Loose Lug Nuts

[davepl]

I bought myself a set of Torque Sticks for my impact gun but have so far always checked them with a torque wrench afterwards. They're always spot on - but having had the aforementioned wheel come off, I'm a little OCD and check them manually still.

[garyd1961]

Originally Posted by davepl

If you're wondering what happens if the lug nuts come all the way off... it sucks!

Apparently they put new wheels on just before selling it and didn't hand-torque them, and I wasn't in the habit of checking new cars for tight lug nuts. I am now though!

My cousin was looking for an S10 to put a 427 stroker in. He found a 87 that was really clean and already had a sb 400 and ford 9 inch in it. He removed the 400 and installed the 427 and was on the way to the muffler shop when the rear wheel came off. It didn't do as much damage as yours but man that sucks.

[davepl]

Originally Posted by garyd1961

My cousin ... was on the way to the muffler shop when the rear wheel came off.

That's funny, that's exactly where I was going when mine came off! The sounds I heard that -might- have tipped me off I wrote off as the loose exhaust I was on my way to have fixed!

[In The Ten Ring]

Once in traffic on Independence Blvd east of Charlotte, NC (Matthews) I saw a pickup lose its driver's side rear wheel! It literally launched some 20 feet straight up into the air and came bouncing down, fortunately it didn't land on an other cars in traffic. The truck's hub sat down onto the pavement but the truck just pulled into some business entrance and stopped.

*The light turned green and I had to go forward, else I would have checked on things and offered my help.

[toolboxchev]

Originally Posted by davepl

If you're wondering what happens if the lug nuts come all the way off... it sucks!

Apparently they put new wheels on just before selling it and didn't hand-torque them, and I wasn't in the habit of checking new cars for tight lug nuts. I am now though!

X2 on hand torque and then re-check after a few miles and again after a few hundred.

The guys at most of the big chain store like to impact them on. And thats a big no-no in my book. One of the many reasons why I prefer to do most of my own work.

[In The Ten Ring]

Originally Posted by toolboxchev

X2 on hand torque and then re-check after a few miles and again after a few hundred.

The guys at most of the big chain store like to impact them on. And thats a big no-no in my book. One of the many reasons why I prefer to do most of my own work.

I do all my own tire rotations also, I don't even own air tools.

[Gromit]

http://www.boltscience.com/pages/josteffect.htm

No need to click the link because here is the full text: (unless you want to see the diagram) ha ha

The Jost Effect:
Nut sliding on joint surface
The vast majority of threaded fasteners retain their preload because of friction present on the thread and head contact surfaces that resists self-loosening. It was thought that once relative motion occurs between the threaded surfaces and other contact surfaces of the clamped parts (because of a tangential external force being applied to the joint), the bolted connection would become free of friction in a circumferential direction. More recent studies have shown that under conditions of transverse slip there is a small, but measureable, force resisting circumferential movement.

In the above diagram, the red arrow shows the joint surface moving under the nut. When slip occurs at the thread interface as well as the nut face, the frictional resisting forces in the circumferential direction reduce to a very small value. The Jost Effect is the name given to the reduction in the frictional resistance that occurs in a direction different to that inwhich slip is occurring. This effect is used in many applications including the removal of corks from bottles. If the cork is first rotated the force needed to pull the cork from the bottle is significantly reduced. Several machines and applications use indirectly the Jost Effect, for example floor polishing machines, the machine being easier to move when the polishing disk is rotating. Nut sliding and rotating on a joint surfaceIt is also the fundamental reason why threaded fasteners experience self-loosening. Frictional resistance is first overcome in the transverse direction by slip occurring on the joint resulting in the frictional resistance in the circumferential direction reducing to a small value. The torque acting on the fastener in the loosening direction (as a result of its preload) that when coupled with the Jost Effect results in self-loosening occurring. This is illustrated in the diagram.

The term is named after the Institute that completed research into this effect, the Jost Institute of Tribotechnology at the University of Central Lancashire in the UK.

