Good Torque Wrench?
I seem to have galled the lug threads, and destroyed the lug nuts, on my 5th wheel. I have religiously torqued the nuts to 120 ft- lbs as I was told years ago, but seem to have screwed up anyway. Lo...
Forum Discussion
Most times, the specified torque value assumes clean and dry parts. Clean means no dirt, rust, dried-up Âgasket sealer or anything except shiny metal. Some fasteners, like head bolts or main cap bolts, are often specified to be torqued with 30-weight engine oil wetting the threads and washer. If you're installing a fastener that has a dry torque spec, and the threads and bolt face are oiled, you'll need to reduce the torque by 15 to 25 percent, because the slipperier surfaces will decrease friction. Teflon-bearing lubes or moly-sulfide engine assembly lubes can reduce friction enough to require a 50 percent reduction in tightening torque. Even casually substituting a zinc- or cad-plated bolt or washer for an un-plated one calls for, respectively, a 15 or 25 percent reduction in applied torque, because the plating acts as a lubricant. Fail to heed this advice and the fastener will be seriously over tightened.
Aviation maintenance since 1967.
Aviation maintenance since 1967.
