Wheels' Lug nuts loosened unexpectedly

Retired VIP wrote in news: snipped-for-privacy@4ax.com:

One thing I'd caution is to make sure the nuts are properly mated to the wheel. When people start swapping and mix-matching OEM for/with aftermarket, some odd and non-functional combinations can occur. Not saying Built_Well is doing this, but just in case...

A case in point is a neighbor of mine who obtained a set of wheels and a set of chrome nuts from separate sources. Well. The wheels had a

45-degree shoulder on the nut seating surfaces, but his new wheel nuts had what appeared to be a 60-degree seating surface.

My neighbor came to me saying the wheels kept loosening up on him, and what could I do to fix it? I made some basic checks, found the mismatch and said he should get the proper nuts, even if they were cheapo non-chrome ones. He insisted he had no time and had to get where he was going, so I tried to torque them up for him. Believe it or not, they did eventually reach proper torque, but it was obvious the wheel hole shoulders were deforming in order to achieve this. I told him I wasn't sure how well this was going to work, so to be careful as he drove.

They came loose again in about an hour's driving.

Given your comment below, I wonder if there was too much load on the front wheels.

Typically the lugs need to be pattern torqued > 60 lb/ft before loads can be placed. But IMO it's more desirable not to lower them. So I don't even lower them, just tighten them to spec like you do with the rears. Inspect again while raised. No problems.

Now instead of lowering the front try a block of 4x4 (you can get $1 scraps at home depot) or $4.99 Amazon tire chocks.

Since the front wheels moved

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JohnGdole, that's an excellent idea. Instead of lowering the front wheels until they just barely touch the ground enough to prevent their moving (like Tegger and I do), you're suggesting to lower the front wheels until they're still an inch or so above the ground and then slip a 4x4 piece of wood or a tire chock in the one-inch gap between wheel and ground.

I'll try that next time. If I'm picturing things right, you're saying the tire chock or wood jammed into the one-inch gap will prevent the front wheels from moving while you're torquing them?

Sounds like a great idea. Did you read this somewhere, and if so, where? I'd like to read it myself, or at least know what the source is, if you can remember.

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By the way, the author of the book "Auto Upkeep" also torques his wheels while they're just barely touching the ground--touching just enough to prevent wheel movement.

However, the author neglected to mention not to torque your wheels while they're hot. Luckily, I read at TireRack.com the following:

"When rechecking torque value, wait for the wheels to cool to ambient temperature (never torque a hot wheel)." [Sounds like a good idea. But does anyone know why?]

Here's a longer passage from TireRack.com :

"When installing new wheels you should re-torque the wheel lugs after driving the first 50 to 100 miles in case the clamping loads have changed following the initial installation. This is necessary due to the possibility of metal compression/elongation or thermal stresses affecting the wheels as they are breaking in, as well as to verify the accuracy of the original installation. When rechecking torque value, wait for the wheels to cool to ambient temperature (never torque a hot wheel). Loosen and retighten to value, in sequence. Simply repeat the same torque procedure listed above."

Holey memory. I correct myself in that I LOOSEN lugs while the tires are PARTLY raised (not fully on the ground because the lug nuts are slightly more difficult to remove). I INSTALL lug nuts using tire chocks/4x4 wood block to full spec (25/50/76 lb/ft steps), without the tire touching the ground to prevent that slight tilting. Why?

I stopped even with the partial weight of the vehicle on the ground after I noticed a nut or two would still turn very slightly with the full weight on the ground when they didn't off the ground. Which means uneven torque was not introduced.

IIRC, Costco hand torque off the ground but the last check always by the supervisor I think they had the tires *partially* on the ground, couldn't remember for sure. This would be fine because even with heavy vehicles like RVs you can torque on the ground them after achieving 60 lb/ft:

That's what worked for me.

Gosh you'd think this was the space shuttle. I use a small 4 way lug wrench and calibrated elbow, when my elbow clicks it's good enough and thus far warped rotors have never been a problem. Now I did have a neighbor that managed to twist off a lug bolt on his honda, and to compensate for that he tightened the other three, and twisted another off, and I don't remember if he twisted a third off or not but I wound up helping him replace the lug bolts on that wheel. And if you ever get an old mazda pickup and some old buicks and probably a few other makes and models some of the threads are reversed side to side. And I had a 280Z with only three lug bolts on one of the front wheels. I drove it that way four or five years until they finally caught it on the annual safety check. Never warped the rotor on that wheel either. I almost always put a little grease or oil on the threads and nut and if it's an alloy wheel always the back of the wheel or surface it rests against.

Heh. You stole my method.

--Vic

I haven't seen rust or aluminum corrosion cause wheel nut loosening either. I have seen wheel nuts become very difficult to remove due to rust or corrosion.

The reason I asked whether the wheel are alloy or steel is that the recommended torque is different for alloy and steel wheels.

A local place did mine for about $40.

I was informed new torque wrenches can be off by 15%.

FWIW, I've owned a lot of cars, and have had two cars that were absolute sticklers and PITA's for loose lug nuts. Most of them you could do wheel nuts by feel and never worry, but my Jimmy and my old old Buick if you didn't torque 'em proper and then recheck the next day, the SOB's would work loose.

You might have one of "THOSE" cars where every time you take the wheels off you'll have to check the torque a couple of times.

Ray

Easily. I bought two US-made Husky torque wrenches and the calibrating guys had to work on them for some time to get them anywhere near accurate. Cost more than the wrenches. And that's for good wrenches, not the cheap stuff found in some places now. Sears here in Canada sells Chinese-made tools, has been for a long time, while Sears in the US might still be selling better US-made wrenches. Dunno. Cheap wrenches, at any rate, could be 30% off and have very poor repeatability, giving a different torque every time the wrench is set to zero and then back to the desired setting.

Dan

If this is true, and I have no reason to doubt it, using a torque wrench would be about as accurate as using the click in my arthritic elbow.

Does anyone know who makes good torque wrenches that give consistent results?

Jack

The expensive ones they used on my day job are from Norbar in the UK. They get an annual calibration anyway, though. We also have some cheaper ones that came from Aircraft Spruce and Specialty.

--scott

I am of the opinion that the beam type wrenches are inherently accurate. They are unfortunately inconvenient to use. What I have done in the past was to use a beam type wrench to check my click type wrench. Maybe a fools idea, but so far, nothing has fallen off. And actually it should relatively easy to check any torque wrench with weight applied at the handle by a string. Never tried it though.

Ed

I believe I have seen setups where deadweights are used to calibrate the torque wrench. This is what I would use, if I were going to calibrate one, since an accurate deadweight is a reproducible standard.

For a lot of applications, extreme accuracy of the torque wrench may not be totally necessary, if the evenness of adjustment of the clamping force is more important than the absolute magnitude of the force.

Still, most of us would not want to pay money -any money - for what is supposed to be a precision tool, only to get something that is embarassingly imprecise.

Maybe we could get some car magazine (or even Consumer Reports) to do a series on this?

Most torque wrenches are within 2-4%. But the important thing is more of even torque. If clicking elbows can achieve that and be reasonably close to spec torque then you'll be fine ;) ;) ;)

Yeah, don't torque with load on the wheels, at least before reaching

60 lb/ft. That puts "side-loads" on them. Better yet, avoid even partial loads until reaching 60 lb/ft.