Determining Proper Suspension Bolt Installation

Updated 04/18/2018 | Published 04/16/2018

Question:

I have a kaufman trailer that is less than a year old and I have already had to replace the 10K spring bushings. How tight should the bolt be tightened?

asked by: John A

Expert Reply:

Suspension bolts should be as tight as possible WITHOUT restricting motion of the leaf spring or related parts. There is not a specific torque rating.

The first thing you should make sure of is that the bolts you have are long enough so that when installed you will have at least 2 threads protruding from the nut.

Next, make sure that the nut you are using is a locking type so that it cannot work loose and fall off.

Next, if the bolt you are using has knurls at the bolt head you will want to tighten the bolt down until the knurls go through the shackle link or spring/equalizer hanger and the bolt head is flush. Then, back off the nut just a bit so that all of the components are pulled together but not so tight they cannot move with a bit of force.

expert reply by: Adam R