How to Install Tandem Axles on a Trailer

If you recently purchased a tandem axle trailer kit, your first task may be to install the axles to the frame. Tandem or double axle trailers, built for heavy loads, are typically supported by a leaf spring suspension system. Each axle sits across a pair of leaf springs. Two leaf springs, in tandem, are connected across an equalizer bar on either side of the trailer. The equalizer bar distributes weight evenly across adjacent springs, protecting the axles from a disproportionate load weight. Your new axles will be protected from undue wear and tear with a properly installed leaf spring system.

Things You'll Need:

• 4 leaf springs
• 2 equalizer bars
• 6 spring bolts
• 4 U-bolt and retainer bracket kits
• Blocks
• Jack
• Jack stands
• Socket wrench and socket set
• Torque wrench

1. Raise the four corners of the trailer

Raise the four corners of the trailer on blocks.

2. Fasten the center hole of each equalizer bar to the middle hanger on either side

Fasten the center hole of each equalizer bar to the middle hanger on either side of the trailer using spring bolts and a socket wrench.

3. Bolt leaf springs to either side of each equalizer bar

Bolt leaf springs to either side of each equalizer bar using spring bolts and a socket wrench. A leaf spring eye bolt bushing end attaches to a side hole on the equalizer.

4. Set the front axle across the centers of the two front leaf springs

Set the front axle across the centers of the two front leaf springs. Lifting one leaf spring at a time, fasten the free end of each leaf spring to the front hanger bracket using a spring bolt and a socket wrench. The axle should be suspended across the front leaf springs.

5. Fasten the front axle to the front leaf springs using a U-bolt

Fasten the front axle to the front leaf springs using a U-bolt, retainer bracket and a socket wrench. Make sure each end of the axle is sitting in a center leaf spring seat.

6. Set the rear axle across the centers of the two rear leaf springs

Set the rear axle across the centers of the two rear leaf springs. Lifting one spring at a time, fasten the free end of each leaf spring to the rear hanger bracket using a spring bolt and a socket wrench. The rear axle should be suspended across the rear leaf springs.

7. Fasten the rear axle to the rear leaf springs with a U-bolt and retainer bracket

Fasten the rear axle to the rear leaf springs with a U-bolt and retainer bracket, using a socket wrench. The rear axle should be seated at the center of each leaf spring.

8. Tighten all the bolts to the manufacturer’s torque specifications

Tighten all the bolts to the manufacturer’s torque specifications, using a torque wrench. Remove the blocks, and lower the trailer.

Tip

Be sure to check and adjust the axles’ alignment according to manufacturer specifications.

Video: Easiest Way To Install Trailer Hangers on a Tandem Axle Trailer

Comments on this video:

• Excellent video. I really enjoy watching and learning from you. Keep em coming!!!
• Having fabricated for many years, I understand the ease of setup doing it this way. My self I would flip the trailer over for ease of welding and not having to do out of position welds. Thanks for all your interesting content!