It seems plausible to suspect sabatage, but there are other possible causes: The wheel, nuts applied backward (upside-down), acorn nuts, and improper nuts.

The holes in the wheel could be worn out. Note that the holes in the wheel have cone shaped shoulders to match the cone shaped nose of the lug nuts. What is supposed to happen on tightening is the nut contacts the wheel before the nut the nut goes all the way down to end of thread or contact with the lug plate. Upon further tightening, the wheel flexes a bit (acting like a big, stiff spring washer, and the nut should go tight before the nose of the nut contacts the back plate or runs out of threads. What can happen is that someone gets too agressive with the impact wrench and stretches the metal around the holes in the wheels, especially when the hardness and strenght of the wheel is much less than that of the nut. Thereafter, the wheel can not be properly tightened because the nut runs out of thread or bottoms out before becoming tight enough against the cone shaped hole in the wheel. If these were used wheels purchased to dress up the vehicle, those may have had worn out holes, or had been flattened such that no spring action remained.

Lug nuts have a tapered nose on one end. If these are the common variety of lug nuts with threads all the way through, the other end of the nut is flat. It is possible to put these on backward with the flat side toward the wheel, thus negating the locking feature. Nuts so applied are in danger of loosening. The tapered end of the nut goes against the tapered shoulder of the hole in the wheel.

A third potential problem comes with acorn nuts, the type that has a closed end. These look great, but these must fit the wheel and lug combination. The nut must tighten againt the shoulder of the tapered hole before running out of threads.

It is obvious by now that a common machine nut is a mis-application. If the nuts are flat on both sides, these are totally wrong.

Back in the 'good ole days' it was thought that loosing a lug nut was more common on left wheels than the right when all nuts and studs used right-hand threads. This harks all the way back to horse drawn wagons and buggies where the wheels were held on with a single, large, square nuts. These nuts were not put on very tight, some not much more than hand tight. The nuts on the left side had left hand threads and the right side had right hand nuts. Forward motion of the wagon or buggy tended to tighten the nuts when the wheel thrust against a nut. All went well so long as the motion was always forward. It was possible to back a nut off if a wagon was moved backward for several rotations of the wheel, but this seldom happened with experienced wagoneers since they were aware of the problem. The driver did not want the nuts to be too tight because periodically, he needed to grease the simple axle bearing. To do this, he backed the nut almost all the way off, yanked the wheel outward to expose part of the spindle, apply a dollop of grease, pushed the wheel back and snugged the nut. If the nut was too tight, the driver might not be able to loosen the nut with the rudimentary wrench carried on the wagon.

So much for history. Many cars up into the 1950s had left hand threads on lug nuts and studs. Usually, the stud had the letter "L" stamped on the end of the stud. Most "grease monkeys" and "flat fixers" knew to look for the left-hand mark before applying the impact wrench. (Flats were common with inner tubes.) But in my lifetime, I did spot a couple of novices who did not know or understand about left hand threads. These guys would attempt to remove lug nuts with the air wrench set for L-H rotation, and when nothing moved, they'd jack up the torque until somehthing did move.

Thanks Jemdandy. I'll have DH read this and see if the backwards issue or the worn wheels apply.

**I'm curious what you think. Sabotage or very bad luck? Thanks.**

Could be either. Unless you guys p*ssed off some low life somehow, I'd lean towards bad luck or misapplication as the other poster suggests. I don't think garden variety vandals typically do this kind of thing to one vehicle multiple times. jmo

If you had said, "my husband had his brakes inspected" or "tire rotated", or "wheels balanced", I would have said, "Ah ha! We have a prime suspect. Someone put the nuts on finger tight or merely snug, got distracted and forgot to finish the tightening job" But no, you said that he had no such work done.

Here's another possibility. He had on pretty, dress-up lug nuts and someone stole those, replacing them with regular, mundane nuts, anything that would fit. They did not need a jack to steal the nuts - merely remove one nut at a time and replace with any old nut as you go around the wheel. If all replacemets were lug nuts, they might be a mix of styles. However, I'd suspect that hubby would notice the change right away, but then, maybe not because at this time of the year, we go to work and return in near darkness.

In just about every owners manual, you will find instructions that advise the owner to re-torque the wheels 50, to 100 miles after they have been removed for servicing. There is also normally wording that advises re-torquing the wheels at 1000 mile increments. Now sure, NO-ONE does this, because everyone expects wheel nuts to always remain tight. One of the most common causes of a wheel loosening up is corrosion that occurs between the wheel, and the axle hub. A tech that is concentrating on his/her work will clean this corrosion off, or at least notice the wheel resist tightening normally, as it will bind a bit, and put a torque load the nuts for too long of a distance. Picture a nut as a lever. As you apply pressure to the lever it moves easily right up to the point that it makes full contact with what you are trying to move. From that point, the effort you have to put into moving the lever will increase very quickly. A nut or bolt when being tightened works the same way. There is a specific distance that the nut should turn from the moment it makes full contact until its fastening torque is reached. If that distance is too great, then something had to cause a false "full contact", and that could be corrosion. Now allow for sufficient shocking of the assembly that breaks the corrosion allowing the wheel to settle and suddenly you have lug nuts that were tightened completely at one time, but now are too loose to hold themselves. I used corrosion here because it is quite common, and also because it's the easiest cause to explain. There are other causes, in fact there are too many for me to try and type out. In all but the most bizarre cases, re-torquing the wheels as directed in your owners manual solves the problem.

Oh, and don't rely on that cheap tool every car comes with, get a real torque wrench and socket. Plus purchase an inexpensive socket and breaker bar too keep in your car for wheel service.

This morning, I'll be servicing my flat bed tow truck. One of the REQUIRED steps is to re-torque the wheel nuts. The torque spec on this puppy is 400ft/lbs. By the book, I had to do this at 1000 miles. That means one at a time, break them loose, and re-tighten them. You have to have the correct tool to do that, even then it's a big time work out. This truck has 32 lug nuts total......

sounds like someone might have been attempting to steal the wheels, and got scared off, b-4 the job was done.