Torque for Lug Nuts

72 ft-lbs.

I use 75, my torque wrench is in increments of 5...

 

I've stuck a lot of wheels on a lot of cars in my time, but I have never heard of anyone torquing a lug nut until I came here. Why does a Ferrari require the lug nuts torqued? And why do I not care about torquing mine?

 

I check the torque on -all- my vehicles' wheels. Almost losing one at the age of 17 kinda stuck that lesson in my head.

Because they're used a lot harder than minivans.

Because you put 200 miles a year on them.

 

Ferrari 308/328's don't have lug nuts.... they have lug bolts

 

Never torqued a lug nut or lug bolt other than by hand and feel...and I'm sticking with it.

 

Yep. I did check once. I was a little tighter. But by experience is fine for me.

 

+1

 

Jeez get torque wrench. Cheap insurance.

Bolts are like springs. Torquing them to the right values sets the spring preload.

Torquing ensures the life of the parts and can actually protect the parts from breaking. In a multiple bolt joint (like your wheel!) torquing makes sure all the bolts are at the same tension. One bolt looser or tighter than the rest will cause that part of the joint to load up first or last. Having them all the same, lets the part load up evenly.

Any joint that takes any load and especially one that keeps your car on the road... should be properly torqued using a decent torque wrench.

 

Why would tire installers do if it wasn't a requirement of all manufacturers? It's not just a Ferrari thing.

 

I'm sure torquing the nuts is a good idea, especially on the track, but really, how many wheels on the road are actually torqued? I'm thinking that if torque on a lug nut was so almighty important manufactures of high end cars like Ferrari etc. would provide you with a torque wrench in the tool kit instead of a lug nut wrench. I remember once tightening the nuts on my VW Van with a large Crescent wrench. I put a few thousand miles on that wheel. Of course I was usually so loaded then that I wouldn't know anything was wrong until the tire was rolling on ahead of me.

By the way Tillman, wouldn't 200 miles be enough to find out your wheel is going to fall off? I'm planning 300 this year.

 

Right On!!!

In the old days of stamped steel wheels, you could get away with hand tightening, or running them on with an impact wrench. Usually the lugs ended up over-torqued, but not to the point of failure.

With alloy wheels torqueing became critical. It's very easy to ruin an alloy wheel, esp. an Al wheel with improper torque. Over-torqueing can actually crush the area under the lug resulting in cracks forming & eventually the wheel will break! Under torqueing can result in the wheel coming a bit loose & destroying the lug nut/bolt conical centering surfaces.

Just about all of them!!! These days tire retailers & car dealers all use torque nuts, or controlled torque wrenches. A few use torque bars on impact wrenches, but they aren't very accurate.

Only hand tighten lugs in emergencies, or when temporarily installing a wheel to move a vehicle being serviced around by hand.

 

Many years ago when I was living in Chicago I began my BMW phase of car ownership. My local mechanic had warned me of the dangers of not torquing alloy wheels properly. He mentioned the same pitfalls as has already been mentioned here...warping, cracking, etc.. up to and including bolts loosening.

I was skeptical until I felt the rear end of my Bavaria start to feel pretty squirrelly at speed on the Dan Ryan Expressway. I pulled off at the nearest exit, felt the left rear drop, looked in the rear view, could see sparks flying and only a glimpse of my wheel continuing down the highway at speed.

I never did find the wheel and tire and from that day forward I have always torqued my alloys....

Brock

 

An often over looked reason for a prpper torque is to insure even distribution around the wheel as it can effect rotor warpage if done with an impact gun ( most major tire dealers ) set to "good and tight" specs. Remember the lug bolt will "stretch" over time too.
As a past GM service rep we initiated torque sticks back in the eighties to reduce the number of warped rotors warranty claims due to improper torque procedure.
You can buy a $30 rotor at AutoZone for your mini van, not so for your F-car model...

 

Ditto. And I'm with Verell on this one. Yeah, on most "driver" cars, the gorillas in the tire stores just use the impact wrench on them. I've had them tighten lug nuts down so tight that I literally could not get them off. And I've seen a couple of alloy wheels cracked (fortunately, none of mine) by overly aggressive tightening with impact wrenches.

