The Stovebolt Site Forums The Shop Area General Truck Talk Lug Nut Torque

Once upon a time, when you bought new tires, the guy that put them on used a lug wrench. Now it's an impact wrench, followed by a torque wrench. I have a '64 K10 'Burb that is getting new wheels and tires today. Anyone know the correct pounds of torque for a '64 K10?

Just use a lug wrench and say click when you think they are tight.

Yeah the old elbow torque wrench, works well. If ya gotta be precise, 45-65 ft-lbs according to the 63 shop manual for a C10. Brian

Here are just a few, Google “lug nut torque”

http://www.tirerack.com/wheels/tech/techpage.jsp?techid=107
http://www.gglotus.org/ggtech/wheel-stud/lugtorque.htm
http://www.stockcarracing.com/howto/scrp_0504_proper_lug_nut_torque_specs/

Denny Graham
Sandwich, IL

Brian and Denny,

Thanks for the info. I'm getting 7" wide alloy wheels and 9.5 X 30" tires mounted on the wheels. The guy at the tire store wants to torgue them to 85-90 lbs. But, according to the websites that Denny provided, the proper torque for a 7/16" lug is 50-60 lbs. Would the increased weight of the larger tires warrant the increase of torque to 85 lbs. ? Could the increased torque cause the lugs to fail? Or am I making a mountain out of a molehill? I one of those guys that sweats over details.

7/16 studs will handle up to around 80 without any trouble. That's the spec for the later Chevy 4x4 with that size studs. However, I would go closer to what the shop manual says, no more than 75. Make sure to request that the do not hammer the nuts on with an impact. Running them up is OK, with maybe just a tick past seating the nut, then hand torque them to final spec, going around the pattern at least 3 times.
If you have your own torque wrench, recheck the nuts after you put about 25 miles or so on them. You would be surprized at how loose thay can get once the weels seat in to the hub.

An old mechanic friend of mine use to say when asked how many pounds of torque he put on a bolt, 185 pounds of S**t on a 30 inch bar.

Torque is specified for a specific thread size not to exceed the yield point of the material. Obviously different materials will yield at different points of stress so the torque for a hardware store bolt will be different than the torque for a grade 8 bolt. Lug bolts are generally made from alloys that are similar in strength; therefore we can use a common torque value on them. At the low side of the spec the material begins to stretch thus creating tension to keep the nut from coming loose, at the high side of the spec is the maximum that the material can be stretched before it begins to yield. If you exceed the spec it's a good bet that you have stretched the thread beyond its yield point.

That's the way I view it, now I'm open to hear
"The guy at the tire stores reason is why he wants to torque them to 85-90 lbs. And your mechanics explanation for using 185lbs of what ever on a three foot bar to torque a lug nut.

Denny Graham
Sandwich, IL

This would be the part I'd worry about. Never had a problem before...but just last week I found that the 'whooop whooop whooop' noise while test driving was the front left. They were finger loose.

I have always checked before...and here's the one example to prove my rule!

Been there, done that. After I got home and had a look, I used my dad's four-way lugnut wrench to tighten them down. I think I was 16 or 17 at the time.

I now use a 18" long 1/2" drive Craftsman breaker bar to torque lugnuts down. I stop leaning on it when the nut stops turning. No more flapping wheels.

Rechecking is especially important with aluminum wheels. The alloy they use actually shrinks a little when it gets hot. We have a shop policy to have customers return after 25 miles to have the nuts retorqued. If you read the little manual that comes with aftermarket wheels (if the shop actually gives it to you) it states that very thing in the torqing directions. There's usually a torque guid with rough torque ranges to use for assorted thread sizes if the vehicle factory spec isn't available.

Wow, let me jump in on this one. My pet peeve is the shops here run them so tight that King Kong himself would have a problem. I've twisted many GOOD 4 way lug wrenches loosening them as soon as I get home. Some shops run them up so tight there is no need to torque them but they put that little ole torque wrench on there knowing good and well it will click. Why not when they run 175PSI on the guns. First I know there is good reason to re-torque aluminum and other wheels but for plain steel wheels, regular cars and pickups, I have used 90PSI on lug nuts for well over 25 years and never had one to come loose. I also found that at that torque my youngest daughter can get them loose if she has to be the one to change a tire. I do NOT know what 90 PSI is in torque lbs but it works for me. Now, lets hear why this isn't suppose to work :p but does!!

Just my opinion from experience being a mechanic who works in a tire shop, is this..

Its not so much the exact torque that counts, as long as it is not far from specs. A 7/16 wheel stud can handle up to 80 lbs but its not reccomended as this will stretch the stud and will cause eventual failure. Hondas use 10 and 12 mm wheel bolts and use 70-80lbs torque effectively.

the big concern is torquing EVENLY across the rim.
Even most tire shops will gun on a rim and then set the torque wrench to 80lbs. Then as in the previous post, puts it on to hear it "click".
If the lug nut does NOT turn with the wrench before you hear the click, all you know for sure is that there is AT LEAST 80lbs on the nut.
one could be at 90lbs, one at 80, one at 120 and so on.

What can happen from un-even torque..the lug with the most torque takes the load of the vehicle!!
untill it is stretched and evened out with the next tightest lug. so on and so forth. If there is too large of a torque difference, the tightest lug WILL break. I have seen this before and again and again. Uneven torque will also cause warped brake rotors. Usually not right away, it takes a little time and a few good stops to warp them. This is a possibility. It has happened to me. try this, take off a wheel, put the lugs back on to hold the rotor to the hub and set up a dial guage on the face of the rotor. torque the nuts, spin the rotor and take a run-out reading. loosen off one or two nuts and try again. you will be surprised. 10 lbs difference can cause .oo3" run out. (which is max tolerance for most manufacturers).

