lug nut torque with mag wheels and steel nuts

Discussion in 'General Automotive Questions' started by Clark, Jul 14, 2018.

  1. Clark

    Clark In Maximum Overdrive

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    I have two Ford vehicles with OEM mag wheels using 60 degree nosed steel lug nuts - 2002 Ranger and 2012 Edge. The problem is the lug nuts feel squishy when I torque them to spec at 100 ft-lbf which is rather scary - as in will the threads strip out of one of these.

    The owner's manual says not to lubricate the threads which seems strange to me. My old engineering manuals say that torque specs are for oiled threads to insure the load is distributed over all the threads and I always did so with my Ranchero.

    I solved the problem with my Ranger when I bought a new set of lug nuts, oiled the threads, and wiped the 60 degree noses ever so lightly with anti-seize grease. Right or wrong, these torque up well.

    Now I rotated the tires on this Edge for the first time and it has the same problem. It did help to oil the threads and lightly grease the 60 degree nose on the lug nuts BUT one just does not want to torque up right. I did drive the Edge around a few miles and recheck the lug nut torque but this one is still scary. I have ordered a new set of lug nuts which may help.

    Still, I'd like to understand this. Anyone else find this problem with mag wheels using 60 degree nosed steel lug nuts?
     
  2. ribald1

    ribald1 In Maximum Overdrive PLATINUM MEMBER

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    Another reason to oil the treads is to prevent the nuts from seizing on the studs.
    Are you certain that the wheels use a tapered nose rather than a bell nose? If you put a tapered nose nut on one that requires the bell type and it will act just like you describe.
    It also can damage the wheel.
     
  3. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    As far as lug threads go, a couple things:
    1) Engineering allows for lube and non-lube (Remember, Dad was a Seabee and Civil Engineers Corps officer), but the torque must reflect that;
    2) On most Fords, the actual specification is 80-100, so if you lube the threads, 80 is the max torque, otherwise, 100 dry;
    3) A rep from Moog, with 35+ years experience, told me the only way he lubes lug threads is with lapping compound, which allows the nuts to torque down, but then 'sets,' like a very light duty thread locker.
    4) What John said about the type of lug nuts is very important. If these wheels are factory and you had to replace them for any reason, you should have got them from the stealership. Aftermarket, the tire place or wheel seller should know exactly what type you need with the wheels you buy.
     
  4. Clark

    Clark In Maximum Overdrive

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    No, Ford made these with a tapered conical nose, not a bell or flat shank seat. I tend to think the steel conical nose is seizing in the mag wheel material giving the squishy feel that never really wants to firmly seat - also why I think a light coating of anti-seize on the lug nut nose was helpful. Out of frustration I tried to sequentially torque these lug nuts at 50 ft-lbf and then 75 ft-lbf with the tires off the floor - which was fine. BUT then torquing to 100 ft-lbf with the tires on the concrete still left me with the one lug nut that simply does not want to seat correctly.

    These are OEM mag wheels with the original lug nuts.

    The replacement lug nuts are specific for these vehicles though not from Ford. They worked well with my Ranger.
     
  5. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    What works well with your Ranger, .ay not be the proper type for those wheels. I think I know which ones you're talking about. Is your torque wrench a beam or a clicker?
     
  6. Clark

    Clark In Maximum Overdrive

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    Snap-On clicker.

    Yes, these lug nuts are specific for these vehicles.

    Looking around the web there is a great deal of conversation on this very topic regarding oiled vs. dry lugs, alloy wheels, and recommended torque ranges.
     
  7. Basstrix

    Basstrix In Overdrive BRONZE MEMBER

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    Andy is correct with regard to lubed vs dry torque specs. In general, torque specs are considered dry unless otherwise noted. Lubing the threads will reduce friction enough to increase the preload on the fastener by 25%. This means that if the spec is 100 ft-lbf dry, you're pulling 25% more when lubed. This will load the studs and nuts to a level close to the elastic limit (beyond elastic results in permanent deformation) which is not good. 80 lbf would be the proper torque for a 1/2" lug that calls for 100 dry.

    For what it's worth, I also lube lug threads.

    Here's a simple online calculator: https://www.engineersedge.com/calculators/torque_calc.htm
     
  8. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    The biggest thing I learned from the Moog guy, was on torque wrenches, and this dovetails into the fastener loading aspect: use a beam torque wrench. Even an HF cheapie only has a maximum 1 lb-ft error, and in this case, you're not waiting on a click to happen (which, if the wrench malfunctions, can cause it to go beyond), but looking for when the pointer reaches the desired torque. I exclusively use a beam torque wrench for wheels, whether steel or cast.
     
  9. ribald1

    ribald1 In Maximum Overdrive PLATINUM MEMBER

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    Beam style wrenches require increased levels of torque to get the same reading with each use. All torque wrenches drift, the long spring types (click and dial) are least affected and can be calibrated. Beam style wrenches cannot be easily calibrated. Also parallax errors are a significant concern with beam wrenches.
    I generally use a beam type when running the torques up because it is fast. Then a quality wrench for the final torque.
     
  10. 1965 Ranchero 66G

    1965 Ranchero 66G In Maximum Overdrive PLATINUM MEMBER

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    I have three beam and a Snap On 1/2" drive click type, the clicker I've had for 25 + years and was last calibrated about a year ago.
     
  11. Clark

    Clark In Maximum Overdrive

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