Hanger Kit, U-Bolt Kit and Spring Seats for Tandem Axle Trailer with 3-1/2 Inch Diameter Round Axles

Question:

I bought a home made trailer that has the axles welded straight to the frame. I am going to install a tandem axle hanger kit and springs underneath it. The axles are 3.5 inch tube diameter. I will be towing a asphalt sealcoat tank so I want the lowest trailer height possible without sacrificing suspension function. I was thinking about going with the apt 3. With the short front hangers be ok for the suspension and mount the axles on top of the springs or go with the apt 9. Tank with weigh 4,000 lbs and have liquid in it.

asked by: Matthew H

Expert Reply:

A 3-1/2 inch diameter round axle is usually rated at 8,000 pounds but could also be a 3,500 pound axle though this is rare. You can get a more accurate determination of the capacity by getting the inner and outer bearing numbers stamped into the sides of the bearings.

For a hanger kit # APT3 will keep the distance from the deck to the axles at a minimum and still have room for suspension travel. You will also need a u-bolt kit, # APUBR-35, for one axle. And you will likely need new spring seats, # TRSS350, for one. You would need a total of 4 for tandem axle trailers.

expert reply by: Michael H