There are a few more reasons for even torquing but
I feel these are the most important. It is possible to use a gun or lug wrench and never have a problem. I used to and didnt have trouble, but now I tourque everything and still dont have a problem

I use the OLD standard german torque specs----
Gud 'n Tite

tire shops tell me 75 to 80 foot lbs.

on my 85 Chevy c10 i just use my impact and reg. impact socket and just gun em on till the socket quits turning (my impact is rated for 380 ft lbs at 100 psi i think), dad said the one time "how tight you put them on cause i couldn't get em loose, how'd you expect to change it if ya gota a flat?"
Nate

It's worth rereading James.h's. contribution! He has touched on the essence of using the proper torque. Throw in alloy wheels to the mix and just "crankin'em down" just doesn't cover all the bases.

Avoiding a lost wheel is just part of the equation. You wouldn't think of throwing the torque to a head bolt without following a sequence and insuring that everything was by the book. I personally think that the same care should be exercised on properly installing a wheel. Doing it correctly the first time is going to pay off in the long run. "Drive on"

Dave

I agree with James H. Many of todays smaller cars seem to be prone to warped rotors because of their smaller mass. I never go to a tire shop without expressing that the lugnuts are put on and torqued by hand.

Many tire shops employ unseasoned kids that just don't pay attention or have little or no experience. For the lugnut torque issue alone, I remove my own rims and let them replace the tires and balance, and only because of the lack of equipment. I then bring them home and put them on myself.

Are you willing to bet your life on the skill level of some mouth-breather with an impact wrench? All my auto mechanics students get the "torque every wheel nut" lesson drilled into their heads from day one in the shop. No, a lot of torque is NOT better. I hope I'm somewhere else on the road when the wheels start coming off the "just crank 'em down" guy's car due to broken lug bolts!

If a spec. isn't available, some rules of thumb should apply:
7/16" lug bolts- - - -65-70 ft./lb.
1/2"/12MM lug bolts- - - -85-100 ft./lb.
9/16" lug bolts- - - -110-125 ft./lb.
5/8"/16MM lug bolts- - - -125-140 ft./lb.

Going noticeably over these numbers risks bolt stretch and breakage. Much below those numbers will risk loose lug nuts after driving a while.
Jerry

I made a good living at the Nissan/Isuzu place-Sears & PepBoys were right up the street, we regularly got Troopers, Rodeos, even a few Pathfinders on a hook needing studs, nuts, & sometimes even hubs or axles! It was funny to see a truck come in w/brand new tires all leanin because the lug nuts are busted.

hotrod lincoln's torque numbers are bang on.
and another tidder of information per my last post...the .003" run out induced into a rotor was on the front of a 1998 ford f250. so not just hondas are suceptable to this.

I just had a wheel loosen on me, and that's the first time in over 40 years of driving. I had put the lugnuts on with a four way wrench, and I tightened them down to where I could still get them off if I had a flat. this is also the first time I've had aluminum wheels. The wheel on the other side was cranked down by a repair shop in Virginia while I was on a trip in April. I have wrecked a four way wrench, and bent a breaker bar trying to get those lugnuts off. They're on there until I get new tires, I guess. Then it's the tire shop's problem.

15 years working in parts and service departments at new car dealerships taught me a lot. I would NEVER tighten lug nuts without a torque wrench.

Now, let me see here, did the lug wrenches that came with any auto have a torque built in? Humm, did anyone know what the torque should be on a lug nut?

You got to watch those muffler and brake shops, too. Most of those places will ram the nuts on as tight as they'll go. I've had to replace many nuts/studs and even a few wheels because of that. James H and Hotrod Lincoln hit the nail on the head with how to properly torque lug nuts. I do prefer to get the manufacturers specs for torquing, but Hotrod Lincoln's spec list is perfect if you don't have acess to the specs. You would be surprized at just how high some newer vehicles actually torque to. Take the '98 and up Silverado for example. They torque to 140. Dodge Ram-135. And the f150-150. I just had an E250 in yesterday that torques to 170! Most passenger cars are right around the 100 ft/lbs mark, depending on make. GM is 100, most Chryslers are about 85-115, fords 87-105. Asian cars run anywhere from 75 (Toyota) to 87 (mazda) average.
We use those torque limiting extensions in our shop, and if used correctly, they do work. Of course we do recheck after anyway to be certain it's right. I personally use a digital torque wrench (Snap-On) that gives the actual reading, instead of just "clicking".
BTW-I work at a Sears, and have never broken a stud when installing a wheel. I have broken them taking them off, always after they had been serviced at one of the local brake shops or Wally World. And a few time when the Dealer had servived it, to.

I think for the most part if we use good common sense we will be OK even though not "by the numbers". I will say that this is a very interesting subject and sure a lot has been learned. I delivered parts for local parts house for over a year and some of you would be surprised how many new lug nuts/studs that I delivered to a LOT of shops BUT there were two shops that went through them like X-lax through superman. I had to give a young fellow a shout when I saw him run the very first lug nut up in one shot while putting a new set of tires on my truck. I think he actually listen after I told him I was still on the lead lap and no hurry.

On our way to the airport and running a little late for our flight to Mexico we had the left front time fall off. This was a few days after having the local Firestone store replace all four tires. We managed to get a tow truck to pick up the car and deliver us on the the airport a few minutes before the flight took off. Man that was a mountian of stress.
Since then I recheck those lugs nuts anytime they have been messed with.