What are the Trailer Suspension U-Bolt and Shackle Bolt Torque Specs

Published 07/31/2015

Question:

What should the torque be on my new 4 spring 1750, and u bolts be

asked by: Darrell

Expert Reply:

For trailer suspension u-bolts you can go by the following specs:

1/2" bolts: 45 ft/lbs - 70 ft/lbs
9/16" bolts: 65 ft/lbs - 95 ft/lbs
5/8" bolts: 100 ft/lbs - 120 ft/lbs

For the shackle bolts that hold the spring to the hangers there isn't really a specific torque rating. They have to be snug but the spring still needs to be able to move. I have included a link to our help article on double-eye trailer leaf springs for you as well.

expert reply by: Michael H