts so it always seemed like a good idea. I've never had one spin loose, but I can see how any 'lube' would change the tension on the bolt. The Elise will be my first 'bolt' car, so it might make less sense to use anti-seize there.

I have found several references that suggest anti-seize on the wheel-hub interface surfaces and even the conical taper of the bolt face. That makes some sense too.

I just don't want a repeat of this:

 

[Stan]

>>>I guess I have been really lucky, in 31 years of using a thread lubricant on wheel studs and nuts I have never had a failure. I torque them to spec. with lubricant.<<<

Your comment (above) and mine about checking torque until it
settles in street use are related. Alloy wheels may have "accomodated" the overtorquing by "moving" a bit.

What may have been saving you is the soft, conforming nature of the alloy wheel itself!

If you change your wheels and tires and drive on the street a bit you can check the torque after a day and find that they need to be retightened! They did not loosen as in unscrewing. The alloy wheel moved a bit. If you retorque a time or two things will settle down. Also there is the matter of friction. It's hard to go over this stuff in a live message board format but there is plenty available to read about for those interested in doing so.

 

[doma]

After reading about nxm150's experiance I just went and retorqued all my wheel bolts. For some reason on my car the bolts on the rear left wheel were on really tight ... the other three wheels were not very tight at all. I used the torque wrench to undo the bolts (I know, this is not a way to tell how much torque was used to put the bolts on in the first place but it was an interesting measurement nonetheless...) it took over 100 ft-lbs to undo the bolts on the rear left and less than 40 ft-lbs for the other wheels - cept for one particular bolt on the front right. I retorqued them all to ~77ft-lbs.

I'm amazed at how light our wheels and tires are. V. Easy to pick up and move around.

I used the hockey puck trick the tech at SVAG showed us to lift the car (you put a hockey puck between the jack and the Elise's rear outside (not under the diffuser) lift point) so as not to mar the underneith with my jack's teeth. Lifted one side at a time.

Another note - my bolts had a white chalky substance on their tips. Maybe some kind of lock lube?

anyway-
-dom

 

[ex-M3]

I will reiterate the proper comments already made: Do not use lubricant on bolts unless the torque is set based on a lubrication being applied. As the link states, bolts work by stretching to create a clamping load. A lubed bolt will be overtorqued if no lube is required because a smaller percentage of the torque load is required to overcome friction.

We have this problem on jet engines all the times. We recommend (actually it is more like require) using engine oil on most bolts. Some bolts get molydisulfide or other lubricants in specific locations. Mechanics often do what they feel is right based on their experience, using a different method than the engine manual states, often with unfortunate circumstances.

For critical connections the most accurate method is to measure the strain of the bolt and not the torque.

 

[pianomaniac]

Stan had mentioned BMW 17 mm Hex bolts for the Elise wheels.

1) Are these purchased only through a BMW parts dept. (dealer)?

2) If I were to have these chromed, is it best to only have the heads dipped or have the entire bolts dipped.....or maybe they sell 17 mm bolts already plated?

3) Would these replacement bolts be torqued to the same specs as the original wheel bolts?

Thanks

Ron

 

[Stan]

>>>1) Are these purchased only through a BMW parts dept. (dealer)? <<<

Yup standard, in stock parts, you can even get good prices on them if you shop. I use the black ones.

>>>2) If I were to have these chromed, is it best to only have the heads dipped or have the entire bolts dipped.....or maybe they sell 17 mm bolts already plated? <<<

I think you can buy chromed BMW bolts. But chroming makes them heavier, you need to use soft-lined sockets and there is the hydrogen embrittlement (fatigue life aspect) issue.

>>>3) Would these replacement bolts be torqued to the same specs as the original wheel bolts?<<<

Yes. They are also almost 1/2 ounce lighter, each.

 

[Stan]

>>>er reading about nxm150's experiance I just went and retorqued all my wheel bolts. For some reason on my car the bolts on the rear left wheel were on really tight ... the other three wheels were not very tight at all. I used the torque wrench to undo the bolts (I know, this is not a way to tell how much torque was used to put the bolts on in the first place but it was an interesting measurement nonetheless...) it took over 100 ft-lbs to undo the bolts on the rear left and less than 40 ft-lbs for the other wheels - cept for one particular bolt on the front right. I retorqued them all to ~77ft-lbs. I'm amazed at how light our wheels and tires are. V. Easy to pick up and move around. <<<

You don't have to jack up the car and pull wheels or remove the bolts all the way to do this. When I check torque at an event I just do each bolt in the tightening direction with the torque wrench set properly. Car on the ground parked normally. "Click". Then you go to the bolt 180 degrees across and do it then the remaining pair. Check all 16 in a moment or two. Some folks don't even follow that tightening pattern since the lugs are already pretty tight and most will be fine and very close to one another..

You should also try checking after a day or two of driving. With the wheels cooled off you may find that some bolts need more torque. This is common, nothing is wrong and then the torque tends to settle down and stay stable. Sometimes it takes three efforts to achieve stability. This tends to change to 1-2 times after a set of threads wears in and the wheel finish evens out under the bolt head. When a few need tightening most likely they were still in the safe range. After all when folks have their car serviced they don't bring it back 100 miles later for a retorquing. But you can certainly do this at home. If you do any car events you should have a decent torque wrench and do it yourself personally or by someone you trust and who is reliable.

The white stuff you mentioned is not a loctite or whatever, you don't need that for wheel bolts. Our bolts don't loosen up by unscrewing themselves. They lose clamping force when the clamped item compressive yields (soft aluminum) or when it wasn't there at all (false torque from friction factors) or from other things.

 

[Ground Loop]

Yes. They are also almost 1/2 ounce lighter, each.

Wait until Perry hears about THIS!

Seriously though, sounds like a Sector111 opportunity.. lighter bolts, black finish, and gets rid of the lock-nut hassle. Shinoo?

 

[pianomaniac]

Wait until Perry hears about THIS!

Seriously though, sounds like a Sector111 opportunity.. lighter bolts, black finish, and gets rid of the lock-nut hassle. Shinoo?

I agree......perfect aftermarket item for Sector 111. I think black finish and also chrome finish to match the stock wheels.

 

[perryeyges]

I am trying to locate titanium wheel bolts..
I think Shinoo @ Sector 111 might be the guy..

 

[Stan]

Well for lotsa track time...ditch the wheel bolts entirely and go with studs with separate nuts. Stronger, easier to mount wheels, more accurate tension / torquing due to lower friction and other factors.

 

[perryeyges]

I agree about the wheel studs except if you don't use multiple wheel tire combos. I may just stay with the AO48's on the stock LSS wheels, they're pretty sweet tires.

 

[ex-M3]

I am trying to locate titanium wheel bolts..
I think Shinoo @ Sector 111 might be the guy..

Titanium is not a good choice for bolts. It is subject to galling which means they can freeze in place.