loose lug nuts

[dlb]

last week, my wife noticed a CV-like clunking coming from the front driver side wheel of her truck. i took a look and noticed two of the lug nuts were gone. looked closer and saw that the two studs were sheered right off, and the other four nuts were loose. the last time i had the front wheels off was a year ago, and they've been fine since. the truck hasn't been taken off-road or hit any curbs or anything else hard or jarring so it seems odd that the nuts would have loosened off after a year of use. i'll be replacing the studs tomorrow.

anyone have any similar experience, or insight as to why the nuts might have come loose? the wheels are alloy, FYI. i read that differing steel/aluminum expansion rates can affect lug nut torque, but after a year?

[marlinh]

Normally after tires have been removed it is recommended to retorque them after 100 km. All tire shops will tell you to come back. That covers their butt for liability. Alloy wheels do tend to have lug nuts come loose. Has to do with their composition I guess. It never hurts to once a month check your lug nuts, lets say when you check tire pressures or before a trip. Just a safety precaution like checking your fluids. I've seen the odd vehicle stopped on the side of the road with the occupants hunting for their tire. Can't imagine the feeling that goes through ones mind when that happens. Never mind the risk of a severe accident.

[Petros]

I can find no reason for it but I have noticed that the lug nuts can work loose on alloy wheels, it has happened on several different vehicles. Once on our mazda MPV, made a funny (scary) sound but found they just needed to be snugged down. I wonder if it could happen when you install the wheels on a hot day, and as the season changes there is just enough thermal shrinking so they work loose in the fall? I have it happen on my Tercel as well. so I make a habit of checking them every so often, seldom do I find an issue, but when I have the lug wrench out for any reason I just walk around the car and give them a quick test.

[dlb]

very good. hence forth, i will check the lug nuts whenever i check tire pressures.

got the old studs knocked out yesterday and will pick up and install new ones today. the hub/rotor/bearing system in the front of her truck ('91 toyota 4x4, 22RE) is a PITA compared to the tercel front end. i think i've been tainted by learning to work on such a wonderfully bone-simple car.

[GLet71]

It's all in the torque, David. Whereas some of those dick tire shops still torque everything to 125lbs, your Tacoma is only meant to be 75lbs (if I remember correctly). Keep torquing it to 125, and you keep stretching the lug until finally they shear off. Call Toyota and ask what the specs are. For safety sake, replace all the lugs on your wife's truck and torque them up yourself. A mechanic friend of mine also thinks it is better to not put any lubricant on the studs prior to bolting the tire on, so I've been leaving the never seize up on the shelf for this application.

[Petros]

there is typically so much dust and corrosion around the lug nuts, even on alloys (electrolysis), I do not see how you could possibly get an accurate torque up. I use a corrosion inhibiting compound called "Corrosion-X", it provides very light lubrication but is not too slippery like anti-seize but it does keep the corrosion/electrolysis from forming between the nut and the alloy wheel.

[dlb]

funny, a few days later i pumped up the tire pressures and checked all the lugs on my corolla and westfalia, and found a loose lug on the westie! only one and not too loose, but nonetheless. crazy. live and learn.

replaced the studs on the truck and repacked my first bearing before i put it back in. that was really cool because i've heard lots about packing bearings but never done it. it was super easy, you just jam-pack it with grease! saw a few different techniques online, found one that worked well for me. i love a good learning experience. funny that a $4 repair could have had such disastrous consequences had we not caught it in time.