SX6 clipped with background


SmithCo’s SX6 Six Axle side dump trailer features three standards axles with three Ridewell steerable lift axle suspensions. The SX6's design allows operators with a standard CDL to haul up to 37.4 tons in a single trailer with easier manueverability, exceptional capacity and less upfront cost than doubles or a train set.

Cylinders are positioned at each end of the tub, rather than in the middle. This allows us to adjust the tub’s position on the frame, optimizing load distribution across the trailer. This flexibility is key to achieving the maximum load capacity. This cylinder design also makes the SX series more durable than other side dump trailers on the market.

The SX6 can comfortably offer a 37.4-ton hauling capacity in a single trailer without exceeding 129,000 GVW rating with the right truck configuration. SmithCo provides custom bridge law drawings to help you choose the right setup for your needs.


  • 37.4 ton haul capacity
  • 40 foot tub length
  • 53 foot frame length
  • Stockpile or windrow
  • Watertight; no leaks
  • Low load height
  • Dumps toward either side
  • 3 fixed axles, 3 steerable axles
  • AR450 Steel Tub, One Piece Floor
  • 80/100 KSI Steel Frames
  • Self-Aligning, Spherical Bearing Hinges
  • External Column Tub Supports
  • No Center Tub Divider
  • Shot Blast Paint Prep
  • Polyurethane Paint


40’ tub26.8 cu yd35.6 cu yd

Model SX6 SmithCo Side Dump Trailer

Specs shown are for 49’ frame length; other configurations available.

Frame Length 53'
Tub Length 40’



8’ 7” at Tub side, 9’ 7” at Center

Tub Construction

1/4" Thick, AR450 Steel (or equivalent)

3/16" Thick, AR450 Steel (or equivalent) is optional

External Column Supports, No Center Tub Divider

Frame Construction 80/100 KSI, Fabricated Steel I-Beam
Kingpin 2" Kingpin, 16" Setting, Replaceable Type
Landing Gear Two Speed, Load Bearing

Push Bar Type, Bolt-On

Cylinders 3500 PSI, 6" bore
Hinges Self-Aligning, Spherical Bearing Type (greaseable)

Air Ride Suspension Standard


(3) 25,000# capacity

(3) 13.2K Air Ride/Lift/Steerable

Hubs 10 Hole, Hub Piloted
ABS 2S1M Anti-Lock Brake System
Drums Outboard Mount, Cast Steel

Steel Disc, 8.25 X 22.5 (12), 9 X 22.5 on Steerable/lift (6)


11 R 22.5 G Radial Tires on Mains 295/75 R 22.5 on Steerable/lift

Brakes 16 1/2" x 7" std, Disc Brakes available
Fenders Front & Rear, 1/4" Synthetic, 7 Degree Slope
Lights 12 Volt LED, ICC w/ Sealed Harness
Mud Flap (4) Polyline Anti-Spray Splash Guard w/SmithCo name

Polyurethane, any combination of gray, white or black

Special colors available upon request

Min. Tractor Hydraulic Reqs.

25-30 GPM

3000 PSI

10 Gallon Reservoir

Layout Options

SX6 Rear View
SX6 5340 L
SX6 53 40

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