Re-Torquing Lug Nuts

[1st John]

Airstream Flying Cloud Owners: My intent is to explain the reason (wisdom from experience) for torqueing wheel lug nuts. First, we are told to re-torque our wheel lug nuts on 1) a new trailer, 2) after replacing a wheel from changing a flat tire, and 3) after replacing a wheel from replacing a worn-out tire. The stated interval is at 5, 25, and 50 miles; before every trip thereafter; and following winter storage before beginning a trip (Flying Stream Flying Cloud Owners, “Wheel separation can occur,” page 8-5). The Maintenance Schedule table, “Every 5,000 miles or 90 days,” also states “Torque Wheel Lug Nuts,” page 8-2.

The reason for these stated intervals is that trailer weight and road conditions can cause the wheel lug nuts to loosen over time. This became clearly evident to me as a young Lieutenant assigned to an Army Heavy Truck Company. After every trip hauling heavy tanks and other tracked vehicles, our drivers were required to re-torque their trailer wheel lug nuts (four sets of duals on each side of the trailer). If the nuts became loose, the studs would break. In three years with the unit, I witnessed two incidents where drivers failed to re-torque their trailer wheel lug nuts – and a dual wheel snapped its studs and separated the wheel assembly separated from the trailer.

Bottom line: do it according to the recommended maintenance schedule, not only for your trailer but also for your tow vehicle!

[ROBERT CROSS]

Describe 're-torquing'.
To torque a fitting you torque to a specific number.
To re-torque you loosen and do it over again.

I torque once, check tightness before every outing, and make sure the threads are clean and dry, (no lube) I remove the wheels every Winter.

POI... 38yrs and I've never found a loose lugnut.👍


Bob
🇺🇸

[CharlesinGA]

I recheck torque by putting the torque wrench on the lug nut and pulling till it clicks. If it don't move or moves a tiny bit its OK, I've never had a loose one, and never found one loose after that. Alloy wheels do tend to need the torque check more than steel wheels, as the softer metal gives and the lugs are left loose, sorta.

I've never seen a wheel get loose or break studs on any vehicle I own.

Charles

[Redbarron55]

If you are going to be AR about the torque of the lug nuts you need to back them off and then retorque as to actually torque them they need to be moving as they reach the required torque otherwise you are just verifying that they will not break loose and move with the applied torque.
H have steel wheels on my 1985 Sovereign and steel wheels are made with torque holding preloading and retaining forms stamped into the hub.
Aluminum wheels do not have this feature and the rear mounting surface is (should be) flat. Some still have machining marks that will flatten out with time and "wear" if the wheel can move in relation to the hub.
Aluminum wheels do need to be retorques more often due to the changes in temperature and the possibility of fretting.
Best to follow the recommendations of the manufacturer in any case.

[richard5933]

Originally Posted by CharlesinGA

I recheck torque by putting the torque wrench on the lug nut and pulling till it clicks. If it don't move or moves a tiny bit its OK, I've never had a loose one, and never found one loose after that. Alloy wheels do tend to need the torque check more than steel wheels, as the softer metal gives and the lugs are left loose, sorta.

I've never seen a wheel get loose or break studs on any vehicle I own.

Charles

Putting the torque wrench on the nut and turning till it clicks will not do the job here and can actually mask a poorly-torqued nut.

Here's why...

When the nut is torqued to the proper setting, the metal in the stud & nut are slightly stretched and deformed - not enough to do damage but enough to help hold them in place.

If a loose nut has enough time, corrosion can form on the threads. This corrosion can cause the nut to stick to the stud enough so that the torque wrench reads it as the correct torque.

The only way to know for sure that the proper torque is there is to loosen and re-torque them.

On electrical devices such as a transfer switch there are also torque settings for the terminals. On my vintage motorhome I was having trouble with the voltage readings and suspected loose connections. Strangely, the terminal screws all had what appeared to be the proper torque on first inspection, but the cables just didn't feel right or like they were fully tightened in place. What I found after pulling out the set screws was that there was enough corrosion on the brass screws to make them extremely difficult to turn, but since the copper cables had become so fully compressed behind them the cables were actually loose. It wasn't until I loosened and then retorqued them that the cables finally felt right and the voltage problems returned.

