Concern with lug nuts

[kz]

No issues at 150. Keep in mind the studs are usually what would break, and they're good to 150ft/lbs per factory specs.

Don't cross-thread the lug nuts, use a good torque wrench, and don't torque them down when the studs are overly hot and you should be fine.

So far I found lug nuts to be much weaker than studs (found out by missing the fact my impact wrench has been accidentally set in wrong rotation direction and wondering why the hell that nut isn't coming off)

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[Need4SpeedMotors]

So far I found lug nuts to be much weaker than studs (found out by missing the fact my impact wrench has been accidentally set in wrong rotation direction and wondering why the hell that nut isn't coming off)

That would do it.

 

[VinnAY]

Never knew that. I always thought it was the size of the stud, thread pitch, etc.

Learn something new everyday!

No you're right and he's wrong.

 

[BlueThunder]

I just installed the SVE Drifts 19x9.5's all around. I’m not sure if this is necessary, but I always make sure my lugs are tightened properly after I hear a “click” sound while I torque them down, however, I am not hearing any clicks after tightening them and I’m worried they might not be tightened down correctly. Thanks.

As a precaution and because I've had issues with other types of things that need torque, I do it in increments. Up to 90/100 I'll hand-tighten, then to 60ft, then to spec. Little extra work adjusting your wrench but I feel better doing it that way. If you think your wrench is having an issue try the same thing, do something very light like 50/60, then up to 110, then to factory spec.

 

[scoggy_doogan]

I bought this 150 ft lbs model:

https://www.amazon.com/TEKTON-24335-2-Inch-ft-lb-13-6-203-5/dp/B00C5ZL0RU

Affordable and seems to work fine, very well reviewed also.

I have not had any issues to date with 150 ft lbs on my 2015.

Just an FYI, torque wrenches are less accurate at the extremes of their ratings. A 50-250 ft lbs torque wrench is a good investment for most suspension and wheel bolts.

That being said, I only torqued my wheels to 81 ft lbs the 1st time I rotated my tires (torque spec on my infiniti) and they didn't loosen over 2 months. :shrug:

 

[HISSMAN]

I bought this 150 ft lbs model:

https://www.amazon.com/TEKTON-24335-2-Inch-ft-lb-13-6-203-5/dp/B00C5ZL0RU

Affordable and seems to work fine, very well reviewed also.

I have not had any issues to date with 150 ft lbs on my 2015.

I have the exact same wrench. Love this thing.

 

[CCCP1999]

I bought this 150 ft lbs model:

https://www.amazon.com/TEKTON-24335-2-Inch-ft-lb-13-6-203-5/dp/B00C5ZL0RU

Affordable and seems to work fine, very well reviewed also.

I have not had any issues to date with 150 ft lbs on my 2015.

I may get that myself.

 

[Optimum Performance]

I'm going to word this very carefully. Not having seen the wheels in person I can not comment on the surface area of the wheel for the nut; the conical seat.

What I can say is the car is designed for 150ft/lbs. If you are running an aftermarket wheel that requires "special" lugnuts becasue the wheel was designed for 1/2" studs and the nut does not pysically fit into the wheel hole please make sure the "special" nut is not bottoming out on the tip of the stud. If you are not sure, take a paint marker, a small ball of clay and mark the end of the stud and run the nut down. Look for bottoming in the cap of the nut.

We keep hearing of S550's and Shelbys with broken studs and they all can be attributed to closed end lug nuts. They get do not clamp the wheel, the stud is stressed and "twisted off" then the studs fail at that point due to the loading from the non clamped wheel.

I would be concerned with any wheel 'designed' for this car that can not take the factory torque spec. Both the 1/2" and 14mm open ended lug nuts have the exact same size and shape seat so I'm not really sure what wheels are made with a conical seat that is a different dimension that requires less torque. 80ft/lb's is half the spec. That is the same as hand tight IMO.

The conical seat no matter how deep it is typically only makes contact with a section of the nut surface. I have personally tried mulitple nuts on the S550 to determine contact area on the products we use. The nut will leave a witness mark inside the wheel where it makes contact and the wheel will leave a mark on the nut.

