Torquing Lug nuts???

[1sttruck]

A former coworker received a call from her daughter, who had a flat but couldn't the wheel off. It was raining hard and she on the side of busy road. The coworker couldn't get it off either so she called her husband, and in spite of being a large gentleman in good shape he had a very hard too.

A little bit of anti-seize goes a long way towards making life easier down the road. If you think otherwise then wire brush all the studs on your wheels, caustic etch them with some oven or engine cleaner, and then degrease them. Make sure that the lug nuts are degreased too, and then use salt water instead of anti-seize :^)

 

[Todd_96SRV]

If the wheel & tire assembly is properly maintained, IE, dismounted occasionally for inspection & rotation, you would never need to use Anti-Seize under most typical applications. Wheel & hub faces are typical areas where corrosion effects can be curbed with the use of an Anti-seize.

 

[Jimbo]

There are very good engineering reasons for using clean, dry threads and the factory recommended torque. Preload, that is the clamping force is what is desired. Fastening torque is a means to that end. Having worked for an aerospace fastener company, we used thread lubes to vary the preload resulting from the same tightening torque.

The other important factor is fatigue life. If the fastener is not kept under sufficient tension at all times, it might fail. I have seen undertightened lugs break due to metal fatigue.

140ft-lb with clean, dry threads, with a clean surface between the wheel and hub, is the only way to be as safe as possible.

 

[Kestas]

Is Boeshield a plastic shim used between the wheel and hub? We've had problems with certain truck fleets that experienced wheel-offs because they either used a plastic shim or painted the hubs. This organic layer can take a set, resulting in loss of clamp load.

 

[Kestas]

Is Boeshield a shim used between the wheel and hub? Be careful with that product. We've had a few trucking fleets experience wheel-offs because they either used a shim or painted their hubs. The organic layer takes a set, resulting in loss of clamp force.

 

[Audity]

Kestas, thanks for the heads-up Actually, though, Boeshield is a protectant that comes in a spray can. It was developed by Boeing as a corrosion preventer for aircraft and maybe other uses. It goes on fairly thin, then dries down to a waxy film. It's good stuff.

 

[Audity]

To follow upp on Todd's post, I find Boeshield (sp?) very useful for areas like wheel and hub faces. In fact, I've used it on wheel bolts and lug nuts on occasion.

 

[Matt89]

Interestingly, I've rotated tires many times without using a torque wrench...just tightened them 'enough', whatever that means.

I also watched a guy put my tires on with an air gun. Didn't know at the time that he wasn't doing me a favor.

Anybody else just tighten 'by feel'?

 

[labman]

I tightened by feel for many years. When my son was a teenager, we watched a TV program* together on Saturday mornings where the guy explained modern cars are so flimsy, you can damage them by over tightening or unequal tightening and you should use a torque wrench. That wasn't quite how he put it. I have used a torque wrench since then, and now torque to 80% with antisieze.

I watch guys tighten lug nuts with air wrenches all the time. The car flies into the pit, the guys go over the wall with their air guns and have the tires changed before the tire store could have the lift up. Perhaps they use some special, expensive equipment? I have never noticed them taking time to replace a broken stud. Maybe they are better than the ones on my Cavalier?

*Not those idiots on Car Talk.

 

[johnd]

I can't speak for every idiot with an air impact wrench but at Discount Tire (where I have been going the last few years) and probably other places, there is now an torque extension that will not allow the lug nut to go tighter than a set amount-due to flex, I guess. Hopefully the tech will know to choose the correct extension.

 

[ikeepmychevytoo]

Enough tightness is one cardinal safety requierement. For emergency situation I'd rather have four lugs at specified torque rather than having undertorqued five.

For the sake of sensible design; While there are spare wheels why no spare lugs on some cars? Lug nuts are cheap! I'd buy a few while I'm still mobile, put them nearby the spare tire and torque them to the 140ft.lbs everytime without a worry. If they are flimsy I'd torque progressively; at first cycle torque them to the 70~80% of the spec. torque, then torque to the full spec. in the second cycle.

 

[Chris B.]

Did I do the math right? 80% of 140 is 112? I torqued to 120 because the threads seem to have some old grease on them. Maybe old antisieze? So for in a week at 120 all seems fine.

 

[-Clayton-]

Just use some red loctite and tourque them too 300 ft lbs. No dont do that im just joking.

 

[ikeepmychevytoo]

Wet torque compansation is another thing, I bet, even the plating material is taken into consideration before giving out the "specs" at the design stage. So I can not throw numbers for that. But well, as others pointed already, less for the wet. Some say, as a rule of thumb 80%. This is just a coincidence with what I tried to describe.

What I mean you follow the "star pattern" two times for each wheel, setting torque lower for the first (~80%), full for the second. Time consuming but easier on the lug nuts. I oftenly see calling for such practice for more delicate parts, where contraction, flex, accuracy etc. is an issue. Basically, torquing progressively in two steps has the similar reasons why we torque them in a star pattern.

 

[Bret Chase]

" watch guys tighten lug nuts with air wrenches all the time. The car flies into the pit, the guys go over the wall with their air guns and have the tires changed before the tire store could have the lift up. Perhaps they use some special, expensive equipment? I have never noticed them taking time to replace a broken stud. Maybe they are better than the ones on my Cavalier?
"

they use 5/8" studs, which are far and away stronger than the ones on your cavalier.

 

[andyd]

the only time in 40 yrs of wheelswapping that I have lost a wheel was due to a rim failing and pulling through the lug nuts. (old , rusty rims) I coat the hubs with chassis lube to prevent the alloy wheels from bonding.

I dont use a torque wrench, and I grease the lugs a bit. I use the lug wrench to tighten the lugs in a star pattern repeated at least 3 times. No problems yet.

 

[Matt89]

A quick note...

I bought a torque wrench, and used it to check the torque on the spare tire that rides along on the back of my CRV.

The first stud I tightened (of 3) actually broke right off the spare tire bracket. Surprised the heck out of me because I really wasn't cranking down on it as far as I could tell. Not sure if I misused the wrench or weakened the stud when I tightened it 'by feel' earlier.

The torque wrench clicked properly (40 foot pounds) on the second and third studs, but not the first one that I did. Of course I failed to follow the directions about cycling a new wrench a few times before tightening to the full value. Live and learn I guess.

 

[9c1]

" watch guys tighten lug nuts with air wrenches all the time. The car flies into the pit, the guys go over the wall with their air guns and have the tires changed before the tire store could have the lift up. Perhaps they use some special, expensive equipment? I have never noticed them taking time to replace a broken stud. Maybe they are better than the ones on my Cavalier?"

Yes they do have special, expensive equipment. The jacks and air wrenches are custom made for both speed and endurance. They do replace the wheel studs periodically -- ALL of them. They do it back at the shop between races. The race shops around Charlotte have tours. Take one some time. I was able to tour DEI. I enjoyed it even though NASCAR is not one of my big passions. The tours are great for any gearhead.
Terry

 

[labman]

Actually I am an IRL fan. Likely much the same

 

[Crashbox]

YIPE! Putting anti-seize on wheel lugs scares the living daylights out of me!!! I'll either use a torque wrench when necessary ('95 Civic) or by 'feel' (my '75 Dart Sport and '77 Chevy pickup).

In the past, I always tightened by feel and never had problems. But anti-seize, nope, never, not on my vehicles...