Lug Nut Torque
#2
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Burt Gummer (11-13-2018),
jackra_1 (11-12-2018)
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scm (11-12-2018)
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#8
Appropriate timing... I just broke off a front stud using a 12" wrench. I was so shocked when it happened it actually triggered a headache. I did not cross thread the lug; I hand threaded it in place and was at the last stages of "opposite-diagonal" torquing the lug nuts, when one just kept turning. I would guess I was applying ~90-100 lb-ft (I am 170 pounds and was not bouncing or stepping on the wrench).
Then it snapped.
And you can't replace single wheel studs. You have to replace the entire wheel hub.. at $537 (plus labor). Jaguar won't cover it under warrantee, which I expected because I did it in my garage and they don't know if I was using an impact wrench on it (except for my word).
Then it snapped.
And you can't replace single wheel studs. You have to replace the entire wheel hub.. at $537 (plus labor). Jaguar won't cover it under warrantee, which I expected because I did it in my garage and they don't know if I was using an impact wrench on it (except for my word).
#9
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Appropriate timing... I just broke off a front stud using a 12" wrench. I was so shocked when it happened it actually triggered a headache. I did not cross thread the lug; I hand threaded it in place and was at the last stages of "opposite-diagonal" torquing the lug nuts, when one just kept turning. I would guess I was applying ~90-100 lb-ft (I am 170 pounds and was not bouncing or stepping on the wrench).
Then it snapped.
And you can't replace single wheel studs. You have to replace the entire wheel hub.. at $537 (plus labor). Jaguar won't cover it under warrantee, which I expected because I did it in my garage and they don't know if I was using an impact wrench on it (except for my word).
Then it snapped.
And you can't replace single wheel studs. You have to replace the entire wheel hub.. at $537 (plus labor). Jaguar won't cover it under warrantee, which I expected because I did it in my garage and they don't know if I was using an impact wrench on it (except for my word).
You can replace single studs but you have to remove the hub to do so, this has been covered here before.
The following users liked this post:
Tork Monster (11-12-2018)
#10
Appropriate timing... I just broke off a front stud using a 12" wrench. I was so shocked when it happened it actually triggered a headache. I did not cross thread the lug; I hand threaded it in place and was at the last stages of "opposite-diagonal" torquing the lug nuts, when one just kept turning. I would guess I was applying ~90-100 lb-ft (I am 170 pounds and was not bouncing or stepping on the wrench).
Then it snapped.
And you can't replace single wheel studs. You have to replace the entire wheel hub.. at $537 (plus labor). Jaguar won't cover it under warrantee, which I expected because I did it in my garage and they don't know if I was using an impact wrench on it (except for my word).
Then it snapped.
And you can't replace single wheel studs. You have to replace the entire wheel hub.. at $537 (plus labor). Jaguar won't cover it under warrantee, which I expected because I did it in my garage and they don't know if I was using an impact wrench on it (except for my word).
* There is a misconception that it is thread friction that holds on the nut. It's actually thread and stud deformation that prevents the nut from coming loose. The proper torque required depends on stud diameter and material/grade/hardness (all interdependent). Over tightening on a regular basis will fatigue the stud. Under tightening will...well, you know.
#11
Seeing the thread title, I thought the discussion would be about the recommended torque as there is often misunderstanding of the numbers where a low and a high number is given. However the Owner's Handbook is unequivocal - it is 92 lb.ft (125 Nm).
Also important is the tightening sequence which ensures no uneven stress is applied to the wheel.
What is not mentioned in the Owner's Handbook but appears in the Workshop Manual is application of a small amount of grease of the face of the hub and spigot to prevent the aluminium wheel binding to the steel hub as a result of exposure to rain and salt.
Graham
Also important is the tightening sequence which ensures no uneven stress is applied to the wheel.
What is not mentioned in the Owner's Handbook but appears in the Workshop Manual is application of a small amount of grease of the face of the hub and spigot to prevent the aluminium wheel binding to the steel hub as a result of exposure to rain and salt.
Graham
#12
#13
Yep- all of the above... I learned how to properly torque heavy machinery components decades ago on the job. Actually wrote the procedure in a few manuals for our equipment.
I cleaned & lubed the threads, finger tighten all five lugs first, then progressively tighten in an opposite-diagonal sequence, slowly increasing torque until you reach the final setting.
Although I didn't use a torque wrench, I was using a 12" wrench with one arm-strength.