The torque spec should be the torque spec. Do not deviate from this.

That said, if the wheel manufacturer provides you with a printed S550 specific set of instructions for wheel torque and lug nuts follow them. Verify the that the nuts do not bottom on the tip of the stud if they are not open nuts.

If you are running wheels designed for 1/2" studs, run 1/2" studs. Measure the wheel flange dimension and compare it to the Factory wheels. If the flange is thinner than the factory wheel you will need longer closed end lug nuts. The splined nuts may be too short.

 

[2morrow]

The torque spec should be the torque spec. Do not deviate from this.

Totally agree.

 

[sigintel]

148 ft lb *edit corrected to Ford spec, not 150

The 150 ft lbs is used on the OE wheels only, that lug nut nut has a larger contact area to the wheel so it can take more torque. On aftermarket wheels and lugs the contact area is smaller so 85-95 ft lbs is recommended.

:eyebulge:

uhh. Is it ok to ask recommended by who? Was there a source and context to this recommendation?

Sounds like a safety issue.

My limited understanding (could be wrong): Insufficient wheel stud torque results in the wheel attempting to move or rotate in relation to the hub placing massive bending loads on the studs. Studs then fail in fatigue after time.

http://www.crashforensics.com/wheelandhubfailures.cfm

https://www.google.com/search?q=Stud%20preload&rct=j#q=wheel+Stud+preload

https://www.google.com/search?q=Stud%20preload&rct=j

I suspect Ford will tell you that any wheel (aftermarket wheels included) must handle the required "Preload" (tension force) of the stud on the wheel per Ford spec to establish the rated "Clamp Force". There is no optional lower allowable "Preload" or "Clamp Force". :ford:

Torque is used to establish what is referred to as "pre-load". This is the tension in the lug stud that Ford has determined is necessary for the lateral, longitudinal and torsional loads that are possible in work case impacts and handling: pot holes, curbs and spins off the road surface.

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)

So 148 lbft torque would be like 21,000 lbf per lug.
What clamping force do you get at 95 lbft?:eyebulge:
Be sure and multiply that by 5 studs to see the over all deficit in clamping force.

 

[Kenbike]

Some great information guys. Also aftermarket wheels bolt pattern must match the factory hubs and the wheels holes must be set for 14 mm studs vs. 1/2".
The inside dia of the wheel that slides over the hub must be correct due to our cars being hub centric.

 

[ForTehNguyen]

to do the lugs the 250 ft lb max one is a lot more preferrable. Never ever max out a torque wrench its inaccurate at its full range. Plus the longer 250 ft# wrench will make it easier for you to torque down the lugs and the larger fasteners if you work on the suspension. Find it strange that people freak out at 150 ft# lug nut spec but have no issue with the suspension components with the same torque and similar fastener size

specs exist for a reason

https://www.amazon.com/TEKTON-24340-2-Inch-ft-lb-33-9-338-9/dp/B00C5ZL1NS

 

[CCCP1999]

to do the lugs the 250 ft lb max one is a lot more preferrable. Never ever max out a torque wrench its inaccurate at its full range. Plus the longer 250 ft# wrench will make it easier for you to torque down the lugs and the larger fasteners if you work on the suspension. Find it strange that people freak out at 150 ft# lug nut spec but have no issue with the suspension components with the same torque and similar fastener size

specs exist for a reason

https://www.amazon.com/TEKTON-24340-2-Inch-ft-lb-33-9-338-9/dp/B00C5ZL1NS

I will order this one as well. Plus i have very big telescope mounts i could use this with.

 

[dev1360]

Never knew that. I always thought it was the size of the stud, thread pitch, etc.

Learn something new everyday!

It IS based on the size of the stud. He is flat out wrong. They want a lower torque so you don't tear up cheap cast wheels.

 

[2morrow]

https://www.amazon.com/TEKTON-24340-2-Inch-ft-lb-33-9-338-9/dp/B00C5ZL1NS

This is great, thanks!

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