Long story short, best practice on re-torquing is to first loosen and then re-torque. Even better is to clean the studs between the two steps.

[waninae39]

its best to re-torque all wheels at the beginning of each season and then on some regular interval.

there is no exact interval as it has many factors,

• how bumpy the roads are,
• do you go off road ,
• how often is the AS not moving ,
• how old are the tires,
• how old are the wheels,
• how many time have they been taken off the AS,
• etc
  

as wheel have a TPMS that can measure the temp and pressure in each wheels, set a good threshold , then if one is exceeded, you will know that something is wrong

safety and good habits are cheap insurance for you and your families

[Wayne&Sam]

If a wheel has been removed, I check the torque at 25ish and 50ish miles. I do find one or two lug nuts on a wheel can take another click from time to time. At 50, rarely. I don't check again if there's no movement after that.

I also do check at the start of the season.

[Al and Missy]

Originally Posted by Redbarron55

If you are going to be AR about the torque of the lug nuts you need to back them off and then retorque as to actually torque them they need to be moving as they reach the required torque otherwise you are just verifying that they will not break loose and move with the applied torque.
H have steel wheels on my 1985 Sovereign and steel wheels are made with torque holding preloading and retaining forms stamped into the hub.
Aluminum wheels do not have this feature and the rear mounting surface is (should be) flat. Some still have machining marks that will flatten out with time and "wear" if the wheel can move in relation to the hub.
Aluminum wheels do need to be retorques more often due to the changes in temperature and the possibility of fretting.
Best to follow the recommendations of the manufacturer in any case.

Admittedly not an expert in these matters, but why wouldn't the loosen and re torque guideline apply every time you re-torque the wheels? Lets say I torque the wheels and the guideline is to re-torque them after 50, 75, and 100 miles. How would I ever get past re-torquing them at 50 miles?

[richard5933]

Originally Posted by Al and Missy

Admittedly not an expert in these matters, but why wouldn't the loosen and re torque guideline apply every time you re-torque the wheels? Lets say I torque the wheels and the guideline is to re-torque them after 50, 75, and 100 miles. How would I ever get past re-torquing them at 50 miles?

I'm also not an expert, but here's my thinking on this...

The reason that I loosen and then re-torque is that after some time corrosion can build up between the stud and the lug nut resulting in a false torque reading. So if the wheel's been in place for a season, I'll go through the entire procedure.

But, when the tires are first mounted I just recheck the torque by putting on the torque wrench and seeing if it clicks. This is done usually at the first & second stops after mounting a tire. Since a wheel may not have been properly seated against the hub when initially mounting, this quick check-up is my way to know that things were done correctly.

To me there is a difference between 're-torquing' the lug nuts and 'checking' the torque. One is done after a chunk of time & driving, and the other done pretty soon after the initial torquing to assure that the wheel is properly seated on the hub and torqued to spec.

[Wayne&Sam]

Originally Posted by Al and Missy

Admittedly not an expert in these matters, but why wouldn't the loosen and re torque guideline apply every time you re-torque the wheels? Let's say I torque the wheels and the guideline is to re-torque them after 50, 75, and 100 miles. How would I ever get past re-torquing them at 50 miles?

My thoughts exactly. There is a difference between the theoretical and the real life situation.

My 20 year experience tells me (maybe not you) that once a lug nut is seated and secure, it stays that way.

We travel from NY to MT every year. If I stopped every 50 miles and loosened and then retorqued the lug nuts, I'd still be on our first trip.

[ROBERT CROSS]

I mentioned in my post that I remove my AS's wheels for Winter storage and rotation.
We also rotate the tires on our TV & DD.
I recommend that everyone remove, inspect, clean, and rotate the AS's at least once a year.
It's also important that the stud threads be clean & dry without any lubricant for an accurate torque reading, friction=torque.

Bob
🇺🇸

[OneToFixIt]

Wow! Anyone worried about threads being damaged or worn out by excessive loosening and retorquing?

Logically, does anyone believe all the millions of people driving on the roads are all retorquing their lug nuts all the time? Impossible.

So why don’t we pass vehicles with broken off wheels everyday?

