Over Torqued Wheels?

[TucsonJim]

I'm getting ready to hit the road tomorrow. I am in the process of checking the tire pressure and wheel torque. On my last trip, I checked the wheel torque at 120 ft-lb and none of the lug nuts moved. In the past, I've always noticed a little movement when retorquing. So today I became concerned that my lug nuts may be over torqued. I ran my torque wrench up to 240 ft-lb, and the lug nuts are still rock solid! I'm at the limit of my torque wrench, so there's no way to tell how tightly they are torqued.

Now, what to do? I'm concerned that if I loosen them and properly torque them I could have damaged lug nuts or studs. Should I just leave them alone? I'm also wondering if the torque on the label pasted to the front of the RV is accurate at 120 ft-lb? I have 215/75R17.5 tires, so my wheels are 17.5". According to the Solitude owner's manual, the torque should be 140-170 ft-lb for a 17.5" wheel. Even so, I'm significantly over those numbers.

Any Ideas how I should proceed? Here are some relevant photos:


Owner's Manual Torque Value Table - See 17.5" wheels.


Sticker on front of RV.


Tire and wheel assembly

Jim

[Country Campers]

I would remove one lug nut and inspect the threads on the stud and inside the lug nut. If you have a spare new lug nut I would thread that on the stud to "feel" for fit, too loose is not good. If this looks good remove and retorque all lug nuts. Doing this at home will be much better than out on the road. I would torque to 140, in 3 stages, then check at arrival. I do not think you will see any damage to the studs or lug nuts.

Brian

[Cate&Rob]

Hi Jim,

This is a tough call . . . particularly with your road trip tomorrow . . . I am of half a mind to say “leave them alone.”
Bur, on the other hand, I have removed many many lug nuts over the years that were similarly over torqued by some air gun jockey, and the lugs and nuts were fine.

I would gently remove a couple of widely spaced lug nuts (with as long a breaker bar as you have) and then reinstall these nuts by hand and with your torque wrench to see how they “feel”. If everything seems OK, I would do the rest.

if these are the standard two piece chrome capped lug nuts, the caps are likely damaged so replacement one piece lug nuts would be a good idea as soon as convenient.

Rob

[TucsonJim]

I'll pull one and inspect it. Unfortunately, I don't have a spare to test it. If I see anything amiss with the threads, I'll let you know.

Jim

[howson]

The concern, obviously, is a flat tire necessitating removal on the side of the road. If somethings messed up, that's a bad place for discovery.

Brian's plan sound reasonable.

I wouldn't ignore that "little voice" that's telling you to check what you've found.

[Country Campers]

Thinking a little more, I know I know, you say you "always see a little movement", this is concerning me that you may be unintentionally over torquing the lug nuts yourself, but surely should not reach 240#. Checking torque something that should be done at intervals, which I do a few times a year but not often. After a bearing repack the torque is set then rechecked after first trip then maybe after the next trip. If I see no difference I do not worry about it for the rest of the year. You certainly put way more miles than me.

Brian

[Cate&Rob]

The concern is deeper than just not being able to remove a wheel on the side of the road . . . you can always bring a long breaker bar with you. The question is whether the threads in the nut or on the stud have been damaged. That is a “feel” kind of thing. The nut should thread on smoothly by hand and not be a loose fit. Further is the question of whether the nuts were tightened enough to fracture the stud. This is unlikely and usually happens from the repeated impact of a loose and wobbling wheel.

Rob

[Jlawles2]

If you ran the torque wrench up to 240 ft*lb and it clicked, I suspect the wrench. If by chance it's a click style and not a split beam, leaving it set will cause the spring to get weak leading to under torquing of the studs.

Let's put numbers to it. 240 ft*lb on an 1.5' bar equates to 160 lb of force needed. On a 2' bar 120 lb of force. I'm not a small guy weight wise, but I would definitely know if I was putting that much on a 1.5' or 2' bar.

[TucsonJim]

Thanks all. I removed a couple of nuts and inspected them along with the studs. They look fine. When I was removing them and putting them back on, they felt like they were threading normally and I could turn them by hand with no binding or excessive loose feeling.

Country Campers - When I say I see small movement, here's an example. After torquing the lug nuts on my last trailer (100 ft-lb), I'd check them again in about 25 miles. I'd set the torque wrench at 100 again and I'd notice it move slightly until it clicked. After two or three applications of torque over the next few hundred miles, they would appear to be locked in, and there was no movement before the torque wrench indicated 100 ft-lb. This is what we'd also see in the rocket business.

Jlawles2 - Yeah, it took lots of effort to get a click at 240. It "felt" correct.

Jim

[TucsonJim]

The concern, obviously, is a flat tire necessitating removal on the side of the road. If somethings messed up, that's a bad place for discovery.

Brian's plan sound reasonable.

I wouldn't ignore that "little voice" that's telling you to check what you've found.

That side of the road thingy had me concerned too. When I inspected a couple, they broke loose with my breaker bar. Thanks.

Jim

[Jlawles2]

Jim the only thing I can think is heat soaked studs would have "grown" a bit every time you stopped to check them until they reached a "steady state" of temperature. Once the wheels cooled down, the studs "shrank" thus increasing the clamping force (normally obtained through torque of the nut). Hence the increased torque setting of the nuts.

That's my theory (darn it I forgot to sleep in a Holiday Inn last night). Think of it like setting the preload of wheel bearings to allow for thermal expansion in the system.

[Calbar]

Jim the only thing I can think is heat soaked studs would have "grown" a bit every time you stopped to check them until they reached a "steady state" of temperature. Once the wheels cooled down, the studs "shrank" thus increasing the clamping force (normally obtained through torque of the nut). Hence the increased torque setting of the nuts.

That's my theory (darn it I forgot to sleep in a Holiday Inn last night). Think of it like setting the preload of wheel bearings to allow for thermal expansion in the system.

I always see the same thing that Jim sees. Truck, car, trailer. All torqued and then check torque after some driving and they turn a bit for the next couple of times. Not all of them either but some. I also usually do this check after the truck or car have been sitting overnight. Trailer sometimes at gas stops but usually cold on another day. Guess this is why they always recommend retorquing after some miles.

Rob

[TedS]

The nut conical tapers and wheels conical seats bed in after the vibration of driving. This relaxes the original clamp load. The bolt hole and stud location tolerances guarantee only one nut/hole will exactly match. The rest have some degree of mismatch.

[Scott'n'Wendy]

Imo. Remove and re torque.

[Jlawles2]

I will get roasted for this, but I do run the lug nuts back up with my impact applying approx 50% of the torque (no scientific method just feel) then after setting the wheels on the ground finalize the torque. When I go back and check the torque, I might get a few to give a slight turn.

I also break all the rules and use anti seize on the threads. Not a lot and not the full stud, just a drop. WHY, you pull a lug nut that is rust welded to the stud off in the middle of the night.