[notsolo]

I think ( engineer_ gregh Original post ) is on to something, not to disregard all the other possibilities, cone shapes, flat wheel mounting surface etc. I bought new chrome lug nuts 20+yrs ago from western Auto, never thought a thing about it until I go to mount them, the threads are sloppy. Thread them on 1/2 way and see if there is any play wobble from stud to nut. this is a pretty serious part of our trucks, don't take a chance on inferior parts.

[davepl]

Originally Posted by In The Ten Ring

I do all my own tire rotations also, I don't even own air tools.

Did you see my post about torque sticks? I use them and have for years, but since losing a wheel (not related to my own work) I have always hand-checked them with a click-style torque wrench.

They've always been right. That is, after all, what they're for - to limit snap torque. But you need the stick, or it's wrong!

Lug nuts + impact gun == bad mojo
Lug nuts + impact gun + torque stick == seems perfect

[Gromit]

It was late last night when I posted about the Jost Effect so I didn't comment then but I wanted to add what I think might be the reason we see these lugnuts loosening.

Assume the wheel is just sitting square on the hub and studs with no lugnuts and with no weight on the wheel. You could grab that wheel and tire at nine and three o'clock and be able to rock it just a degree or so up and down, right?

In other words there is a little play due to the studs being smaller than the holes in the wheel.

And lets assume this is the stock steelie because on those wheels the hubcentric feature still keeps the wheel reasonably centered, even though the wheel can still move that one degree in each direction - lets call it up and down - relative to the studs.

So I think that the Jost effect might be coming into play during driving as rotational forces between the wheel and hub change or switch directions between clockwise (acceleration) and counter-clockwise (braking) - and with hundreds or thousands of such cycles the lugnuts will (slowly at first but then quicker as the clamping force is lessened), come loose.

I'm thinking that the factory recommended 65 foot pound figure may not be enough - but with a 7/16th stud I would worry about exceeding say the ASTM standard for that size bolt and thread count..so for now I am upping it by five pounds and just watching them more..especially after carrying heavy loads.

So that is just a guess and hopefully someone who really knows will speak up and educate us all - and thanks again to Gregh for posting this thread and getting people to check their wheels; it really was a good topic to post in terms of saving people potential grief..

[Gromit]

I just remembered that the lugnuts have a cone seat and that does not fit with my previous post and theory that there is enough play for the Jost effect to come into play... So I am back to just clueless as to why the lugnuts are loosening.

I think notsolo has a better theory and will check mine for that wobble due to sloppy thread.

I did check my VW Vanagon and Mercedes lugnuts today and those had not budged in years and were still tight so this is a C10 thing.

[toolboxchev]

Originally Posted by In The Ten Ring

I do all my own tire rotations also, I don't even own air tools.

Every time I let a shop do my rotations I end up with dings in my rims. I too own no air tools.

I worked for Firestone for a period of time, It was amazing how many people came in for an oil change and we had to replace their entire oil pan due to Jiffy Lube using an air tool on oil pan drain bolts.

Amazing I tell you!

[Front Range]

Ok garyd.

ET extended taper Lug nuts, much better fit vs plain acorn. Torqued to 85 ft lbs.

[Front Range]

Some of the minor damage. Blew off the lockout end, bent fender, ground backing plate and some off the disc rotor. Not bad considering the speed and impact. Everything else in the suspension, steering, and body looks ok.

[leftybass209]

Originally Posted by davepl

I bought myself a set of Torque Sticks for my impact gun but have so far always checked them with a torque wrench afterwards. They're always spot on - but having had the aforementioned wheel come off, I'm a little OCD and check them manually still.

Spot on. Torque sticks are okay at best. I love the idea of them, and have used them myself, especially when i'm in a hurry. However, there's no time saved worth it when compared to the danger of a wheel coming loose. Wheel torque is often one of the most neglected things on a vehicle next to oil changes and tire pressure.

There is no supplement for a good torque wrench and an extra 5 minutes.

[davepl]

Originally Posted by leftybass209

Spot on. Torque sticks are okay at best. I love the idea of them, and have used them myself, especially when i'm in a hurry. However, there's no time saved worth it when compared to the danger of a wheel coming loose. Wheel torque is often one of the most neglected things on a vehicle next to oil changes and tire pressure.

