Over-torquing trailer wheel nuts?

[fishinhogdaddy]

My Son was pulling his tent trailer back from BC on Sunday when the one side of his trailer collapsed. No injuries but a hard time slowing down and keeping control of the unit at a bad point along HWY#1. After hours of waiting for a tow truck, it finally arrived and the driver remarked that the lug nuts were over-torqued resulting in a couple shearing off and the rest pulling right through the holes of the wheel.
I've never heard of this. I always thought "tighter, is better"?

FHD

[elkhunter11]

Over torquing fasteners, can stretch them beyond the elastic limit, to where they break off under load. Under torquing them can result in some of the nuts coming loose, resulting in too much load on the remaining studs, resulting in them breaking off.

[Drewski Canuck]

Having played with trailer axles since age 16, this sounds pretty funny, and it is third hand now.

A person really needs to see the hub and the rim to know what went on.

You are relying on a tow truck driver for an assessment?

Studs can be pounded out on a normal hub so that they can be changed. The size of the cap and the thickness of the hub plate makes it very unlikely that anything pulled through.

As for over torquing, sure. You can snap a stud if you hit it hard enough with the right impact gun.

All the same, it does make sense to re torque the wheel nuts before a long trip to play it safe. It also is a good idea to check and re pack the bearings, which may have been the source of the shear in the first place if the axle seized.

I lost a wheel in very suspicious circumstances last fall, so I can attest it is no fun. It appeared to be tampered with though as i had drove 20K on those tires prior to the incident.

Drewski

[liar]

over tightening will stretch studs beyond their max stretch and will weaken them and they probably will fail at some point . something else that has been discussed on this forum is lubricating the threads (oil , grease , pipe dope ) . this can make it very easy to over tighten the nuts . torque specs are always for dry threads unless otherwise specified .

tighter is not always better . the proper torque is better ,

[Sooner]

You mention sheared studs. If someone took an impact gun to them, they could have easily stretched the stud. Some of those older tent trailers had dinky little rims for the load and I have seen many of those rims fail at the studs before the studs actually do.


I use an impact to buzz a wheel snug to the hub. Then finish by hand. Glad nothing worse happened to your son.

[ctd]

More then likely a few were under torqued from not being checked regularly. The ones that stayed torqued are the ones that broke off the hub from the weight bearing in them.


It's easy take the nuts that are still attached and find out what their break out torque is that might give you an indication if they were to tight or not.

I miss the right and left hand threaded nuts.

Another thing that happens is people expect to much out of trailers and even their vehicle. They drive to fast, and or over rough terrain usually with to much weight for the trailer.

Just glad he made a safe pullover with out getting hurt. Many do not

[ghostguy6]

Just another quick note. Tire shops generally do not have access to the torque specs for trailers. The general rule was 100 ft/lbs for 12 mm threads and 125 for 14 mm threads, but this often was not the actual specs it required. With trailers I often noticed people would change out a flat for their spare, use the lug wrench to tighten the nut, drop off the damaged tire for repair and leave it at that. Often you cant tell what torque you applied to the nuts. Often people go as tight as they can. Even if you stop to have the torque checked you are already over the limit, unless you specifically ask to have the nuts loosened then re torqued you have stressed the studs.
Also even if you properly torque the wheels every single time you change the tires you should also change the studs out occasionally as general driving causes some stress on the studs. Every time you turn hard, bounce off a curb or pothole you could be adding a sideways stress to the studs.
If your lug nuts seize on your likely applying more stress to remove the nut than it was torqued too. For example let say your torque spec is 100 ft/lbs but the nut is rusted and it takes 150 ft/lbs to remove the nut. If this happens you are actually causing a reverse stretch in the metal which creates an even weaker area than if you had just straight over torqued the nut.

[AndrewM]

I have torqued a lug nut through a boat trailer rim and I wasn't giving it my all by no means. Definitely can happen.

[pgavey]

Saw on the news where someone in BC has been tampering with wheel (loosing off the wheel nuts) there has been a few wheels that has broke free when driving.The RCMP was warning people about it. Maybe they got to your son's trailer also.

[Drewski Canuck]

If your lug nuts seize on your likely applying more stress to remove the nut than it was torqued too. For example let say your torque spec is 100 ft/lbs but the nut is rusted and it takes 150 ft/lbs to remove the nut. If this happens you are actually causing a reverse stretch in the metal which creates an even weaker area than if you had just straight over torqued the nut.[/QUOTE]

Ghostguy6,

You make a very good point here on removal, and the damage it can do.

Alot of those old tent trailers, and we owned a Lionel for 20 years, were made with the cheapest axles you can imagine.