[rheston1947]

This is a really nice summary and good to have it online as a "refresher."

I have a 2019 Classic. I check the torque at the beginning of each travel season and before and after each trip.

I do this because many of the routes I travel, such as around Denver, CO or through the mountains the roads, can be really atrocious and I have found a lug or two that go a click or two on the torque wrench.

I've been fortunate with the tow vehicle that there's been no "play" in the lugs.

As a 31 year service vet I really appreciate the reminder and your citing what we're taught on active duty.

[SunchaserV]

Originally Posted by OneToFixIt

Wow! Anyone worried about threads being damaged or worn out by excessive loosening and retorquing?

Logically, does anyone believe all the millions of people driving on the roads are all retorquing their lug nuts all the time? Impossible.

So why don’t we pass vehicles with broken off wheels everyday?

Good point.

For the truly concerned, do what the big boys do - buy a correctly standardized air impact wrench. You can check all your nuts in about one minute. Just be sure you know the appropriate torque for your nuts but more importantly the thread bolt attached to the axle drum.

Once correctly torqued (hopefully not stretched too much) overdoing this procedure weakens the bolt. I've worked in industries where the proper torque applied necessitates throwing the nut and bolt away before the next use.

[NutmegsCamper]

Originally Posted by SunchaserV

.
I've worked in industries where the proper torque applied necessitates throwing the nut and bolt away before the next use.

This is another good point, especially with safety items. Any time the bolts that hold car seats and / or seatbelts in place are loosened / re-torqued, they are supposed to be replaced (At least as called out in the last 3 Ford trucks I've owned.)

[KK4YZ]

Originally Posted by Wayne&Sam

My thoughts exactly. There is a difference between the theoretical and the real life situation.

My 20 year experience tells me (maybe not you) that once a lug nut is seated and secure, it stays that way.

We travel from NY to MT every year. If I stopped every 50 miles and loosened and then retorqued the lug nuts, I'd still be on our first trip.

The 25, 50 mile, etc guidance is only the FIRST few miles after having remounted a wheel. I notice that after remounting I will get some movement in many of the lug nuts upon tightening. After the next interval the amount of movement will decrease or be nonexistent. When the torque wrench clicks without any lug nut movement I know I’m finished with it and can roll on down the road.

[sfranklin]

Originally Posted by ROBERT CROSS

POI... 38yrs and I've never found a loose lugnut.👍


Bob
🇺🇸

In addition to the loose lug nut in my head. I regularly break out the torque wrench and check the torque. If the bolt starts to back out, which can happen frequently on alum rims compared to steel rims, it re-torques the lug nut. If the nut is already at the setting, my torque wrench just clicks.

I have have not seen any wide changes, but I have had some that were not up to torque rating, some a bit more than just not up to torque ratings.

I had a friend tow his AS in the hills, didn't check his trucks rims ever, they were alum, one rim ripped off while towing. Besides a bruised ego, no loss of life and minimal damages....so yes, check your torque on the lugs as recommended.

[SunchaserV]

Originally Posted by KK4YZ

The 25, 50 mile, etc guidance is only the FIRST few miles after having remounted a wheel. I notice that after remounting I will get some movement in many of the lug nuts upon tightening. After the next interval the amount of movement will decrease or be nonexistent. When the torque wrench clicks without any lug nut movement I know I’m finished with it and can roll on down the road.

Just curious, whose "guidance" and why? Improper torque specs, defective nuts or bolts concerns by the axle manufacturer?

Isn't this type of "guidance" uncommon outside the AS world? IE, the tens millions of cars, light trucks, SUVs and other vehicles.

Or, a non calibrated non-repeatable torque wrench maybe?

[Dan Jam]

Torque is a twisting motion used to stretch the bold/stud. The stud is made longer and tries to go back to its original shape (length) creating a spring like clamping force. Like a guitar steel string you need to check the stretch regularly due to use forces to ensure it has the right stretch (torque).

[uncle_bob]

Hi

If you ask the AS folks at JC about "how?", their answer is to use the "put the wrench on it and hear it click" approach. They do not recommend the back it off every time method. One gentleman who answered that question claimed to be involved in putting the requirement to re-torque in the manuals.

What that all means ... I have no idea.

Bob