Loose Lugs and aftermath

ratkc135 · Jan 30, 2019

mk3 said:
The possibility that a second tightening event is possible doesn't mean that the joint "needed" it. It just means that it is possible to go tighter.

This is the case for nearly every joint I have ever tightened. if I wait one day and turn the wrench again there is a possibility it will turn a little more ( I studied this at work about 15 years ago). if I turn the wrench up it will go a little more (which of course seems obvious). if "more" means that something was too loose then we would never be satisfied until the bolts were twisted off.

It is not reasonable that a wheel will fall off after driving away from a service shop just because someone didn't re-tighten - wheels would be coming off all over the place.

The original torque specification will have headroom for tolerances, embedding and twist of the bolt.

Wasn’t implying they would fall off. I’m not a expert mechanic. All I was saying is when I recheck my torque wrench will turn some a fraction...not much...(maybe half a turn ish at most) until it clicks again. Others it clicks before turning them. Which leads me to believe the lugs were no longer at 90 ft-lbs (of course there is some degree of error based on the accuracy...or lack thereof) of the torque wrench used. I’m not intending to make it tighter...just verify they are still at 90 ft-lbs.

I also wasn’t implying the lug needed it or otherwise all hell would break loose! Lol

Is it not possible that a fastener would not be at the same torque in this case where the wheels are spinning/vibration, etc? I’m curious now about the engineering principles involved now lol

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BobnOH · Jan 31, 2019

Believe it's simple material physics (some say everything is based on physics). Materials change size with temperature, different materials change at different rates. So a steel wheel held on by steel nuts on steel studs against a steel backing will be fairly stable. Your alloy will change at a different rate.
As a practical matter you pretty much never see this on our cars. But it is recommended to recheck torque after a given time interval (1 week?). I've never done this.

Years ago when I worked construction in Atlanta, we had a van with alloys, had new tires put on first thing in the morning, loaded it up with 3000# of material, later that day a wheel came off on the highway. Typical summer day down there was 65 in the A.M., 100 by afternoon.

Genesis · Jan 31, 2019

The risk is that there is a small amount of "something" that prevents full metal-metal contact between the wheel and hub, and road vibration or simple time allows it out of the gap. You now have one or more lugs that are either not torqued to spec or in the worst case, not even snug-tight.

Most places will, after mounting wheels, go do a couple of fairly aggressive figure-8s in the parking lot with the car, and then retorque. This reduces the risk of it happening by a lot.

Of course paying attention to any possible corrosion or gunk on the wheel and hub (and wire-wheeling the hub lightly to get any corrosion or junk off the seating face) will make it unlikely to happen too.

Lugs should never be tightened with air tools -- only a manual torque wrench -- but some places (still) do.

mk3 · Jan 31, 2019

The best reference I have found for threaded joints, tightening, locking etc. is

http://www.boltscience.com/pages/vibloose.htm

http://www.boltscience.com/pages/tighten.htm

It is important to remember a couple of things
1. the intent of the joint is to hold clamping pressure - stretching the bolt to a certain amount of force and stretch. the goal is NOT to have a certain amount of torque applied - that is just a means to an end.

2. Everything is elastic. You can think of the bolt as a 'rubber band' or 'spring' but obviously a very strong and rigid one. The wheel that you clamp is also elastic, some wheels more than others.

BobnOH · Jan 31, 2019

Genesis said:
................snip...........................
Lugs should never be tightened with air tools -- only a manual torque wrench -- but some places (still) do.

They sure do. Some folks, when having new tires fit, will take the lug wrench from the trunk and ask the hack to remove just 1 fastener.

Genesis · Jan 31, 2019

I rotate my own tires on every oil change. I've yet to have my hand-torqued lugs loose when I go to do it, and I do not re-torque after a while. But I also pay attention to the flange surfaces and make sure they're clean before bolting things up in the first place, as it's that clamping force that holds things together and that relies on a pair of nice, clean mating surfaces.

