Lug nut torque: potential problem?

[Mark]

Short story made rather long:

A few weeks ago I swapped wheels and tires between my two Vibes. The 08 was very noisy but I wanted to try to determine if it was just the tires or possibly a wheel bearing going out. Turns out it was the Big O tires, but now I had a TPMS light on since my sensors were mounted on the 04. I had swapped the wheels from one car to the other same location, but the Goodyear Fuel Max tires that were now on the 08 were due for a rotation so I ran it by Goodyear and had it done.

Today I decided to swap them back, so I pulled one in the garage and backed the other in next to it and got busy. The alloys were going back to the 04 and the steels with the TPMS back to the 08. The steels were showing some rust so I wire brushed and hit them with some flat black Rustoleum, they turned out really good.

The problem I encountered was that the shop guy had way over-torqued the lug nuts, so much so that I couldn't get them broke loose with a 20" star wrench. I ended up using an 18" 1/2" drive breaker bar to get them off, but I also wrenched my back some having to pull so hard. I turned my 1/2" drive torque wrench up to 150 ft/lb and it just clicked when I tried to back them off, so not even sure what they were actually torqued to. The work order says 90 ft/lb but there's no way in hell. If I'd been trying to change a flat along the road I would have had to call a tow truck.

The question I have, after all this bloviating, is should I be worried about the lugs themselves being damaged by the extreme torque? And what about the rotors? I'm making the shop buy me all new lug nuts for about $50, since a few of them jammed in the socket because of the torque being applied. I had to lock the socket in a vise and drive the nut out with a punch. But am I going to have a warped rotor or sheared off lug at some point in the future because of this?

[vibrologist]

That's an interesting question and I wasn't sure how to answer it. I found this here somewhere else:

the same mountainbike Long Lost Magliozzi Brother
July 2010 edited July 2010
Signs of damage from overtorqueing lug nuts include studs that have been slightly stretched at the base threads, deforming them just enough to cause the lug nuts to tighten before providing sufficient pressure to the wheel to properly hold it on the hub. Studs can be checked for thread damage with go-nogo thread gages.

Warpage is also possible. Warpage shows up as pulsating braking.

I doubt if you overtorqued them. "Breakaway" torque, the amount it takes to free the nut, will always be much higher than application torque. 50% higher would not be cause for concern. And 100lb/ft is common spec on many stock applications. 150lb/ft of breakaway torque could easily mean you had in the neighbor hood of 100lb/ft of applied torque. Not a problem.

Actually, it was here:http://community.cartalk.com/discussion ... tor-damage

[Mark]

Thanks for that link, that was very helpful.

Not sure I really buy the 50% breakaway torque theory, at least on nuts that had only been on for a couple hundred miles. Maybe after a few years. But these were way tighter than that even. If he had set them to 90 lbs and breakaway torque was ~145 I don't think I would have to worry about my Craftsman 1/2" drive breaker bar failing. There were a couple nuts where it seemed a toss-up between the nut and the bar breaking first.

I picked up five new nuts from NAPA and replaced all of them on one wheel, when I broke them loose it felt like about the same 76 ft/lbs that I'd put on them an hour or two earlier. I'm going to replace all of them, NAPA will have the other 15 in the morning. After 145k and lots of rotations the old ones are getting a little rounded off anyway. If I replace each nut one at a time I don't think I need to worry about jacking it up or tightening pattern or anything.

[lannvouivre]

First gens have a wheel torque spec of 76 ft-lb. That's the factory spec. 90 is a bit too high. Also, you can indeed damage the rotors by overtightening, but if that's the case, you will be able to feel it as mentioned earlier.

[gtv237]

Damaged rotors are generally caused by uneven torque more than over torque. But it sounds like they just impacted them on. A lot of shops do this every day and never have problems. So unless they are hard coming off, I wouldn't worry about it. Just torque them to a cool 76ft-lbs and be on your way.

[vibenvy]

This is a perfect example of why I do all the tire rotations on our Vibes...

[Mark]

This is a perfect example of why I do all the tire rotations on our Vibes...

I'm probably going to start doing that too, but I haven't figured out how yet. It would be pretty easy to do a front-to-rear same side, but crossing the front makes it harder. I have two floor jacks, so I could raise the front, remove both wheels, then lift the rear one side at a time, cross those to the front and move the fronts straight back.

What rotation pattern do you use? And how do you go about it? What tips and tricks have you developed to make it as quick and simple as possible?

[vibenvy]

I'm probably going to start doing that too, but I haven't figured out how yet. It would be pretty easy to do a front-to-rear same side, but crossing the front makes it harder. I have two floor jacks, so I could raise the front, remove both wheels, then lift the rear one side at a time, cross those to the front and move the fronts straight back.

What rotation pattern do you use? And how do you go about it? What tips and tricks have you developed to make it as quick and simple as possible?

The tires on our Vibes are easy to rotate because they're directional which means they have to stay on the same side, so they only go front to back and back to front, no need for a criss-cross rotation. The all seasons tires we use on our winter wheels are not directional, but I just rotate them front to back and back to front as well. Makes it so much easier. I would recommend getting some jackstands. You can pick up a pair of them for pretty cheap at Walmart. I jack up one corner, remove the wheel, put a jackstand underneath the suspension, let the jack down, jack up the other corner (on the same side), remove the wheel and re-install the opposite wheel, let the jack down, jack up the first corner, pull the jackstand out and re-install the wheel. It's really a simple process to do on your own. I learned how to do it just by watching my dad do it for so many years when I was younger. It's nice because you don't have to worry about some grease monkey teenager impacting your lug nuts on so tight King Kong couldn't get them off. It also gives you a chance to check the tires and see how they're wearing, inspect the brakes, etc. All you need is a jack, 1 or 2 jackstands and a lug wrench (I just use the ones that are in the spare tire well on the Vibes). Be sure to remove and re-install the lug nuts in a criss-cross pattern and re-check them after a hundred miles or so. I have never had an issue with lug nuts coming loose or anything after rotating our tires. Just be careful and take your time. Make sure you are being mindful of what you're doing so you don't hurt yourself or your Vibe. If you need any more tips or anything, let me know.

