So it’s my first time changing wheels. My logical sense tells me the wheels spin like hundreds or maybe thousands of round per minute when going on highway so i better screw the wheels damn tightly. But then i am concerned that too tight may damage/wear the nuts and bolts. So how do I secure the wheels just right? Thanks
The torque specs for the lug nuts depends on the vehicle.
You should follow the torque specs in your user manual. Typically most cars run around 80 to 100 ft-lbs of torque on a dry stud but you should really make sure you have the correct number for your vehicle and a decent quality torque wrench to ensure that you get it right.
I also recommend re-torquing the lugs after about 200 miles of driving, especially on alloy wheels.
If you are using the lug wrench that came with your car, it is difficult to over tighten your wheels with that. If you are using an after market lug wrench like a 4-way, then you can overdo it. Same if you are using a long breaker bar and socket, and especially if you are using an impact wrench.
In many/most tire shops, you will see an air powered impact wrench being used. These commonly use an extension called a torque stick though many of us question the accuracy of them, but they usually don’t allow the wheel nut to be overtorqued to the point of doing any damage.
The best way is to use a torque wrench and the torque specs provided by your manufacturer. But if you use a torque wrench, especially a click type, but same for all, it is only accurate when it is moving. Once you stop turning the nut, it takes a lot more torque to restart the nut turning. So to be accurate, you apply force until the desired torque is met and stop.
My advice is to initially torque to about 25 ft lbs, which is about hand tight with a small ratchet or holding the supplied lug wrench near the head and twisting with one hand. The arc from 25 to the specified setting, usually 75 to 110 ft lbs is about 90 degrees. Then set the torque wrench to the desired setting and with the handle pointed at about the 12 o’clock position, tighten to the click in a smooth motion that should take about 2 seconds. It will be dead on at that point. Stop immediately at the click and try to avoid adding any “bump torque”.
If you are changing a flat out in the middle of nowhere, use the factory supplied lug wrench. Tighten to the initial torque as I specified above. Then add about 90-100 degrees rotation from that and it will be close enough to get you to a repair center.
There is a torque spec for wheel lug nuts and it may vary between steel wheels and alloys. I have seen situations where over tightening has caused brake warping on vehicle that have had their lug nuts over tightened. If using a temporary spare (assuming it’s steel (haven’t seen any other types)), tighten as much as possible with your lug wrench. Avoid placing added leverage by using a pipe or extension. Replace it ASAP and torque to spec.
Working in a star pattern for this step and all following steps, turn each nut until it just starts to snug up. Go around again and make each nut fairly tight but not too close to the final torque. If the car is on a jack, let it down now because of the amount of force you’ll apply in the next step. Using a torque wrench, smoothly torque each nut to the correct value. Make a note to retorque the nuts after driving 100 miles or so. Remember to set your torque wrench to the lowest setting before storing it.
By the way, when taking the wheel off, make sure you break the nuts before jacking up the car because you might need to apply even more force in this case. Also, don’t ever use a torque wrench to break the nuts.
I have no affiliation with them, but they do provide this online chart
You’re smart to ask about this. Over tightening lug nuts can cause damage to the studs to where they cannot be properly seated again and can even break them off.
IMHO Keith has given you excellent guidance. A “click stop” type torque wrench can be bought very inexpensively. Here’s one source. Click on the individual wrench to see its range. My lugs are specced at 78 ft-lbs, you’ll need to get your spec from your owner’s manual or, if you don’t have one, the dealer parts window guy. Ask nicely and he’ll be happy to look them up.
I keep a preset torque wrench in my trunk with a deep socket of the right size already installed, because flats always happen to me on dark rainy nights and I don’t want to try to find the right spec and set the wrench under those conditions. You don’t need anywhere near the accuracy you would if you were rebuilding an engine, so the calibration from the factory is fine.
Enjoy. And keep asking questions. The smartest people in any room are always the ones asking the questions. Bank on it.
