What Torque Rating Should be Used to Install Trailer Suspension Shackle Bolts

Updated 02/11/2016 | Published 02/10/2016

Question:

I am replacing suspension on a tandem axle double eye spring trailer. I am having trouble getting the shackle bolts to seat completely, I cannot get the knurls on the shackle bolt completely seated into the shackle link and the bolt head flush. I have been using just hand tools. Is an impact wrench necessary? Thank-you

asked by: Steven G

Expert Reply:

If you are using 9/16 inch shackle bolts which are the most common you will want 65 to 95 foot pounds of torque.

If you are using 1/2 inch then go for 45 to 70 foot pounds. And for 5/8 inch bolts use 100 to 120 foot pounds.

All of these components are designed to move so you don't want to over tighten anything.

expert reply by: Jameson C