We finally upgraded to a proper 2000# axle due to tube flex, and improper tire wear. The springs were as soft as licorice and the axle had been flexed from bottoming out so it lacked proper camber.

The new hubs were far superior than the OEM hubs as well.

Drewski

[artie]

I did it on a Yamaha quad to lazy to go look up the torque specs so I torqued them to 100 ft/lbs. Driving down the road the wheel started to fall off. Had a look and had lost some of the wheel nuts. Looked up the torque and it was supposed to be only 45 ft/lbs. I guess I stretched the threads and the nuts came loose.

[jstubbs]

Going to agree with Drewski, not sure how a tow truck driver will know for sure that the issue was over-torquing the lugs but that definitely could have been an issue, or one of the issues that compounded into that failure. Could have been crappy lugs, or studs, or ca rappy hub, etc...

Overtorquing lug nuts is definitely not a good idea. Beyond that, makes it a PITA to take off later. Spool lugs on with an impact, but when it comes to tightening, spend the few extra minutes and grab a torque wrench and get then to mfg specs. Painful to watch someone murder their studs by sitting with a finger on the impact going DURRRRR for 15 seconds straight.

[colour86]

over tqing definitely weakens studs as they stretch. My old ford focus had the lugs over tqed at a shop and it ended up shearing 2 of the studs off little under a week later. sounded like a tire blowing out when they let go.

[elkhunter11]

Originally Posted by ctd

More then likely a few were under torqued from not being checked regularly. The ones that stayed torqued are the ones that broke off the hub from the weight bearing in them.


It's easy take the nuts that are still attached and find out what their break out torque is that might give you an indication if they were to tight or not.

I miss the right and left hand threaded nuts.

Another thing that happens is people expect to much out of trailers and even their vehicle. They drive to fast, and or over rough terrain usually with to much weight for the trailer.

Just glad he made a safe pullover with out getting hurt. Many do not

Checking the torque on any remaining nuts likely won't tell you anything, once the first studs broke off, the wheel would have flexed and moved around embedding the remaining nuts into the wheel, resulting in a loss of torque.

[bloopbloob]

Tighter is not always better... We recently had a dual fatality at work due to bolts. (Not lug nuts) but same concept. There is a science behind it. Different grades and different sequences, different torque specs, all need to be followed. Not the type of thing for buddy Joe to wing it.... serious implications when it comes to bolts sometimes. I have a laminated chart of bolt specs on my wall. And make sure you know how a torque wrench works. Had an inspector from Suncor once, who tried using a torque wrench for the first time I assume, and figured if it clicked, it was all good. Turns out many bolts were over 300ftlbs too tight when checked on site. Multi-million dollar screwup. All had to be replaced. 50,000+ 1 1/2" bolts I'd guess

ANYWAYS long story short. When you take something past it's yield strength, even if you don't exceed the tensile strength, you are playing with fire, and asking for trouble. I may know a bit...

[CranePete]

Maybe TireBob could chime in on this.....hello, TireBob?

[ctd]

Originally Posted by elkhunter11

Checking the torque on any remaining nuts likely won't tell you anything, once the first studs broke off, the wheel would have flexed and moved around embedding the remaining nuts into the wheel, resulting in a loss of torque.

It depends on condition of the flange behind the nut. That's where the "might" word comes in to play.
Doing it can be a good indicator if the parts are still together. Depending on conditions.
You can also buy a thread gauge and see if the threads are stretched. On the studs you have. (Use a measuring tape not as accurate or easy).

The rim may have fractured through its use.

Dont let my training in fault diagnostics get in the way of testing faults.

With out pictures of the Hub and wheel were only throwing ideas out anyways.

[32-40win]

I'd call this thread a pretty good illustration of why they say, that if you have one broken stud, change them all. They made Ontario truck drivers responsible for wheel mounting issues, even after just leaving the tire shop. The driver, his problem to deal with the shop afterwards.

[tirebob]

Originally Posted by CranePete

Maybe TireBob could chime in on this.....hello, TireBob?

Everything has pretty much been touched on here. Overtorquing and undertorquing can both create the issues the OP experienced. Honestly though, so could wear and tear on the studs with years of on and off or corrosion or improper components or etc etc, but I suspect it is one of the first two reasons. Depending on the stud size I would not torque above 100 usually on a trailer wheel if it has 12mm studs, but even then that could possibly be too much sometimes. Old Toyota wheel studs back in the 80's would stretch right out even at 80lbs although I have never run into that on a trailer.

We could discuss this until the cows come home but the reality there are many possible circumstances that could have caused the original issue but we don't know the full history of the trailer so it is tough to pinpoint even though logic suggests torque load as the most probable cause.

