Wow, 150 Ft lbs of wheel lug nut torque!

[HuntingPudel]

Reminds me to put one of my torque wrenches and an extension and some sockets onto my list of stuff to bring whenever my car is ready in 2029.

What hex size is the standard lug nut? 21mm, I am guessing from the OD of the stud.

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[Benny’66]

My car, too. My dealer didn't have much time between the truck arriving and my driving off, so it makes sense that they wouldn't have fussed with re-setting lugnut torques.

My torque wrench has been well cared for but not recently calibrated. I certainly got motion while torqueing up to 130 ft-lb on every wheel, nearly every nut. I'll let it sit overnight before going further.

This is the kind of thing that a forum is great for. Not arguing over opinions, but comparing notes on things that have physical units.

The factory is using multi-spindle electric nutrunners that run all lugs at the same time. Each spindle is individually monitors and controlled. The controller measures dynamic torque across the whole tightening cycle. Typically the controllers would be set up to start measuring angle (degrees) of rotation from a starting torque value, probably 130-135 in this case, until the spindle reaches the final torque set point (150), to ensure proper seating and clamp load. They are very accurate. But (there’s always a but), when we common folk check these lugs, we are doing it with static torque wrenches. And there is NO correlation between dynamic and static torque. Typically the static torque wrench value will be higher because you are overcoming the “break free” friction of the fastener and the torque (clamp load). Back in my auto engineering days, my plant purchased an IR digital wrench ($8000) that could be set to measure torque after so many degrees of rotation to simulate a dynamic torque reading. At the end of the day, it’s essentially all just black magic, snake oil, smoke and mirrors, etc.

Most likely in this scenario the factory electric nutrunners has multiple tightening sequences programmed into it with different final torques for different wheel setups and the operator forgot to pick the right one.

As I tell my staff and operators in my current factory all the time: “Trust, But Verify”.

 

[phidauex]

What hex size is the standard lug nut? 21mm, I am guessing from the OD of the stud.

Yes, a 21mm socket!

 

[phidauex]

The factory is using multi-spindle electric nutrunners that run all lugs at the same time. Each spindle is individually monitors and controlled. The controller measures dynamic torque across the whole tightening cycle. Typically the controllers would be set up to start measuring angle (degrees) of rotation from a starting torque value, probably 130-135 in this case, until the spindle reaches the final torque set point (150), to ensure proper seating and clamp load. They are very accurate. But (there’s always a but), when we common folk check these lugs, we are doing it with static torque wrenches. And there is NO correlation between dynamic and static torque. Typically the static torque wrench value will be higher because you are overcoming the “break free” friction of the fastener and the torque (clamp load). Back in my auto engineering days, my plant purchased an IR digital wrench ($8000) that could be set to measure torque after so many degrees of rotation to simulate a dynamic torque reading. At the end of the day, it’s essentially all just black magic, snake oil, smoke and mirrors, etc.

Most likely in this scenario the factory electric nutrunners has multiple tightening sequences programmed into it with different final torques for different wheel setups and the operator forgot to pick the right one.

As I tell my staff and operators in my current factory all the time: “Trust, But Verify”.

Thanks - well explained. The more I learn about fastener torque the more complex I realize it is. I think fastener relaxation + static torque wrenches are probably causing a lot of people to way over-torque their lug nuts, or at least unnecessarily overtighten them, even if they aren’t being damaged.

 

[zvez]

Sad thing is that I've NEVER seen a tire shop use a torque wrench.

Even more disheartening is when they use an impact wrench to TIGHTEN the lug nuts.

 

[MachEGTPilot]

Sad thing is that I've NEVER seen a tire shop use a torque wrench.

Hey Chuck, what facility are you at. Retired ZAU controller here.......

 

[BillPitman]

From what I have observed, most don’t. I have seen lots of shops just use a deep socket on an impact gun. Funny thing is, I got a puncture recently on a bad place in one of the Fusion Energi’s tires. Bought a used tire at a hole in the wall shop and he used an impact to remove the wheel but hand tools and a torque wrench to reinstall. Of course, I re-torqued with my recently calibrated wrench.


Good thing I have two 1/2” Protos. The small one from the 1980s goes up to 150 and is damn-near perfect every time I get it calibrated. The bigger one is much newer and goes to 250. It was within spec when it was last calibrated.

Where do you get torque wrenches calibrated?! Bill

 

[HuntingPudel]

Where do you get torque wrenches calibrated?! Bill

You can send back to the manufacturer if you purchased a higher-end brand (they will charge you to recalibrate). If you bought Snap-on, MAC, etc. some of their drivers have calibration equipment on their trucks (and will charge you to recalibrate). There are also third-party calibration services. ??

 

[BillPitman]

You can send back to the manufacturer if you purchased a higher-end brand (they will charge you to recalibrate). If you bought Snap-on, MAC, etc. some of their drivers have calibration equipment on their trucks (and will charge you to recalibrate). There are also third-party calibration services. ??

Thanks….B

 

[Kmp14]

Reviving this old thread. Thanks for all the good info in here. I just did my 10k rotation, and now the tpms tire location is incorrect. Is this something we can reset?

 

[azerik]

It’ll catch up in a drive cycle. Usually 20 to 40 minutes.

 

[Kmp14]

It’ll catch up in a drive cycle. Usually 20 to 40 minutes.

Thanks!

 

[txaggies07]

Wow, I didn't realize the torque was so high on these wheels. Looks like I need to go tighten mine further. Thanks for the info.

 

[azerik]

I've pulled my wheels off probably 50 times in the last year. My Harbor Freight $20 torque wrench has more than paid for it's self several times over.

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