Reminder: Check those lug nuts

[theholycow]

Switched to winter tires recently? Rotated tires? Otherwise had lug nuts off? Check them after driving on them!

A week or two ago, 200-500 miles ago, I slapped on my winter wheels (aluminum)/tires. Spec for my car is 80 ft-lb. I used my 80 ft-lb torque stick, which I test against my torque wrench occasionally.

Today I was Just Driving Along at 50mph when the car started going thumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthumpthump like a flat tire, but there was no flat tire. Luckily there was an abandoned church parking lot for me to use immediately. I started by eyeballing suspension and brakes...saw nothing. Jacked up right front. Spun tire, smooth. Rocked for wheel bearing test (recently replaced), no rocking. Jacked up left front...and that's when I noticed the wheel was loose and the lug nuts weren't even.

Since the OEM lug wrench is required for the OEM jack, it was right there with me, but I was bummed that it didn't fit in the recessed lug nut holes in the thick aluminum wheels. Luckily my cross wrench did fit...I'd have needed to call roadside assistance just to come tighten my lug nuts for me if not, and that would probably have taken hours.

I cranked all 20 lug nuts to what I hope was decently even torque all around, and was probably significantly more than 80 ft-lbs. I'll have to re-torque them when I have a chance at home.

So, in summary:
- Check at 50, 100, and 500 miles after lug nuts have been removed and reinstalled (I added the 100 and 500 mile recommendations, but 50 is industry standard).
- If you have different wheels or lug nuts, make sure the lug wrench in your car fits them.
- If your car goes thumpthumpthump, pull over and stop IMMEDIATELY. If I had kept driving on that for a half mile I'd probably have lost the wheel - broken studs, a mangled wheel, and a destroyed brake rotor at the very least.

[Shadow]

Personally, I don't trust torque sticks. I'd much rather take the time to actually use a torque wrench instead. If not, I'll just use my own calibrated arms instead, which have been known to get within 2% of the recommended torque value.

It is good advice to re-torque your lugs after you've driven the vehicle, but in all honesty, I never do that and I've never had a wheel loosen on me. I'm not saying that it can't happen....just that it never has in my entire lifetime. Makes me wonder if your torque stick is the culprit. Maybe your lugs weren't torqued correctly from the beginning.

[bk7794]

I will have to check all mine. I usually just tighten them as tight as I can get them. I don't bother too much with a torque wrench...but now I am a bit worried.

[theholycow]

Do check them but don't worry.

If you're just cranking them down by hand as tight as you can then you're like a whole lot of other cars on the road and they're probably tighter than specified by the manufacturer. I've taken to torquing to spec mainly to avoid potentially warping rotors (an effect for which I've seen good arguments saying it is bunk and saying it is real)...and partially just out of my ever-increasing attempts at doing things as properly as possible.

[six]

It's always a good idea to re-torque after a few drives. When I change/rotate my wheels, I set my torque wrench initially to about 2-3 lb/ft over the recommended torque settings. Then after a few drives, I set my torque wrench to the correct torque settings, and I usually find a few lug nuts that travel a millimeter or two before the wrench clicks, which means that they have significantly loosened, not enough to make a difference, but the fact is they've loosened.

[watkins]

I always torque my own lugs by hand. I go as tight as I can with my cross wrench. I figure if I can get them on by hand, I can get them back off again. Realistically I could just use my impact gun because I know it well enough to torque 85-95lbft consistently.

[DKaz]

Yup, that's why most tire shops tell you to come back to recheck the torque settings. Costco here says 40km, Kal Tire says 100-150km, Cambodian Tire, I mean, Canadian Tire says I don't want to see your face here again. Just kidding, they didn't say anything.

[camera_man]

If I recall correctly, aluminum wheels are prone to greater expansion/contraction due to thermal changes, thereby making the lug nuts more susceptible to loosening.

With that being said, I use my 80 ft-lb torque stick for the initial torque, and then use my torque wrench to get them up to the recommended 100 ft-lb once the wheel has been lowered to the ground. I just don't trust the 100 ft-lb torque stick to provide consistent results (and I like to be thorough with repairs). I then re-check them with the wrench a day or two later (50-100 miles). I usually get one or two that loosened up a bit.

[Shadow]

Yup, that's why most tire shops tell you to come back to recheck the torque settings. Costco here says 40km, Kal Tire says 100-150km, Cambodian Tire, I mean, Canadian Tire says I don't want to see your face here again. Just kidding, they didn't say anything.

I'd guess that less than 1% (probably far less) actually return to any service establishment to have their lug nuts re-torqued. Seriously, I can't ever remember a time when I was wrenching on cars and someone came back to the shop for that.

