Why 300 ft/pds to install car tires?

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It had to be around that reading.Customer comes over for a brake inspection and had 4 new Goodyears put on by Goodyear dealer.Two of us with a breaker bar and a piece of pipe got 4 off one tire and the last one the stainless cover was rounding,gave up on the other 3 tires..darn...why do the tire joints crank the heck outa them...are the torque sticks that hard to use.He's going back to the tire shop before I snap/strip something...second vehicle this month that had the lug nuts on so tight there is NO-WAY anyone would get them off with what they had in the trunk on the side of the road...done venting now..100 ft/pds is all I ever use on lug nuts and NEVER had any complaints in 25 years
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Can you imagine having a flat on the road and trying to change one of those? I bet they were put on full torque with one hit of the air wrench, and not done in proper sequence either........
 
quote:

Originally posted by Ken4:
Even 100 ft-lbs is too excessive. Mine specs for 78 ft-lbs.

I'd say 90% of vehicles call for 80-110 ft/pds of torque on wheel lug nuts...I allways use a smidge of anti-seize and 100 ft/pds and my customers love me for it...never had any problems with a loose wheel.. from Honda's driven hard to slow driven Buick Roadmasters...SUV'S,P-ups everything in between... never a problem with loose or stuck lug nuts
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quote:

Originally posted by Drew99GT:
It's quite simple: many people simply don't care!

Well I know one tire shop thats going to care.My last customer with a Jeep Grand Cherokee has documentation from myself and another shop stating the lug nuts were tightened beyond reason and damaged his lug nuts,studs,rotors and is in litigation as we speak..."squeeky wheel gets the oil"
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This is also a pet peeve of mine. The first thing I do upon trading vehicles, is to check the lug nuts torque. I too had to use a piece of pipe on a breaker bar to loosen the nuts on my last two vehicles.

Over-torqueing lugs is just as dangerous as having them too loose. The tire shops that do this should train their employees better.......
 
Cripes, I had the A/C worked on in my 94 Corolla the other day; most shops will take a spark plug out on an easy to get at 4 banger just to see how things are lookin. Every single shop I've taken the car to that does this, installs the plugs to just under thread strippage. I mean dayum! That'll just destroy the gas seals and distort the plug, rendering it useless at removing heat from the combustion chamber. Like I said, many just don't care (well, they care about flat rate and their pay check
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quote:

Originally posted by Mitch Alsup:
Just for reference purposes:

The Magnesium wheels on Ferraris should be TQed to 72 lb-ft.


And thats just what the ones on mine are tq-ed to
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. The Carrera GT gets 72.5 lb/ft
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.
 
quote:

Originally posted by Greaser:
It had to be around that reading.Customer comes over for a brake inspection and had 4 new Goodyears put on by Goodyear dealer.Two of us with a breaker bar and a piece of pipe got 4 off one tire and the last one the stainless cover was rounding,gave up on the other 3 tires..darn...why do the tire joints crank the heck outa them...are the torque sticks that hard to use.He's going back to the tire shop before I snap/strip something...second vehicle this month that had the lug nuts on so tight there is NO-WAY anyone would get them off with what they had in the trunk on the side of the road...done venting now..100 ft/pds is all I ever use on lug nuts and NEVER had any complaints in 25 years
rolleyes.gif


Which is why I get tires from the same shop all the time.....they use only torque wrenches for tightening.
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quote:

Originally posted by shortyb:

quote:

Originally posted by Mitch Alsup:
Just for reference purposes:

The Magnesium wheels on Ferraris should be TQed to 72 lb-ft.


And thats just what the ones on mine are tq-ed to
wink.gif
. The Carrera GT gets 72.5 lb/ft
grin.gif
.


The central, single 'lug-nut' on the Porsche Carrera GT takes over 250 ft/lbs of torque to tighten. Porsche gives you a special torque multiplier tool for the locknut. I would not sit in the car with the wheels only torqued to 72 ft/lbs.
 
lugnut torque is based on the stud thread size.
Only if the rim material is soft, would it then limit the amount of clamping force of the lugnuts and lower the torque they're supposed to be tightened to.

majority of wheel studs are 1/2x20 (1/2 inch diameter), and torque for that size bolt/stud is 100 lb-ft max for dry threads, simple as that.

the smaller cars have 7/16" studs, which is why you see lower torque specs for those wheels. And the 3/4 to 1-ton trucks and suv's with the 8 lug wheels, are 5/8" which is why they go to 140 lb-ft. The purpose of torquing a bolt/stud/ is so that it stretches and not only provides necessary clamping force but also prevents the nut from coming loose from vibration.
 
Poper tension also helps the fatigue life of the bolt/stud. The main cause of broken lugs is not overtightening, but fatigue failures from loose ones. My 1500 series Chevy had the larger 5/8 studs, but only five of them. The tightening spec was 120.
 
Jimbo and 1EMF, it's nice to see a couple of people posting who actually understand how fasteners work.

Too many people believe that all that matters is that the fastener doen't fall off.
 
My local honda dealer/stealer did the same thing. Couldn't get the wheel nuts off after they rotated the tires. Over 150ft.pounds. I had to give up on removing nuts myself. Had to waste another trip to the dealer/stealer to get them properly torqued. Why not just use a huge breaker bar? These honda studs can break if you have to force the nut off. If it broke, I wanted the dealer/stealer to do the breaking.
 
quote:

Originally posted by Greaser:

quote:

Originally posted by Kestas:
For passenger car studs, 400 ft-lbs is about the time they'll start necking.

Good to know but how many times will it take to overtighten the stud before it stretches too much and snaps...it's not that uncommon.


You won't have to worry about a bolt snapping when tightening it. Usually they brake when corrosion causes the removal torque to be much higher then what you tightened it too.

-T
 
Went to my local Firestone dealer last month to buy a set of new Destination LE tires. When I got back home I decided to check, all four wheels had overtightened lugs to the point that I had to step\jump on the break bar to get them loose. WAY too tight. What's worse, 4 of the 5 on one wheel were so loose I could remove them with my fingers. I called and spoke to the manager to tell them they put me in danger. I told him to start using a real torque wrench before someone gets hurt. This is the reason why I do whatever I can myself.
 
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