Executive summary: the other day I checked my lug nuts, assuming that they would all be nice and tight just like they always have been over the course of many years, any time that I have ever gone to the trouble of checking my lug nuts. And I was gobsmacked to find that one of my lug nuts was loose enough that it could be turned using one’s fingers. Yes, as soon as I realized it was loose, I tightened it to the desired number of foot-pounds. But it sure was a good thing that I checked my lug nuts!
The main point of this blog article being, of course you should check your lug nuts.
Part of the background here is “all-weather tires”. When I was a teenager driving my first car, an old used Volkswagen, there was no such thing as “all-weather tires”. There were snow tires and there were regular tires and that was it.
There were the years I spent in Massachusetts attending law school and I did not have a car then. After that were the years I lived in Manhattan, and I did not have a car. I suppose it must have been during those years that tire companies devised what is (in my opinion) rather wishfully termed “all-weather tires”. As far as I can see, the term “all-weather tires” is more or less an oxymoron. Maybe there are places where you could live where the weather more or less stays the same all year, in which case no matter what kind of tires you have, they can count as “all-weather tires”. But if you live in a place where it is snowy in winter and it is not snowy in the summer, then I think it is completely unrealistic to imagine that any single type of tire could be well suited to all seasons.
Which brings me around to snow tires. When I was a teenager, the main thing about snow tires was that they were gnarly. It was the same general type of construction, the same general materials, but instead of a normal tread it was a very coarse and gnarly tread. Nowadays, the snow tires differ from the summer tires not only because they are gnarly, but they are also made of a different kind of rubber. The rubber in the snow tires has things mixed with it that are a bit gooey or a bit sticky, that are intended to help the tire grab the ice better.
Which brings me around to lug nuts. What happened with my most recent car is that I found it did not do as well in the snow as my previous car. I had sort of been in denial for some years, trying to avoid facing the fact that all-weather tires are not really “all-weather”. And finally, this past winter, with my most recent car, I reached a point where I realized there was just no choice about it. I needed to suck it up and get snow tires.
What I did was order up a set of snow tires and wheels from Tirerack.com. The idea was that the vendor would mount and balance the tires on the wheels, and ship them to me. This worked out very well. This was some months ago, during winter.
Where I live in the mountains, it takes a long time for spring to arrive, and it means that the day for swapping summer tires for snow tires comes a lot later in the calendar year compared with that day for lower elevations and warmer latitudes. So it is only rather recently that I swapped my summer tires for my snow tires.
The important thing here is my sister Ruth (web site) had gone to the trouble to remind me that after driving around a bit on the summer tires, I should check to make sure my lug nuts are tight. Had she not reminded me of this, I must admit I might not have thought to check. And what happened is, sure enough, one of them was loose. It was so loose that I was able to turn it with my fingers.
I immediately torqued it to the desired 129 foot-pounds.
There is one more potentially interesting thing to see in the photograph above. I had not really paid attention until now, but this wheel has a number of lug nuts that does not match the number of spokes. With many car and truck wheels the number of lug nuts matches the number of spokes. Or one number is double the other number. But with this wheel, the number of spokes is seven (a prime number) and the number of lug nuts is five (also a prime number). The two numbers are not the same, and neither number is a multiple of the other number. I think this is quite out of the ordinary.
On your car, does the number of spokes match the number of lug nuts?
Have you ever, when doing a double-check of the tightness of your lug nuts, found one to be loose?
Please post a comment below.
Years ago, I was driving on the 405 from LA to SD and I noticed that the right rear wheel of the car in front of me looked a little wobbly… it was hardly noticeable but I listened to the little voice in my head that told me to get out from behind this disaster waiting to happen. So, I sped up, changed lanes and passed the car.
Not a minute later I glanced in my rear view and saw the wheel come off the car, the car swerved and hit another car… the wheel that came off bounced and hit another car in the windshield which caused that driver to lose it and swerve into another car. It had to have been at least a 5-6 car crash… perhaps because of loose lug nuts.
When I’m not working I’m racing my BMW wheel-to-wheel at tracks around the country. My life depends on tight lug nuts. We tighten them at the beginning of the day when the wheel is cold; if the wheel studs are hot we use a lower torque value to account for the heat expansion of the bolts.
It’s important to tell a tire shop what the specific torque value is for your wheel bolts because they often over-tighten them, damaging the bolts.
Thank you Flann for posting. Readers, you can see Flann’s race car here where she explains:
When I was a teenager my way of tightening lug bolts was to lean on the lug wrench until it felt like “enough”. I never used a torque wrench and I am pretty sure I never knew the “correct” torque for lug bolts on that old 1966 VW bug. Fortunately for me, I guess I somehow avoided damaging the lug bolts or the brake drums into which they were screwed.
Last autumn was when I received my snow tires (which had been previously mounted and balanced) from Tirerack. I selected the option of getting them shipped to a nearby tire shop to get the “all weather” (yeah, right) tires swapped out for the new snow tires. It never crossed my mind to find out the correct torque to use when mounting the new wheels on the car (the answer turns out to be 129 foot-pounds) nor did it cross my mind to communicate such information to the tire shop. I guess I sort of assumed they must already know the correct number for each car or for each type of wheel. Or I sort of assumed maybe there is some more or less standard number of foot-pounds that always gets used. Or maybe there was one standard number to use if the wheels are steel and another standard number to use if the wheels are mags. But I can see from your posting that you try to be smart about this stuff.
There is a technique to torquing studs (race car) and bolts (street car) as well, to to avoid bending the studs/bolts. One stands with the hip against the side of the car and elbows resting on the thighs for stability, then pushes downwards on the wrench handle such that the motion is perfectly vertical with absolutely no lateral deviation. The lug nut wrench extension has to be the correct length because if it’s too short and the handle hits the side of the car, the motion by definition will incur a lateral force. The details do make a difference.
Sometimes the nuts are too tight so we have this now:
https://www.milwaukeetool.com/Products/Power-Tools/Fastening/Impact-Wrenches/2863-20
So this tool is powered by rechargeable batteries. And you can configure it with your smart phone. I imagine this means you can set the number of foot-pounds of torque through the smart phone.
Yes it has settings for the torque, but it just allows ranges for each setting. You can’t dial a specific #