Retorquing the Lugnuts

Looks like mine will weigh in at 18 lbs (at most with a 12" extension), a little lighter than the average 3 foot sledge hammer (and 9" longer). Guess I could go stand in a hardware store for ten minutes to hold one and see if I faint....

 

I'm also going to try one of these torque adapters to check calibration at the low end of my wrench (between 100 & 145 ft-lb), which should indicate if it's torquing accurately at the high end too. Torque meters cost more than the wrench if you want to test it that high (at 450+). Maybe if I use it a lot I'll go for something with a high range, but by then I'll probably know how much effort it takes to keep from overtorquing at all, if it's off. Says it comes with a certificate of calibration (not all torque wrenches do), as does the adapter, so that should be accurate to begin with. I have a smaller click type for the car, so the adapter is good for checking this also, I've left it set since I had it, not knowing to back it off, but it's at mid range, and possibly still calibrated. Just checked those wheels too, all good, didn't get out of breath.

Guess I'll put a nut and bolt through a piece of wood and lock that in a vice to torque on with this, plus a reducer to half inch socket from the 3/4 drive wrench (or maybe I'll try it on a front wheel, with another adapter back up to 3/4, I might be able to see it there just as well). The clerk at a truck supply place said the trucking company she'd worked at sent out their wrenches for recalibration on a regular basis (possibly because they couldn't test them or had to have that certified), so I think it's worth checking, on the cheap at least (a review for this one said it was tested against high end calibrators and reads accurately, could be, many reviews agree). It's actually meant to convert a standard wrench into a torque wrench, still it's a torque meter all the same.

 

That's fine too, I was only estimating the 10 minutes based on what would be a moderate pace for me. I could just as well say that 15-20 minutes a week is nothing, for what keeps us rolling, with recommended maintenance (per million revolutions, give or take). Good of you to check.

It's all relative, they say a pit stop with five lugs off and on is shooting for 12 seconds, so you're looking at around one minute for an eighteen wheeler (20 vs 100 lugs), or less without removing them (not that it would involve due care for hand torquing), I think they have at least one person on each wheel also. It's possible for one to torque a hundred in a few minutes, if that's their goal and they can run around the truck. I have other things to look at too (and may be doing this in the dark), so whatever it takes. My goal is just to double check.

Well, it may still average out to 10 minutes or less, whether or not I'm always that fast, if I put the torque seal indication on equipment that's most often used, and manually check torque on the rest occasionally. Depends on how well the wrench stays calibrated vs indicators being reliable, as for which I'd want to use the most.

 

Ok tough guy you'll see what I'm talking about how heavy that 18 lbs gets when you're slipping it off and on from inside those duals on a hot summer day. Sometimes with mine the extension will pull out leaving the socket still on the lug. It's nice to have a helper down there, makes it go much quicker. I do my own tire work on my truck and trailer most times without the benefit of a helper.

 

As long as you told me so, I'm okay with that.

 

Another manual I'm looking at from Great Dane Trailers says to check torque every 25,000 miles after initial retorque, which if skipped can result in a loss of half the original (or 250 lb-ft) within 100 miles. At least everyone writing manuals agrees about the initial retorque, not that everyone else does it (or knows to have it checked, I don't recall being told this for roadside tire repairs). They mention tests on new wheel lug nuts. So I'm not sure if older ones reattached onto weathered wheels would lose more or less (well I have those ones to check)...

 

On a similar note, various comments I was reading elsewhere about how static friction relates to torque measurement led me to think a retorque should be done at the high end to 500, instead of starting from 450. The final torque may still be under 500, since part of the torque measurement involves reading static friction to get it turning, if it turns at all, or depending on how little it turns to give a mixed reading, which would be closest to keeping it within 450-500 without breaking it loose first and torquing from scratch to overcome or eliminate friction behind a lower setting. So I'll probably make 500 the baseline for a retorque (and this should cover something looser than 450 + static friction, which is variable, though highest when loosening a wheel nut, and quite possibly within 50 for tightening).

Understanding Wheels and Torque
To get a real indication of how much torque is on the nut, you must get it moving, ignore the high breakaway torque (mostly friction), and then grab an accurate torque reading before you increase the installation torque by turning the nut too far.

Between this and another discussion, I don't know how variable friction is (or no one does for sure), ideally you'd want to loosen the nut and take a new reading with the wrench by retightening without the breakaway torque there.

Can you use a torque wrench to inspect a bolt for proper torque?
In accordance with Bell Helicopter Standard Practice Manual, checking fasteners accurately to determine if they have been tightened to the required Assembly Torque is not possible. When there is doubt as to whether a fastener has been tightened to the correct torque value, the fastener should be backed off from one-half to one full turn and retightened to the correct torque value.

My question about that is, if you have to do a retorque shortly after the initial torque of a wheel, and properly doing this involves reinitializing torque by loosening the nuts, do you have to repeat the retorque after the same distance? It doesn't really add up, as far as manufacturer recommendations go. So yeah, back to 500 as the baseline for tightening, nevermind loosening, I think that'll take care of itself if significantly lower than max torque, when the max is a baseline for clearing breakaway torque, given the nut would be moving by then. At least I'm not likely to overtorque it or leave it vastly undertorqued. If any fasteners were loose prior to the first retorque, another check on those would indicate if that was effective, I think more so than starting the whole process over with loose fasteners all around. Maybe there are degrees of tightness to that within a full turn toward looseness, if it's not the same as several when changing out a wheel, I'd probably try backing them off a turn before retorquing if the nuts were not staying torqued otherwise, and that might overcome their breakaway torque to tighten them in proper range (if max torque didn't get past friction to begin with, presuming they could loosen from there, this sounds half baked though). I don't actually know which is the preferred method for wheels, just that retorquing is, and each could potentially accomplish it. Kind of an order of operations then.

 

wow I can't believe I read this whole thread only thing I can agree with is RC is rite I also do my own tire work and if you think your gonna grab a torque wrench and go around the whole unit and check 100 wheel nuts in 10 or 15 minutes you have never spent any time spinning a wrench if you did it in 30 minutes you will be drawing deep breaths and sweating this I promise

 

Yeah I want to see it done in 10 minutes. And I also want to see just how many pages this thread can go. Haha!!

 

You just saw the guy easily torquing one wheel per minute, yet I'm way out there for drawing that conclusion. Must have been trick photography... time lapse.

Anyway, if overcoming the breaking torque to get a proper reading requires loosening one at time, first the full turn with a breaker bar, and then tightening with a torque wrench, it would take much longer. I don't think it's typically done, but on paper is the correct way of retorquing. Obviously those that he torqued with some movement did go beyond their breaking torque, so just the torque wrench should work well enough at that range.