Should Trailer Suspension Shackle Bolts Be Torqued

Question:

Is there torque specs for bolt size ? Such as 7/8” equalizer bolts and 9/16” hanger bolts

asked by: Scott L

Helpful Expert Reply:

When installing suspension components on your trailer there is not going to be a torque setting for the hanger bolts because they really only get tightened down to hand-tight. Going more than hand-tight can pinch the hangers closed and prevent the suspension from being able to move, which will eliminate the support a suspension provides.

A standard shackle bolt like part # 9163B uses a mechanical lock nut like # TRFA916DLNZ to prevent it from backing off and would need to be tighten until the slack is gone but no further. You could also get a shoulder-style bolt like part # ABS34FR which has a stopping point built in to prevent you from overtightening.

I've attached a short video I made when I was swapping out some leaf springs that goes over each suspension component to help make what I'm saying a bit clearer. If you need help replacing any components of your suspension then let me know and I'd be happy to find the correct replacements.

expert reply by: Kevin C