Nero Morg · Jan 31, 2019

20IndigoBlue02 said:
Since you are lubing the threads, are you torquing to 89 lb-ft? If so, you are over-torquing

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I set the torque wrench at 85FtLbs, and my snap on click style torque wrench is about 5lbs under set spec at the moment. Just haven't taken the time to get it calibrated. Been setting it about that much for a while and haven't had any issues.

WantingaTDI · Feb 7, 2019

I sent the following note to the President of Costco about a week ago and today received a call from the claims adjuster agreeing to pay the full amount! Thanks for your technical assistance.

[FONT=&quot]
[/FONT]
[FONT=&quot] -------------------------------------------------------------->//Return Address///
[/FONT][FONT=&quot]
[/FONT]
[FONT=&quot][FONT=&quot] -------------------------------------------------------------->[/FONT]January 27, 2019[/FONT]

[FONT=&quot]W. Craig Jelinek, President[/FONT]
[FONT=&quot]999 Lake Drive[/FONT]
[FONT=&quot]Issaquah, WA 98027[/FONT]

[FONT=&quot]RE: Costco Claim:-------------------[/FONT]

[FONT=&quot]Mr Jelinek—[/FONT]

[FONT=&quot]I would like your assistance resolving an unfortunate experience I recently had at the Pentagon City Costco Tire Service Center associated with the aforementioned claim number and failure to reach a suitable resolution with Costco’s [/FONT][FONT=&quot]third party administrator[/FONT][FONT=&quot], [/FONT][FONT=&quot]Gallagher Bassett Services.[/FONT]

[FONT=&quot]I brought my VW Golf into Costco’s Pentagon City Tire Center to have the tires rotated and a tire leak checked on December 15, 2018 and less than two weeks later I had a very scary thing happen; my driver side wheel lug nuts came off while driving on the highway. As soon as the steering wheel started pulling, I pulled the car to the side of the road and found the wheel tiled at a ~15 degree angle with ½ a lug nut remaining on the driver side wheel. I promptly brought the car to Costco in Fredrick, MD (close to the highway were I pulled over). [/FONT]

[FONT=&quot]Costco had the car towed to the nearest Volkswagen mechanic for full evaluation and had me fill out an incident form. The Volkswagen dealer in Fredrick Maryland found damage from the incident resulting in damage to the car’s driver side alloy rim, hub, lug nuts, brakes and rotor. The total damage estimate came out to $1,700.
[/FONT]
[FONT=&quot]Gallagher admitted negligence on behalf of Costco for failure to properly secure the wheel and agreed to pay for damage caused to the alloy rim, hub and lug nuts ($909) but has refused to cover the remaining damage associated with this incident to the brakes and rotor ($790), claiming it is ‘unrelated’. The damage is unequivocally related. [/FONT]

[FONT=&quot]I would like your assistance in resolving this matter amicably. Feel free to call me at -------.[/FONT]

[FONT=&quot] Respectfully,[/FONT]

/s
[FONT=&quot]--------
[/FONT]
[FONT=&quot](Costco member for the last ~20 years.)[/FONT]

Nero Morg · Feb 7, 2019

Another win for the little guys. Congrats man. Are you going to service the other side rotor/pads to get equal brakes? Or say screw it and do one

WantingaTDI · Feb 8, 2019

NM- VW replaced both brakes and rotors on the front for symmetry. (In my letter I said rotor in singular as only one was damaged but, they did replace both in the quote.)

BobnOH · Feb 8, 2019

We love happy endings!
One for us, one for CostCo.
I've had good luck over the years with sending actual mail.

Loose Lugs and aftermath

ratkc135

Veteran Member

BobnOH

not-a-mechanic

Genesis

Top Post Dawg

mk3

Veteran Member

BobnOH

not-a-mechanic

Genesis

Top Post Dawg

Nero Morg

Top Post Dawg

WantingaTDI

Veteran Member

Nero Morg

Top Post Dawg

WantingaTDI

Veteran Member

BobnOH

not-a-mechanic