Even though I haven’t had a flat in…years…one never knows when that situation might take place.
Yes, I do have free road service through my car insurance, but I insist that my lug nuts be torqued to the mfr’s specification, and as a result I keep my pre-set torque wrench in the under-floor section of my cargo area at all times.
As posted above, it varies car to car. Most of the Chilton/Haynes repair manuals have this spec, or if you visit a dealership when they aren’t busy they’ll probably look it up for you. Once you got the spec, you can do some quick math to figure out how much force you need to tighten them. Say it is 80 foot pounds. That means you need 80 pounds of force on a 1 foot wrench or 40 pounds on a 2 foot long wrench. Say you have a 2 foot long breaker bar and corresponding socket. That’s what I use for tightening wheel lug nuts. You need to apply 40 pounds of force then. So take your bathroom scales out there and press on it until it reads 40 pounds. Now use that same force for the final tightening. You’ll be pretty close doing it that way. After you’ve done it a few times you get the knack and can just do it by feel.
BTW, when installing a wheel and tightening the lug nuts, make sure the wheel is completely off the ground at the start. To prevent any binding or tilting. Then loosely tighten the top lug nut, then the two next to it, again loosely, making sure the cone shape indented in the wheel are meeting up with the cones on the lug nuts. This is important, otherwise the wheel will be off center and won’t roll smoothly. Then loosely tighten the rest, then gradually tighten them is a cross-pattern, first to 1/3 the spec, then to 2/3 the spec, then to the full spec. That’s how I do it anyway, and seems to work for me. I put a thin amount of moly-lube on the threads [to help in removing the lug nuts next time], but not everyone here agrees w/that.
I was always told you should back the torque setting back to zero after use to prevent the spring from getting “set” And ruining accuracy. But then again with wheel lugs being within a couple ft/lbs, but uniform is probably sufficient.
What scenario is changing “wheels”? Flat tire? Swapping 4 rims? Steel? Aluminum?
The OP shouldn’t do this. Otherwise the nuts will be overtorqued.
If this is an issue, then break and retorque the nuts every month or two. That takes five minutes.
Torque values on lug nuts aren’t critical enough for me to justify having to try on a dark & rainy night to reset the torque value on the wrench before torqueing the lug nuts, which I’d have to do if I zeroed the wrench after every use. I’d rather have it preset. Heck, the manufacturers don’t even provide a decent tool to set lug nut torque values. You’d think they’d at least provide those spring steel torque-sensitive ratchet extensions that “let go” when they hit their preset level (my brain cannot retrieve the common name for them at the moment).
Edit: I think they’re called “torque sticks?”
Thats 20 pounds on a 2’ long wrench. Torque increases by the square of the distance.
Sorry, wrong. It’s force in pounds multiplied by distance from the rotation center in feet, gives you foot-pounds.
Technically, torque is a vector.
Maybe you guys are right. I know that I was taught different, that calculating the actual torque involved squares. I don’t remember the actual formula whether it was something like Ta=Tm(A2+B2/A2) or Ta=Tm(A+B)2/A2 where Ta is actual torque, Tm is measured torque, A is the length of the torque wrench and B is the length of the extension and 2 is squared. I can’t do superscripts.
I just can’t find anything to support that right now. But doubling the length of the vector seems to make tightening feel like 4 times easier.
Although I have never torqued a lug nut and prefer to just use the stubby wrench that comes with the car to do the final tightening, I just might have to buy some of these-
Why don’t they list the values of the various colors?? Or did I miss it…
Yup. Ain’t no squares in this equation!
Trying to remember my physics. You may be thinking of rotational inertia. Like the pendulum on a clock, its inertia is m * r ^2 . m being the mass of the bob on the end of the stick, and r the distance from the clock to the bob. For something like a wheel where most of the weight is at the circumference, I think this means the rotational energy is proportional to the square of the radius of the wheel.