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The HDT-GN 307 is Diamond C’s powerhouse triple-axle tilt trailer. The "307" designation identifies the triple 7,000 lb axle configuration, placing this unit in a 24,000 lb GVWR class. It is the premier choice for operators who need the massive payload of a dual-tandem trailer but prefer the lower deck height, smoother towing, and improved weight distribution of a triple-axle setup.

Triple 7,000 lb Torsion Axles The standout feature is the three 7,000 lb Lippert Torsion axles. Unlike traditional leaf springs, torsion axles provide independent suspension for each wheel.

• The Benefit: This creates a much smoother ride for your equipment, better tracking at highway speeds, and ensures that if you hit a pothole, the shock isn't transferred across the entire frame.

24,000 lb GVWR & Engineered Beam To handle 12 tons of gross weight, Diamond C uses its patented Engineered Beam frame. These beams are custom-fabricated in-house to be taller and stronger at the pivot points while remaining lightweight. This design maximizes your legal payload and prevents the "sagging" common in standard I-beam trailers.

Hydraulically Dampened Gravity Tilt This system uses a heavy-duty cushion cylinder to control the bed’s movement. You simply unlatch the deck and drive your equipment on; the weight of the machine smoothly transitions the bed back to the hauling position. A speed-control valve allows you to adjust the tilt rate based on the weight of your load.

Fleetneck 2.0 Curved Neck The gooseneck features Diamond C's signature curved design. By using a one-piece fabricated neck and eliminating 90-degree corner welds, the design removes the most common stress-fracture points found in traditional goosenecks.

14-Ply All-Steel Radial Tires To support the 24k rating, the 307 comes standard with ST235/80R16 14-ply tires. These are commercial-grade radials designed to handle the heavy vertical loads and the lateral "scrub" that occurs with triple-axle configurations during tight turns.

Full-Width Diamond Plate Neck Box The gooseneck includes a massive storage box integrated between the uprights. It features a gas-shock assisted lid and offers ample room for chains, binders, and tools, keeping your deck clear for cargo.

Warranty 2.0 Every HDT-GN 307 is backed by Diamond C’s updated warranty suite, featuring a 6-year structural warranty, 3-year paint warranty, and a 2-year comprehensive warranty on components. Additionally, the torsion axles carry an industry-leading 11-year axle warranty.

PERFECT FOR
The HDT-GN 307 is ideal for heavy excavation, paving, and agricultural crews. It is specifically designed to haul large skid steers with heavy attachments, mid-sized excavators, and wide-axle tractors. The triple-axle design provides incredible stability at highway speeds and ensures that even if you have a flat tire, you still have four tires on the ground to get safely to the shoulder.

WHY CHOOSE THE HDT-GN 307 OVER THE COMPETITION
The "Triple Torsion" Advantage

While many competitors use triple leaf-spring axles to save cost, Diamond C standardizes Triple 7,000 lb Torsion Axles on the 307.

• The Competition: Uses leaf springs which can lead to "axle hop" and a bouncy ride when empty.

• Diamond C: Torsion axles provide independent suspension for all six wheels. This results in a "velvet" tow, significantly less vibration for your sensitive electronics on heavy machinery, and an industry-leading 11-year axle warranty.

Patented Engineered Beam Frame

Most brands buy "off-the-shelf" I-beams from a steel mill. Diamond C is one of the only manufacturers that fabricates their own beams in-house.

The Competition: Standard I-beams are the same thickness from front to back, adding "dead weight" where it isn't needed.

• Diamond C: The beams are taller and stronger at the critical pivot point of the tilt bed and tapered where they don't need the bulk. This creates a trailer that is stronger yet lighter, allowing you to carry more legal payload than a competitor’s heavier trailer.

Fleetneck 2.0 (Curved Neck Design)

Look at the gooseneck of any other brand: you will see two I-beams welded at a sharp 90-degree angle with a "gusset" plate.

• The Competition: 90-degree welds are the #1 failure point where frames crack under heavy torsion.

• Diamond C: Uses a single-piece, curved engineered neck. By eliminating the corners, they eliminate the stress concentration points. It’s a design borrowed directly from high-end semi-trailers.

Precision Hydraulic Dampening

A 24,000 lb trailer carries massive equipment that can be dangerous if the tilt bed slams down.

• The Competition: Often uses cheap, single-speed cylinders that can "crash" the bed down if the machine isn't perfectly balanced.

• Diamond C: Features a heavy-duty dampening cylinder with an adjustable speed-control valve. This allows you to "dial in" exactly how fast the bed tilts based on the weight of your machine and the outside temperature.

Higher Resale Value (Warranty 2.0)

Because of the brand recognition and the 2026 Warranty 2.0, Diamond C trailers consistently hold the highest resale value in the industry.

• The Advantage: Buyers in the used market look for the 6-year structural warranty and the Engineered Beam stamp. You aren't just buying a trailer; you're buying a liquid asset that will be worth significantly more than a "no-name" brand when it's time to trade in.