: wheel lug nut torque



Bro-Ham
08-07-09, 12:22 PM
I have a 1979 Sedan deVille with 93-96 Fleetwood Brougham aluminum wheels. What is the magic number to torque these wheels onto the car?

jayoldschool
08-07-09, 03:12 PM
100 ft-lbs.

dirt_cheap_fleetwood
08-07-09, 05:12 PM
Just about every GM car is 100 lb ft.

cadillac_al
08-10-09, 11:04 AM
Most tire shops use max pressure on their impact guns so around here you end up with 250 lbs. I have bent 4 way bars trying to remove impacted lug nuts. It must not hurt anything because they don't give it a second thought.

dirt_cheap_fleetwood
08-10-09, 01:05 PM
^ I have NEVER heard of that. If you torque them down too much it will warp the brake rotors and possibly even the wheel itself. If there is a local shop near you doing that, I would not go back. If you are using an impact gun, you should use a torque stick to torque the nuts properly.

sven914
08-10-09, 02:16 PM
Torque sticks aren't all their cracked up to be; you drop one, it's garbage, a tech uses it backwards, it's garbage, if you tighten with it for too long, it's garbage, I've never trusted them. I may use one if I happen to have the correct one, but I alway re-tighten the wheels (to the correct torque) with my torque wrench. Most of the time, when I worked for Goodyear, I just tightened the wheels enough with my impact, on low, and then finished with the torque wrench.

Besides, most shops only have metric sticks. My car takes an 18mm, which is an 80ftlb, which is wrong.

brougham
08-10-09, 07:34 PM
A lot of places just go at it with an impact wrench wherever you are.

Bro-Ham
08-10-09, 09:17 PM
Thanks for all the input. A friend of mine who is anal retentive has a brand new torque wrench and he is going to twist them on to 100 tomorrow. I hand torqued them tonight when I switched my regular tire back on to replace the spare. Dave

JTraik
08-13-09, 05:23 PM
Thanks for all the input. A friend of mine who is anal retentive has a brand new torque wrench and he is going to twist them on to 100 tomorrow. I hand torqued them tonight when I switched my regular tire back on to replace the spare. Dave

100ft/lb is a dry setting. I always use anti-seize on lug nuts, thus i use about 110ft/lbs. Anti-sieze on lugs is great, keeps them from sticking and also ensures consistent torque values on all the lugs. Some people say its not a good idea but they cant explain why it isnt, they just seem to have heard it from somewhere at sometime. I get at the lugs every 4k or so and they are always at the values I had set them, they dont move but they sure come off great.

jey
08-13-09, 06:53 PM
100ft/lb is a dry setting. I always use anti-seize on lug nuts, thus i use about 110ft/lbs.

Lubricated setting should be LESS than the dry, using 110ft/lbs and anti-seize together might be trouble.

Think about it - if you lubricate a bolt and then tighten it at 100 ft/lbs, it's going to go down and through more threads than if you tighten it dry. If you tighten a RUSTED bolt it's going to take even more torque to get the same job done. (Which is also why it's important to keep your studs clean and in good condition.)

Many engineers have done tests to show that tightening a bolt with lubrication can cause up to 5X the amount of tensile stress on the stud/nut than in normal situations.

My opinion is, do what the engineers say - they don't just pull the torque specs out of thin air, they are calculated, and if it does not specify to use anti-seize then don't distort the torque spec by using it. There are times the engineers call for anti-seize (such as spark plugs. Porsche calls for them on Magnesium wheels.)

JTraik
08-13-09, 07:17 PM
Lubricated setting should be LESS than the dry, using 110ft/lbs and anti-seize together might be trouble.

Think about it - if you lubricate a bolt and then tighten it at 100 ft/lbs, it's going to go down and through more threads than if you tighten it dry. If you tighten a RUSTED bolt it's going to take even more torque to get the same job done. (Which is also why it's important to keep your studs clean and in good condition.)

Many engineers have done tests to show that tightening a bolt with lubrication can cause up to 5X the amount of tensile stress on the stud/nut than in normal situations.

My opinion is, do what the engineers say - they don't just pull the torque specs out of thin air, they are calculated, and if it does not specify to use anti-seize then don't distort the torque spec by using it. There are times the engineers call for anti-seize (such as spark plugs. Porsche calls for them on Magnesium wheels.)

Sorry, I meant to convey that under my normal wet torquing its equivalent to about 110ft/lbs dry torque.

Engineers established dry torque settings because it is more practical to assume that sloppy gas station mechanics would be to lazy to apply lubricants... hell they rarely properly torque the things at all. I like re-engineering things where I see fit, this sort of thing is certainly one of them and so far it has been nothing but success :).

jayoldschool
08-13-09, 10:21 PM
I always use anti-seize on lug nuts, thus i use about 110ft/lbs. Anti-sieze on lugs is great, keeps them from sticking and also ensures consistent torque values on all the lugs. Some people say its not a good idea but they cant explain why it isnt, they just seem to have heard it from somewhere at sometime.

This is a MAJOR no-no. The torque value is DRY. Using a lubricant or anti seize changes the torque that is actually applied. GM is VERY specific about this. Please, take your lug nuts off, clean everything well with brake cleaner, let dry, replace, and torque to spec.