[DKaz]

I went in back in 2008, but then I got my own torque wrench.

[kamesama980]

Having worked in a shop and used torque sticks for several years, technique using the impact gun has as much an effect on how tight they are as driving style does on fuel economy (holy cow I know you're on Gassavers too). Being the inquisitive person that I am, I started paying attention to how I was torquing lugs down (and oh did I have lots to study). Using my $50 used craftsman impact at ~110psi, one clunk of the hammers in the gun was about 10% under torqued. 2nd clunk of the hammers was close but overtorqued (hand torque wrench didn't move before it clicked and took noticeably more effort to remove). 3rd clunk of the hamers was +50% torque. that's WITH a torque stick! Doesn't really matter if it was 80 ftlb, 100, 120. trucks with 140 ftlb lugs took 2 clunks of the hammer to get to about 98% of desired torque. some of the then-new F150s had larger 21mm nuts and spec'd 150 ftlbs...since we didn't have those torque sticks, I used the 80 ftlb stick and clunked the hammers 2-3x to get them snug...80 ftlb torque stick! What was going through my brain then was to use the torque stick to keep from going over spec while taking advantage of the speed of the impact gun but using the hand torque-wrench to actually to the final tightening.

so yea, torque sticks are sort of a halfway there band-aid to overtightening lugs with an impact gun.they are NOT a substitute for a torque wrench. Whenever I see guys in a shop wailing down for 5-10 seconds on the impact with a torque stick I cringe. Not as much as when every once in a while I see someone using just an impact and bearing down. I think it was for pep boys that I've noticed at the end of hte commercial they show a tech putting on a tire with an impact and socket...no torque stick. to a trained eye you can see he's just acting, not tightening down but still, bad image.

Don't even get me started on anti-sieze...ugh. no, just no.

hehe funny story from back then. I was tightening up the lugs on some old conversion van. The vans owner walks up the the bay door and waves me over. He asks if I can not put the lugs on so tight because he had a hard time getting them off to change out a flat. Monster facepalm ensues.

[theholycow]

Interesting. That differs from my experience with torque sticks. I haven't been using them long and don't trust them so I check against my torque wrench. At first I checked them every time but now I only spot-check them. For me, they have been consistently accurate, never over and only under if I didn't let the hammer clunk a few extra times. I always let the hammer clunk a few extra times. Perhaps old worn-out ones differ from lightly used newer ones?

The anti-seize issue is interesting. On a blog about brake tech, I read an entry titled "Keep Your Studs Clean!: If you don’t, you could lose a wheel!".
http://www.safebraking.com/keep-your-st ... e-a-wheel/

If you apply any friction modifying substance, like oil or anti-seize, to the wheel stud threads, it is going to change the measured torque values. With less friction on the threads, the torque values increase. So, when you tighten a wheel to 85 ft/lbs, it may actually be torqued at 95 ft/lbs (this includes torque wrenches and sticks). The increase in force will mean that the studs will stretch under the increased torque. This stretching can lead to metal fatigue, changes in thread geometry and the possible failure.

The numbers they're talking about are 10%. That's far less than the overtightening done daily with roadside spare tires and novice driveway repairs/rotations. Studs are certainly specified with a lot more margin than that. On the other hand, it might take 150-500% to remove a seized nut. Once I had one that I couldn't budge by jumping up and down on the lug wrench with my entire body weight; I took it to a shop and they took out successively larger impact wrenches until they had a two-handed monster. As far as overtorquing and metal fatigue is concerned, that would seem a much larger worry than 10-20% from anti-seize, and therefore indicates that anti-seize SHOULD be used to prevent fatigue failure in studs.

However, avoiding loosening...that'd be a great reason not to use anti-seize. After reading that and worrying about breaking studs, I decided to go ahead and use it. I suspect that if I hadn't used it then they would have seized, as they always do, and the thermal contraction of those aluminum wheels would have had no effect. I guess seizing is a good thing.

[comingbackdown]

keep-your-studs-clean-if-you-dont-you-could-lose-a-wheel

Let me speak from experience here, kids.
DO NOTput F**KING ANTI-SEIZE on your studs, PERIOD.

[Rope-Pusher]

[quote="camera_man"]If I recall correctly, aluminum wheels are prone to greater expansion/contraction due to thermal changes, thereby making the lug nuts more susceptible to loosening.
Al uminium give me the creeps!


That's why it can cause fars in electrical warren. Prolly also why alloy wheel fat center torque is more likely to drop off.

[Standardshifter]

Usually check after ~50 miles or so.