Originally Posted by Pat.Mann
Our Equalizer hitch on Sequoia towing 27FB failed within 1 year with major weld breaks - didn't drop anything, but we felt (dealer concurred) we had to replace it because it looked like it was likely to physically come apart. Not aware of anything that would have caused the failure, no warning, just happened to inspect the hitch during hitch-up and notice the weld breaks. Discovered over Xmas-New Years when factory was closed and no interaction possible, had to replace entire assembly at dealer instead of just the main linkage part, over $1,000 to replace including labor to get back on the road.
Have not communicated with factory or sent hitch back for warranty yet because we are on the road and won't be back at base until mid-April.
Our torque wrench tops at 150 ft-lbs, so we don't have capability to check the high torque on some of the hitch bolts (>300 ft-lbs) so can't do that ourselves. Hitch has seemed to work well, replacement is fine so far; don't know why this occurred.
Don't know about the welds breaking, but a bolt can fail from a fatigue break if not tightened properly. (Once had a Husky weld fail on me, warranty replaced.)
If the required bolt torque, is higher than your wrench's range, use a lubricant on both the threads and the face of the nut, and reduce the torque by amounts as below:
-oil, reduce by 20%.
-bearing grease, 30-35%
-Extreme pressure lube such as C-5 colloidal copper, 'Never Seize' or similar, reduce torque by 40%
This will give you about the same bolt tension as dry-torqueing. Why?
(I like the C-5, myself.)
Only 10% of the applied torque is used to actually tighten the bolt; the rest is to overcome friction; 40% on the nut face, 50% on the threads..
BTW Do NOT use dry torques on lubricated bolts; you will pull the thing apart, or strip the threads.
(Source: Premier Fastener Corp. I was once an agent there, in Canada)
One good place to use this information is in tightening the ball on the head.
Many 2-5/8" balls, have 1-1/4" shanks that call for 450 ft. lbs.
My torque wrench only goes to 250, well short of it. So.........
I calculated that 40% of 450=270 ft. lbs., a tad short of the requirement; but at that figure, that ball 'ain't' going nowhere.
(I needed to sit on the ground, with my foot against the rear bumper, to react against me sliding under the Ford, when I pulled that high a torque.)