[vibrologist]

This is a perfect example of why I do all the tire rotations on our Vibes...

My favorite shop uses the torque wrench and they use 2 basic settings: I think it is 85 lbs for steel and 100lbs for alloy. They strongly ask that you return after about 150 miles to re-torque alloy rims. Do you see why this is my favorite shop?

You can't blame a shop for not looking up the specific torque value for each situation. It is taking too much time and makes no money.
http://www.discounttire.com/infoCenter/ ... orque.html" onclick="window.open(this.href);return false;

[vibenvy]

My favorite shop uses the torque wrench and they use 2 basic settings: I think it is 85 lbs for steel and 100lbs for alloy. They strongly ask that you return after about 150 miles to re-torque alloy rims. Do you see why this is my favorite shop?

You can't blame a shop for not looking up the specific torque value for each situation. It is taking too much time and makes no money.
http://www.discounttire.com/infoCenter/ ... orque.html" onclick="window.open(this.href);return false;

Obviously it would take way too much time to check the torque value for each vehicle that comes through. I just prefer to do anything I can myself on our Vibes to save time, money and possible headaches. I don't fault people who take their vehicle to the dealer or a shop for everything, that's just not my cup of tea at this point in time. Doing anything on our Vibes, whether it be detailing them, changing the oil, rotating the tires, etc. is enjoyable for me. I realize it's not that way for everyone.

[ColonelPanic]

I should give up and start doing this myself as well.

The Vibe gets rotations at Costco which hand torques everything to spec. Though when the caliper siezed, one lug nut wouldn't budge and ultimately the stud broke. All the others were perfectly fine. I haven't figured out where the blame lies - was the nut installed incorrectly, or did the intense heat the wheel received from the locked up caliper happen to "weld" it on? I'll reserve judgement and have them try it again.

The Sonic gets rotations at the dealer. What's stopped me from doing this one on my own is that I have yet to invest in a TPMS relearn tool to keep the correct sensor positions on the Sonic. It technically doesn't matter to the car what is where since the car is too cheap to have any sort of pressure display, but the OnStar phone app does. I check the pressures with the app daily (in addition to weekly manual checks) and would rather not have to remember which sensor is where when looking at the app. I thought I could trust the dealer for this trivial task, but they're already breaking off the decorative chrome covers on the lug nuts on that car. They've supposedly ordered one and said they will replace it for me...

[tpollauf]

I should give up and start doing this myself as well.

I'm with you there Although whenever I rotate, or swap summer for winter tires, I am guilty of just "impact wrenching" them on I've been doing this for 30+ years and know when to back off on the tool. Never had a problem to this day. Also, I still use the original CP impact gun AND the air compressor that I bought back in my early 20's, so I know my equipment and it's limits.

[Gandalf]

Well, you just found yet another place where they just use an impact wrench to 'torque' lugnuts. It's really common. I don't let anybody rotate tires, or 'inspect brakes anymore, because of this. I will put marks on the lugnuts with a Sharpie, and if the sharpie marks are scratched, I make them hand torque all the lugnuts.

So many idiots, everywhere. The work order will say 'DO NOT REMOVE WHEELS AND TIRES'. And 'DO NOT CHECK BRAKES'. I generally have to stand outside, and beat the moron with the impact driver over the head with an 18" breaker bar, to keep them from farking up my wheels, studs, lug nuts and rotors. Dipshidiots.

[Mark]

As a follow up to this: this past weekend I was doing some maintenance on my recently acquired used 5th wheel trailer. I was reading in the owner manual that the lug nut torque should be checked/set periodically, recommended torque is 110-120 ft/lb, so I set my wrench to 115 and hit them all. A few moved a bit, most clicked. But then I thought about the fact that the wrench I threw in the camper is a 16" 4-way, and I wasn't able to break my Vibe lug nuts loose with a 20" 4-way.

So, I got the 4-way out of the camper and tried several nuts. All of them broke fairly easily and I re-torqued them back to 115. So how tight, really, were the nuts on the Vibe? If I can break them loose easily with a 16" 4way at 115ft/lb on the camper, but can't budge them with a 20" 4way on the Vibe, what could they have been torqued to? I could barely break them loose with an 18" bar, and deformed most of them just from the amount of torque required. I'm thinking they must have been 180-200 at least, maybe more. I'm 6' 220 lbs, and I had to basically do a one-handed dead lift on my lug nuts. the only way I could generate enough force was to drive with my legs.

The shop swears they only use the impact to remove, and never to install, lug nuts. All lug nuts are spun on by hand and torqued to manufacturer spec. Even though mine were supposedly set to 90, which isn't spec anyway.

[lannvouivre]

I had a flat the other day and couldn't even break the lug nuts loose jumping on the tool that comes with the car. I only weigh about 120 lbs, but still. It was the one time I didn't have my breaker bar in the car.

[Mark]

I rotated the tires on my CR-V today, the dealer apparently torqued them correctly because they broke loose fairly easily. First time I've done it myself, but with two floor jacks and a couple jack stands it was pretty simple and didn't take long at all.

I run Mobil-1 in the CR-V and both Vibes and a 7,500 mile OCI, so from here on out tire rotation will just be part of the routine. Not sure what I'll do about the truck, though. 265/75-17's are heavy sob's.