Re: [DML] Re: Tire torque settings

["B Benson" <delornut@xxxx>]

 An interesting fact regarding the torque sequence involves something called
torque recovery. We use computerized electric 5 spindle wheel nut guns to
attach the Ranger wheels in our plant. All five nuts are run down to 130nm,
then the tool waits momentarily, then re-torques them in the torque recovery
mode. Obviously all 5 lugs won't reach torque at the same moment during the
initial rundown. The first lugs that reach torque (130nm in our case) will
relax to considerably less (as much as 20%) as some of the others reach
torque. For that reason we need the recovery mode to assure they are all
properly torqued. When tightening the DeLorean wheel lugs the proper method
would be to work your way across the wheel and tighten opposite lugs and
then return after the initial tightening to re-torque them all. This hold
true with any wheel installation and when I see the tire shops use their
impact guns I feel like throwing up.

Bruce Benson


> One of my father's old SAE mechanic's books tells of a test (probably done
> by a tool manufacturer) where 20 mechanics, each with 10+ years of
> experience, were asked to tighten a nut down to about 50 ft-lbs of torque.
> None of them were able to get within 25% or something like that with any
> regularity. And these were professional mechanics. The moral of the
story
> is, don't try to "feel" torque settings.
> --Rob Hook