Medium Duty 337

The Peterbilt 337 is a Class 7 medium-duty truck, positioned as a premium option in Peterbilt’s vocational and regional haul lineup. Built on the same durable platform as the 325, 330, and 335, the 337 is known for combining rugged capability with a refined cab experience—ideal for fleets and owner-operators seeking a professional image with real-world versatility.

The 337 is commonly used for:

• Rollback and towing
• Refrigerated and box delivery
• Dump and construction material hauling
• Utility and service trucks
• Fuel, lube, or vacuum tankers
• Emergency vehicles or municipal fleets

With a GVWR rating up to ~33,000 lbs, the 337 is capable of handling heavier payloads while remaining maneuverable in tight delivery zones.

Cab Type:

Like the 325–335 models, the Peterbilt 337 uses the 1.9-meter narrow cab. While narrower than the 2.1m highway models, it still supports a comfortable work environment and is available with options like a high-back seat, tilt steering, and air ride suspension.

Aftermarket Seat Compatibility:

The 337’s 1.9-meter cab uses the standard vocational bolt pattern—typically 4.68" x 12"—which supports a wide variety of aftermarket seating options, especially those designed for vocational or medium-duty applications.

Popular aftermarket seats for the 337:

• Knoedler Harrier – low-profile option, ideal for narrow cabs and tight vertical space
• National Ensign or Corsair – direct bolt-in fitment for many models
• Bostrom T-Series or Wide Ride Core – may require a low-profile base

Installation Notes:

• Most seats will bolt in directly
• Consider seat width and height carefully—narrower and shorter suspension profiles generally fit best.
• Optional equipment like HVAC ducts or in-cab storage boxes can affect clearance and mounting options.