I cleaned & lubed the threads, finger tighten all five lugs first, then progressively tighten in an opposite-diagonal sequence, slowly increasing torque until you reach the final setting.
Although I didn't use a torque wrench, I was using a 12" wrench with one arm-strength.
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So when one is torquing down the lug nuts after a wheel change after a year or so with no cutting oil present at all are you saying that one should put lube on the thread?
With all due respect I totally disagree with you as the manufacturer's specs are not for initial factory fitting but on the road use.
All articles that are engineering based support what I have stated.With Steel wheels maybe no problem with Aluminum absolutely.
This quote by an engineer sums it up quite well:
"Do exactly what the manufacturer of the vehicle states in service information. Why do I say this? The nut rotational friction and bolt clamping force are both affected by the choice of lubricant used or lack thereof. Almost all OEM's specify no lube. This is done for several reasons. Dry results in the most thread rotational friction, a most desirable attribute, this significantly reduces the chances of the lugs backing off and the wheel coming off.
The biggest concern is a wheel coming off at high speed. This is a highly dangerous event because the wheel accelerates ahead of the vehicle as it comes off at great speed and can and has caused deaths.
Of slightly less importance, but still relevant, is that lubricated threads create a higher clamping force for a given torque than specified. This can stretch the studs or bolts, warp the hub flange and/or brake rotor."
With all due respect I totally disagree with you as the manufacturer's specs are not for initial factory fitting but on the road use.
All articles that are engineering based support what I have stated.With Steel wheels maybe no problem with Aluminum absolutely.
This quote by an engineer sums it up quite well:
"Do exactly what the manufacturer of the vehicle states in service information. Why do I say this? The nut rotational friction and bolt clamping force are both affected by the choice of lubricant used or lack thereof. Almost all OEM's specify no lube. This is done for several reasons. Dry results in the most thread rotational friction, a most desirable attribute, this significantly reduces the chances of the lugs backing off and the wheel coming off.
The biggest concern is a wheel coming off at high speed. This is a highly dangerous event because the wheel accelerates ahead of the vehicle as it comes off at great speed and can and has caused deaths.
Of slightly less importance, but still relevant, is that lubricated threads create a higher clamping force for a given torque than specified. This can stretch the studs or bolts, warp the hub flange and/or brake rotor."
Last edited by jackra_1; 11-13-2018 at 07:35 PM.
#17
So when one is torquing down the lug nuts after a wheel change after a year or so with no cutting oil present at all are you saying that one should put lube on the thread?
With all due respect I totally disagree with you as the manufacturer's specs are not for initial factory fitting but on the road use.
All articles that are engineering based support what I have stated.With Steel wheels maybe no problem with Aluminum absolutely.
This quote by an engineer sums it up quite well:
"Do exactly what the manufacturer of the vehicle states in service information. Why do I say this? The nut rotational friction and bolt clamping force are both affected by the choice of lubricant used or lack thereof. Almost all OEM's specify no lube. This is done for several reasons. Dry results in the most thread rotational friction, a most desirable attribute, this significantly reduces the chances of the lugs backing off and the wheel coming off.
The biggest concern is a wheel coming off at high speed. This is a highly dangerous event because the wheel accelerates ahead of the vehicle as it comes off at great speed and can and has caused deaths.
Of slightly less importance, but still relevant, is that lubricated threads create a higher clamping force for a given torque than specified. This can stretch the studs or bolts, warp the hub flange and/or brake rotor."
With all due respect I totally disagree with you as the manufacturer's specs are not for initial factory fitting but on the road use.
All articles that are engineering based support what I have stated.With Steel wheels maybe no problem with Aluminum absolutely.
This quote by an engineer sums it up quite well:
"Do exactly what the manufacturer of the vehicle states in service information. Why do I say this? The nut rotational friction and bolt clamping force are both affected by the choice of lubricant used or lack thereof. Almost all OEM's specify no lube. This is done for several reasons. Dry results in the most thread rotational friction, a most desirable attribute, this significantly reduces the chances of the lugs backing off and the wheel coming off.
The biggest concern is a wheel coming off at high speed. This is a highly dangerous event because the wheel accelerates ahead of the vehicle as it comes off at great speed and can and has caused deaths.
Of slightly less importance, but still relevant, is that lubricated threads create a higher clamping force for a given torque than specified. This can stretch the studs or bolts, warp the hub flange and/or brake rotor."
This may be why I broke the stud... ? Maybe, maybe not... regardless I plan on cleaning but no WD40 on future applications.
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