Tighten wheel lug nuts
On a steel one piece rim for a heavy duty truck, is there a rule of thumb for tightening the lug nut that involves noting 'the turn'?
My truck is a bobtail dump with Accuride one piece steel rims, tires are 10R-22.5.
I remove the wheels using a one inch impact with a 'truck wheel' socket, in a a little bit of a time staggered pattern so the last one is not fully tight by itself.
When reinstalling, after cleaning the threads with a wire brush and the mating surfaces, I tighten the nuts by hand using a 3/4 breaker bar with moderate force so I can feel they are seated evenly. This is done using the cross wheel pattern like a star in a couple steps.
One or two small drops of 30w oil on the threads, no oil at all on the contact point where the nut touches the rim. We have minimal corrosion problems: no snow, little rain.
Other than using a torque wrench as is popular now, what was/is the rule of thumb for the number of turns expressed in flats (eg 2 flats is one third a turn, 3 flats is one half a turn).
The turn of the nut method is used by ironworkers to establish preload on structural steel bolts, but those charts are for flat face nuts with different diameters and thread pitch, so I figured truckers would have an answer for how to do these wheels in a similar fashion when a torque wrench is not available.
First(and foremost)NEVER use oil on threads-PERIOD!!! Anti-seize is acceptable on stud piloted , but only recommended to be used on the outside of the barrel nuts in a dual application. Second,are they stud piloted or hub piloted wheels?On hub piloted wheels, you are actually supposed to put a few drops of oil on the nuts between the nut and washer to lube as they are turning against each other-but not on the threads. Anyways,most guys think "hammer 'em"'til they won't turn anymore, which is wrong-especially with a one inch drive gun. Inch drive impacts are capable of 1100-1500 ft/lbs(depending on the brand). You want around 450. Never heard of a rule of thumb relating to "the turn", mainly because few if any guys do them by hand.On stud piloted wheels it's easy to tell when they've been over tightened, because the lips of the stud holes will be ruined.(Picture the nut being driven through the wheel) There is a 1/8th inch lip between the front and back of the holes.If it's not there, they've been over-torqued and not useable.I suggest using the gun and getting a feel for it,keeping the volume and pressure of your supply the same is the only way to get a feel for it.Snug them all, then bump each one a few hammers of the gun and check with a torque wrench to get the feel down is the best advice I can give you short of using the torque wrench every time.
Last edited by tireman; 09-03-2012 at 12:34 AM.
Sorry, forgot to indicate: these are stud piloted. It appears no one has overtightened them (thank goodness) as the fasteners and the rims appear to be 'as built' as opposed to 'as destroyed'. The mating parts are not ovalled.
The philosophy of "hammering till they don't turn" had me worried as the one inch impact gun is quite capable of making a mess.
Since my post, I received a recommendation/suggestion to investigate 1/2 turn (three flats) from hand tight by comparing torque wrench 'how many flats' &/or man's weight on a three to four foot wrench extender to discern...
The wrenches we use on red iron are always marked with colored lines to make it easy to remember how many flats - we are in the habit of watching the socket turn. FYI as an side, the building business is moving to a torque control fastener which the special wrench handles both and all the torque and countertorque, but please note these fasteners are installed once for the life of the connection.
Here's a pdf on 'turn of nut' - notice the amount varies as the length to account for more stretch I guess
Here's a site that shows a torque control fastener
What happens if a token miniscule amount of oil is used on threads in lieu of anti-seize?
Use a torque wrench, it is the only acceptable way of tightening them properly
Also go to Accuride website, all your info is there.
Last edited by miro; 09-03-2012 at 10:06 AM.
If you are going to use some sort of anti seize product, spend a few dollars on the correct stuff for your application.
Sure our conditions are not as harsh but I have never used any sort of stuff on wheel bolts/buts.
Also the general rule is to tighten the nuts as much as you can by hand with a 4 to 5 foot bar, in other words if you put a 100 pounds of pressure on the end of a 5 foot bar you have 500ft/lbs of pressure.
That's why I like the foot/pounds measurement system, easy to work out.