There is no supplement for a good torque wrench and an extra 5 minutes.

Pretty sure that's -all- the big tire stores like Les Schwab use, and if there were any real risk, they simply wouldn't be able to as there would be too many bring backs, warped rotors, wheels falling off, and so on.

Like I said, I still check them, but I think it's redundant. I've never had the torque stick be wrong yet!

If nothing else it saves some work and prevents you over-shooting by trying to pre-tighten them with an impact.

[leftybass209]

Originally Posted by davepl

Pretty sure that's -all- the big tire stores like Les Schwab use, and if there were any real risk, they simply wouldn't be able to as there would be too many bring backs, warped rotors, wheels falling off, and so on.

Like I said, I still check them, but I think it's redundant. I've never had the torque stick be wrong yet!

If nothing else it saves some work and prevents you over-shooting by trying to pre-tighten them with an impact.

Torque sticks are a wear item, just like impacts. Degradation is questionable as to the brand and longevity, but I've not only seen broken torque sticks, but I've had them very +-20ft.lbs. just like a torque wrench needs to be calibrated so often, torque sticks need to be checked for accuracy.

[davepl]

Originally Posted by leftybass209

Torque sticks are a wear item, just like impacts. Degradation is questionable as to the brand and longevity, but I've not only seen broken torque sticks, but I've had them very +-20ft.lbs. just like a torque wrench needs to be calibrated so often, torque sticks need to be checked for accuracy.

Tangential to this discussion, but not worth a new thread: does anyone know where you can take a Craftsman torque wrench to be recalibrated? Sears doesn't do them in house (ie: you can't just take it to the store last I checked). I'm overdue!

[dmjlambert]

Today felt like a good day to check. Found one lug nut very loose on each of the front wheels, and tightened them up.

[ga-stepside]

Originally Posted by engineer_gregh

I've installed 20" Boss 338's on my longbed. Yesterday a guy pulls up next to me at a red light and informed me that my left front wheel looked to be loose. After I initially installed them I went back and checked for loose lug nuts at a couple of hundred miles and all was good. Now after 700-800 miles a couple of lug nuts were loose at all four corners. Anyone else have this problem with their over sized or after market wheels? This scared the crap out of me, the last thing I want is to experience losing a wheel at any speed.

Are you running front disc brakes? I have 338's on my '67 with '72 rotors. I just replaced the rotors and noticed right away the 338's will not seat on the hub unless you taper the end. I used a flapper on my angle grinder taper the ends. You don't have to take off too much.

[In The Ten Ring]

Originally Posted by davepl

Tangential to this discussion, but not worth a new thread: does anyone know where you can take a Craftsman torque wrench to be recalibrated? Sears doesn't do them in house (ie: you can't just take it to the store last I checked). I'm overdue!

I think you have to buy a new one. I asked that same question to the Craftsman tool guy at Sears (before it closed down) and he said there was a $50.00 charge for that and you sent it to the factory. That was about what answer the guy at the local garage that last did my inspection said.

I haven't had any more trouble since taking a wire wheel to both my hubs and insides of my alloy wheels. Next summer I hope to paint those hubs and get the alloy wheels powder or cerakoted.

[harpo231]

Just break it ,, then take to sears craftsman lifetime

[In The Ten Ring]

Originally Posted by harpo231

Just break it ,, then take to sears craftsman lifetime

The Craftsman we grew up with isn't the same one we have now. From what the clerk told me, the "lifetime warranty" did not include torque wrenches. If you can refute what that no-longer employed clerk said, I'd be happy to read it.

[71cheyennesuperlongb]

Just a question.Have you ever used anti-seeze on your lugs? The reason I ask is ,yes they will come off easier just not when you want.My best friend put his roadster together and we torqued the wheels on and went for a test ride. 20 miles later both front wheels worked loose to where a shimmy started.Stopped and checked and all 20 lug nuts were loose.I am not sure but I dont think you should even use light oil on the studs.

[dmjlambert]

I put the nuts on with no lube. It is good for this thread to come back up to the top. It's time for everybody to run out to the truck and check the torque on the lug nuts. I just found 1 loose.