So, yes, I hand torque the wheels on the Ferrari and the other cars I have that have alloy wheels. YMMV, but it works for me.

 

I've torqued the wheels on every car I've owned for many years now. I don't think it should be regarding as something that's sacred in the Ferrari world. IMHO there are several reasons for doing it:

1. You shouldn't blindly trust what the guys in the local garage have done. It must be pretty frustrating to get a flat and then discover that they've put the things on so tightly that you cannot undo them without a breaker bar.

2. Something I heard years ago was that incorrectly torqued nuts can lead to warpage of rotors and/or rims.

Therefore, given that it takes seconds to orque the wheel nuts, and that we should all own a torque wrench for our other jobs anyway, it really seems like a no brainer to me.

 

I can consistently torque the lug bolts within a couple ft/lbs of spec by hand - it comes with experience.

For me, by hand is superior to use of tq wrench as I can also feel the stretch and the CoF of the mating surfaces with careful touch, and adjust a few lbs up/down when appropriate.

I've been consistently "unimpressed" with the technical sophistaction of tire shops...

 

+1

 

The proper torque is actually less tight than one might expect, and I bet most who tighten by feel tighten quite a bit more than the torque spec. Probably not a problem unless tightening becomes extreme most likely with with an air wrench. My 88 Mondial wheels have a plastic type of hub bonded in some way to the alloy. Looks more fragile that many wheels I have seen, and therefore makes sense to torque carefully to a bit higher than the 75 ft/lb spec ( I do 90 lb., 75 lbs. just seems barely tight). I am curious if the older concave wheels type also had this partial plastic construction, never seen this other than on my ferrari wheel?.

 

I started torquing wheels on everything when in HS in the 70s on way home from getting new tires from Sears for a Datsun PU and heard clunking in the hubcap half way home. Looked and 2 lug nuts were loose in there and several others on truck were not finger tight !>?

Since then always check after shop with torque wrench in parking lot before leaving or drop off wheels like I did the 86 16 inchers today to get new shoes for the 82 Mondial. The BFG G forces should be ready Friday. Noticed a cut or split in one of the old TRXs at the sidewall tread junction last time got gas so car been parked a couple weeks ;-(.

With Mags, retorque after first trip out, 50 miles and 150 miles out.

 

Over time use of too much torque will make the seat where the shoulder of the lug bolt mates to the wheel mushroom out, making the wheel useless.

 

It's really just an issue of the correct or incorrect way to do something.

Proper torque is the correct way to do it.

But if you don't want to, don't. It's your car.

I torque everything properly with mine.

 

I'm with you on being unimpressed by tire shop's employees. Discount Tire's policys will lead to correctly torqued wheels, but uneducated employees can foul that up.

However, the torque spec by a manufacturer accounts for CoF, thread pitch, surface area of the bolt/wheel, metal stretch, etc. For example, what feels like 115 Nm on a coarse thread will be over torqued on a fine pitch thread. But if you work on one type of car all day, you can be consistently "close enough" for sure. It's just too difficult to argue with a calibrated procedure, especially when accounting for liability.

 

Wow 75 is a really light torque, not much more than finger tight. I get that easily just snugging them with my breaker bar prior to lowering the car. Is it because of the wheels are magnesium? I have tracked and raced cars for years and always use 95 for every application and have never had a wheel problem. That includes steel nuts on aluminum wheels on the Honda race car, aluminum/aluminum on Porsche street cars, and just about every other combination. I can't imagine driving aggressively with a torque of 75.

 

75 foot pounds is not much more than finger tight?? If you can tighten a lug bolt anywhere near that with your fingers I'll be wildly impressed. The factory specified torque is perfectly fine for any type of driving if they are tightened correctly and there are not defects. Cheap torque wrenches, defective, no longer in calibration, incorrectly used, lubricated bolts, grease in the hub hole, paint on the wheel bolt insert etc. etc. can cause what someone thinks if 72 or 75 foot pounds to be something quite different.

The length of most 1/2' drive torque wrenches kind of hides from you, the amount of power you are applying. If you could get a 1/2' torque wrench that were only, for example, 8 inches long you would certainly get a different "picture" of what you are doing.