LX-450 lug nut torque spec (1 Viewer)

[SpenserAK]

Interesting, thanks for sharing that. Hmm.. although I’m not worried about 110, maybe back off a bit? What are you doing?

 

[Bambusiero]

I've always been curious about the lower, 76 ft-lb, value on the alloys. What would be the downside of higher torque value? Since that type of nut does not apply any wedging forces and is purely compressive, why need for the lower value? Could it be that 76 ft-lb is the reasonable lower limit but higher values would also work? If not, what would be the negative effect of a higher torque value? The studs are the same, so that's not a limiting factor. Could the threads in the shank-style lug nuts be that much weaker (seems unlikely?)

I think the answer to this question is -

The downside of using too high a torque value on the flat-washered type nut would over-stretch the stud, possibly beyond it's yield point, and into plastic deformation, because, as you note, the flat surface, by having the force directly at 90 degrees (normal to - as they say) applies the full force, rather than loosing some to - cosine of an angle less than 90 (wedging force, as you called it).
And then, the flat washer sort of "lubricates" the lug-nut to wheel interface, so that less of the torque is lost to friction there.

So - the torque goes mostly to 2 places (instead of 3):
1) thread surface friction loss.
2) elastic stretching the stud - which is actually the goal of the torquing process.
Well, the actual goal is to clamp the wheel to hub face with sufficient pressure to create enough friction that they don't move around in use.

So - saying it another way - Too high a torque value on that type of nut would work, but too well, stressing the stud beyond it's ability to recover and be used again and again. - just as long as there is enough friction to prevent loosening in use.

And no, I don't think this has to anything to do with the female threads in the shank-style nuts being any weaker - it's all that other stuff.

 

[Bambusiero]

Interesting, thanks for sharing that. Hmm.. although I’m not worried about 110, maybe back off a bit? What are you doing?

Well - yeah - Hmm... here too.
Not crystal clear to me yet either, so my tentative policy for now, reading between the lines - the Gorilla 75-85 guideline is so close to agreement with the Toyota washered shank 76 number...so I'm going with 80, middle of their spec and (don't tell the authorities) I've used that easy to remember number on the Landcruiser forever...5% above spec? pfft - well within instrument error plus component strength margin - Mr T (over)designed it to deal with the real world.
They always come off without any drama, and never loosen or show any bad signs.

But, as I delved into above - am dubious of the idea that - cones is cones is cones - suspect the 109 number is leftover from designs of another era.

But now - this is a new untested deal - Should do a few re-torque checks and look for signs until I gain confidence...
And - been meaning to call Gorilla and ask...

 

[BILT4ME]

Well - yeah - Hmm... here too.
Not crystal clear to me yet either, so my tentative policy for now, reading between the lines - the Gorilla 75-85 guideline is so close to agreement with the Toyota washered shank 76 number...so I'm going with 80, middle of their spec and (don't tell the authorities) I've used that easy to remember number on the Landcruiser forever...5% above spec? pfft - well within instrument error plus component strength margin - Mr T (over)designed it to deal with the real world.
They always come off without any drama, and never loosen or show any bad signs.

But, as I delved into above - am dubious of the idea that - cones is cones is cones - suspect the 109 number is leftover from designs of another era.

But now - this is a new untested deal - Should do a few re-torque checks and look for signs until I gain confidence...
And - been meaning to call Gorilla and ask...

Also, the shank style wheels are HUB centric so the "weight bearing" of the wheel is on the center of the wheel to hub instead of on the actual lugs. The lugs only clamp the wheel to the surface to resist side forces.

The cone (acorn style) are LUG-centric so the weight bearing and all forces are on the lug nut to wheel interface.

 

[Bambusiero]

...the shank style wheels are HUB centric...
The cone (acorn style) are LUG-centric...

Not all is so black & white however.
My newly installed FN-Wheels Six-Shooter 17x8xET0 wheels were bored through to 106.2mm to be hub centric, at nominal extra cost.
And yet - held on by conical seat acorn style lug nuts - a bit of both types here now.

 

[SpenserAK]

Feel like I read it somewhere here that the OEM wheels are considered both hub and lug centric, or at least some of them? I had 2 each conical & shank, and each style wheel sat properly on the hub for the nuts to go right in. Conical obviously seats the wheel on its own, and I feel like these shanks do the same when they go through the hole, but don’t quote me on that.

My FNs are Toyota hub centric, and also conical. It all works either way, just need to use the right nuts, obviously.

Edit: Rotated today. These FNs are clearly hub centric to start - they fit like a snug glove over the hub with zero slop, while the stockers went on easier, but still lined up the lugs.