[elkhunter11]

Originally Posted by ctd

It depends on condition of the flange behind the nut. That's where the "might" word comes in to play.
Doing it can be a good indicator if the parts are still together. Depending on conditions.
You can also buy a thread gauge and see if the threads are stretched. On the studs you have. (Use a measuring tape not as accurate or easy).

The rim may have fractured through its use.

Dont let my training in fault diagnostics get in the way of testing faults.

With out pictures of the Hub and wheel were only throwing ideas out anyways.

In a situation where some studs were broken, and some pulled through, I would remove them all, and check the flange for cracks, and check it for run out, to see if it is bent. Then I would install all new studs, and replace the damaged wheel. That is the way that I, as a red seal millwright would deal with the situation.

[fishinhogdaddy]

Originally Posted by fishinhogdaddy

My Son was pulling his tent trailer back from BC on Sunday when the one side of his trailer collapsed. No injuries but a hard time slowing down and keeping control of the unit at a bad point along HWY#1. After hours of waiting for a tow truck, it finally arrived and the driver remarked that the lug nuts were over-torqued resulting in a couple shearing off and the rest pulling right through the holes of the wheel.
I've never heard of this. I always thought "tighter, is better"?

FHD

Pic of wheel.IMG_2978.JPG

I'd also like to thank those that have replied. There are so many knowledgeable and kind people here on AO that it sure helps to get responses like this to educate those of us not in the know.
Cheers...FHD

[sako1]

Originally Posted by fishinhogdaddy

Pic of wheel.Attachment 155913

I'd also like to thank those that have replied. There are so many knowledgeable and kind people here on AO that it sure helps to get responses like this to educate those of us not in the know.
Cheers...FHD

Under torqued

[tirebob]

Based on that picture it looks like the wheel has been loose for quite a while and rocking around on the hub thrashing everything. Saying it is under-torqued is obvious, but it may have been torqued to spec and the centering hub was not cleaned well or the rim wasn't seating properly and everything settled in a bit further causing the toque load to lessen etc. This is a prime example of why re-torquing of a wheel is necessary, and even better periodic rechecking seasonally etc is a great idea.

[Sooner]

[QUOTE=tirebob;3993934]Based on that picture it looks like the wheel has been loose for quite a while and rocking around on the hub thrashing everything. Saying it is under-torqued is obvious, but it may have been torqued to spec and the centering hub was not cleaned well or the rim wasn't seating properly and everything settled in a bit further causing the toque load to lessen etc. This is a prime example of why re-torquing of a wheel is necessary, and even better periodic rechecking seasonally etc is a great idea.




I think Bob Nailed what happened here. Looks like loose lug nuts. Those stud holes are pounded out.

[ghostguy6]

Definately under torqued. If the nuts were over torqued you would see much rounder holes were the studs would break off cleanly on at least 1 or 2 of the holes before the tire began to wobble which would deform the rest. All the holes being deformed relatively evenly shows the rim began wobbling on the studs before the studs broke and the rim ripped off.

This is exactly why re torqing is necessary after 50 - 100 km and periodic re torques are a good idea.

[nast70]

After a very scary incident a few years ago outside of Hylo, I always check and re-torque the trailer lug nuts. It's quite surprising how often one or two will take a 1/4 turn back to 100lbs.
I bought a CT torque wrench, it stays in the trailer when it goes out. The wheels get checked before we leave, and before we leave on the way back. We do more gravel travel now than in the past, so they do seem to loosen just a hair.
Someone here mentioned tight turns can stretch the studs as well. I live at the end of a cul-de-sac and have to 3 point turn to back into the driveway. Its pretty scary looking at how much the tires fold cutting back. I never thought about changing the studs. We put new boots on her 3 years ago, no new studs then and the as far as I know, they are all original from 2009. I think before hunting season i'll be changing out all the studs.

[ctd]

Originally Posted by elkhunter11

In a situation where some studs were broken, and some pulled through, I would remove them all, and check the flange for cracks, and check it for run out, to see if it is bent. Then I would install all new studs, and replace the damaged wheel. That is the way that I, as a red seal millwright would deal with the situation.

At the very least I would carry out a visual inspection on hub, bearing and spindle. Replace at a minimum the bearings. If not the entire hub assembly.
Doing a indepth job I would also inspect the opposite side for signs of damage and abnormal wear.
Inspect the hangers, frame around the hangers, axle and axle bolts for tightness, cracks or other damage.
These are not heavy duty axles and it does not take much to damage them.

In reality I would cheap out and weight the risk of using it only a few times a year and do the bare minimum.

[TBark]

Same result if a really rookie mistake was made and the cup side of the nuts were out instead of in on the rim.
Don’t ask me how I know, it was 1975.

TBark