Sx4 - cropped


SmithCo’s SX4 Four Axle side dump trailer is primarily used in states that allow extended weights and is usually part of a line-haul application.

The SX4-4936 is the most popular length for a four axle trailer. Lift axles and steerable axles are common options to add on this series.


  • 46’ to 50’ foot frame lengths
  • Stockpile or windrow
  • Watertight; no leaks
  • Low load height
  • Dumps toward either side
  • AR400 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


SX Series Tub Capacities

34’ tub23 cu yd31 cu yd
36’ tub24 cu yd32 cu yd

Model SX4-4636 SmithCo Side Dump Trailer

Specs shown are for 46’ frame length; other configurations available.

Frame Length


Tub Length





8’ 7” at Tub side, 9’ 10” at Center

Tub Construction

1/4" Thick, AR400 Steel (or equivalent)

3/16” Thick , AR400 Steel (or equivalent) is optional

External column supports, no center tub divider

Frame Construction 80/100 KSI, Fabricated Steel I-beam
Kingpin 2" Kingpin, 18" Setting, Replaceable Type
Landing Gear Two Speed, Non-Load Bearing

Push Bar Type, Bolt-On

Cylinders 3500 PSI, 5" bore
Hinges Self-Aligning, Spherical Bearing Type (greaseable)
Suspension Air Ride Suspension Standard; Spring Ride Available
Axles (4) 25,000# capacity
Hubs 10 Hole, Hub Piloted
ABS 2S1M Anti-Lock Brake System
Drums Outboard Mount, Cast Steel
Wheels Steel Disc, 8.25 x 22.5 (16)
Tires 11R 22.5 G Radial Tires (16)
Brakes 16 1/2" x 7"
Fenders Front & Rear, 1/4" Synthetic, 7 Degree Slope
Lights 12 Volt ICC w/ Sealed Harness
Mud Flap (2) 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

2,600-2,800 PSI

10 Gallon Reservoir

Layout Options

SX4 Rear View
Model SX4 Rear
SX4 3734
Model SX4 3734
SX4 4636
Model SX4 4636
SX4 4819 DT
Model SX4 4819 DT
SX4 4936
Model SX4 4936