Remember you might have to change a wheel on the side of the road and if it is over tightened you will have trouble undoing the nuts.
It is also a good idea to put the spanner over the nuts, at least once a week, more so if a wheel has recently been fitted. This is particularly important on spider wheels.
That's good advice if you have a fleet of trucks and a workshop but your average truckie is not likely to carry a 3/4 drive torque wrench.
Originally Posted by miro
Do you just keep tightening them every week? Mine start making that screaming sound, is that tight enough or do you keep going after that?
Originally Posted by Hendrik
Like I said, you want about a 100 lbs of pressure on the end of a 5 foot bar or in metric speak about 50 kgs at 1.5 metres. That screaming sound is dry metal on metal and quite normal.
This is good advice.
Originally Posted by tireman
We always just hit them with a 3/4 gun or bar and pipe and never thought any more about it. Until one operator changed a flat and a week later a wheel passed him going down a hill. Of course it wasn't long before the safety gurus decided that from now on ALL wheel nuts WILL be tensioned with a tension wrench. The upside is that I was shocked to find how much we were overtightening everthing previously. As it turns out our Wurth rattle gun was easily hitting 750 ft/lbs and even the bar and pipe method of " pretty tight and just a little bit more was way too much. We have mostly Japanese trucks which call for 500 to550 ft/lbs. Not everyone can afford a professional torque wrench but it would be a good idea to get a feel for what the correct tension feels like. It certainly put a change in my thinking.
I think calling that person an operator is an insult to proper operators, wheels coming lose is down to not checking the wheel nuts, which is a daily visual inspection and quick feel. On spider hubs you can give the wedges a tap with the tire beater to make sure they are tight.
Originally Posted by spanner
It amazes me that some people can just live in their own little dream world and not look after the equipment they claim to know how to operate. Checking the tires is one of the most important roles of a truck driver and that person is lucky the tire didn't hit someone.
We had this once on a harvester, had a flat, put on the spare and told the 'driver' to check the nuts at the end of the run and keep checking them every now and then, half hour later the wheel was just about off the hub and only two wheel nuts where left. Asked the fella if he had checked the nuts, reply was "yeah I looked at them", didn't know whether to laugh cry or just beat him for a while with the 3/4 drive bar. Lazy so and so.
Here lately the commercial operations have brightly colored what look like plastic tabs between the wheel and lug nut. Once all nuts are torqued properly all the tabs point in the same direction making it a simple task while walking the rig during pre-flight to confirm all is "tight and right" with the lug nuts. I'm not a Driver but from what I've seen and having spoken to a few they all seem to like this system. Surely beats having a wheel & tire combo pass you by on the highway.......oops!
"An Operator is what an Operator does, always safe, continuously honing their skills not to become, a once was"
Why no oil? Antisieze affects the torque spec more than oil.
Oil is a lubricant that can cause your nuts to come loose, even if torqued up properly.
Originally Posted by PhilDirt
It's the friction of dry metal on dry metal that keeps your nuts on.
I have seen those pointy wheel nut indicator thingys, probably a good thing in a situation where you have multiple drivers for one truck but a pro driver would be embarrassed to be seen with those on the big chrome beasty.
A pro driver would not have them on "the big chrome beasty"-period. Those things are on local vehicles-public transit buses, school buses,and refuse trucks are about all I've seen them on-oh, and municipality trucks. Anti-sieze is made to prevent corrosion.Other than trailers going onto ocean going ships, the only place I'd use the stuff is the outside of the barrel nuts when you have an aluminum wheel involved and no zinc ring. Oil is not only a lubricant, but it's use leaves a film that attracts any and everything to it, which in turn will gum up the threads with all types of gunk. Best of luck removing those lug nuts,let alone using them again. Oh, by the way-it's the clamping force that keeps things together, which does require some friction. THEORETICALLY-you could use plastic studs and nuts on hub piloted wheels if you could generate enough clamping force with them, because of coarse the weight is carried by the center of the wheel riding on the pilot pads.
Last edited by tireman; 09-06-2012 at 07:55 AM.