Lug Nut Torque Spec on Aftermarket Wheels?

[Hack]

Ford's engineers actually know what they are talking about with this spec. It's not that tough of a calculation to perform. I would also advise against trying to hit the low end of the tolerance. There can be a big variation in friction depending on how clean the threads are, and if a fastener is undertightened it can come loose. That's why people measure fastener stretch in rod bolts in high end applications. Measuring the actual amount of stretch of the fastener is more accurate than the torque reading.

My dad had a rim come off his '72 el camino at one time. It wasn't pretty.

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[Stuntman]

No, he's right and you're wrong. The proper torque is 150ft-lbs per the owners manual.

Read the thread.

 

[Tomster]

Ford's engineers actually know what they are talking about with this spec. It's not that tough of a calculation to perform. I would also advise against trying to hit the low end of the tolerance. There can be a big variation in friction depending on how clean the threads are, and if a fastener is undertightened it can come loose. That's why people measure fastener stretch in rod bolts in high end applications. Measuring the actual amount of stretch of the fastener is more accurate than the torque reading.

My dad had a rim come off his '72 el camino at one time. It wasn't pretty.

I checked my torque after each 30 min session (4 per day for 3 days) and the lugs never loosened. I was at the low end at 135 ft pounds. 135 vs 150 is a big difference and as long as you are monitoring them closely, I don't see the need to honk down on them so much.

Just my .02 of a buck

 

[2015 Silver GT]

Read the thread.

I did and agreed with you. Did you read it?

 

[Stuntman]

I did and agreed with you. Did you read it?

You either didn't read Post #9 or don't understand sarcasm.

 

[Optimum Performance]

opcorn:

 

[melwff]

Does anybody know the grade rating of the studs? Looking at the chart below that 150 number is really on the high side for 14mm and would be in the grade 10 area at least.

http://www.dansmc.com/torque_chart.htm

 

[r1racer]

I broke my torque wrench trying to get to 150lbs...and the wrech was rated at 150lbs. I think if you are going to be tracking your car and/or in hot and cold weather then I would follow...otherwise 135 is more than enough especially if you pull your wheels off once or twice a year. At the very least just check the torque settings every month.

 

[honeybadger]

If you're tracking your car and checking lug torque frequently, I recommend aftermarket lugs. The OEM lugs are pretty soft. No beuno

 

[HoosierDaddy]

No you're wrong. I've been torquing my wheels for over 50 years and I've never tightened them to 150ft-lbs nor have I ever had a problem.

I just bought a Porsche GT3 with center lock wheels. Did you know those crazy krauts are trying to convince me to torque the single lug to 444ft-lbs??? What a bunch of BS. I've never had a problem with 80ft-lbs in all of my cars and the Porsche is no different.

:headbonk:

If by some chance you are NOT kidding, getting away with something is not proof its its a good idea. I knew someone who smoked 2 packs a day since high school and never had lung disease. Doesn't mean you or I would have the same results.

 

[sigintel]

Does anybody know the grade rating of the studs? Looking at the chart below that 150 number is really on the high side for 14mm and would be in the grade 10 area at least.

http://www.dansmc.com/torque_chart.htm

Those look like Japanese motorcycle pitch. A torque chart without thread pitch? Wow. Lol.
Grab a machinist reference or ask Ford.
For example, on M14x1.5 grade 10.9 Ford studs, some test data shows the following torque to preload relations:
153.0 nM (112.85 lbft), 85.3 kN (19176.202846 lbf)
182.0 nM (134.24 lbft), 90.4 kN (20322.728456 lbf)
209.0 nM (154.15 lbft), 95.2 kN (21401.811383 lbf)
257.0 nM (189.55 lbft), 97.5 kN (21918.871952 lbf)
299.0 nM (220.53 lbft), 99.5 kN (22368.489838 lbf)

200NM(148ftlb) is perfect on the “sweet” spot of the torque/clamping force curve.
Max durability and clamping.

Our studs are not “soft”, lol. They are 10.9 with Ford OEM grade traceability.

Highest torque accuracy for the dollar is an old fashioned split beam torque wrench. Extremely robust and repeatable.

148ftlb = 200NM which is totally standard for M14x1.5 10.9 OEM grade Automotive anti corrosion finish.

I did see preload drop after first track session on new 6G. Prolly dropped 10-20ftlb. Loosen all and retorqued. Seemed that the lugs just need to be torque several times to really have the lug seats forge to the perfect lug seat.

https://www.mustang6g.com/forums/showthread.php?p=1523800&highlight=Torque#post1523800

 

[Stripler]

I broke my torque wrench trying to get to 150lbs...and the wrech was rated at 150lbs. I think if you are going to be tracking your car and/or in hot and cold weather then I would follow...otherwise 135 is more than enough especially if you pull your wheels off once or twice a year. At the very least just check the torque settings every month.

You shouldn't use a torque wrench at its maximum rating. If it doesn't break like yours did, you could affect the calibration. I learned this the hard way just like you. It's not a bad idea to have a few different torque wrenches for different loads. I currently have three (250 lbs, 150 lbs, 50lbs).

For me, I've found if I don't torque to 150 or close, the lugs loosen - sometimes after a short drive, sometimes after a bit longer. I've had no issues torquing to 150 even with aftermarket wheels on my GT. On other cars I believe I did 100 or 110, but that won't work at all with my Mustang.

 

[CrazyHippie]

150 +/-15 Ft lbs. I tq mine to the lower end 135 FT lbs

Hi! My Wheel Designs dude (Vertini wheels) advised me to torque to 110-120, so I'm torquing to 130 with the tuner Gorilla Nuts. (Yes, Gorilla has them.)

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