2025 GMC Sierra 5500HD: A Serious Platform for Heavy Truck Body Upfits
The 2025 GMC Sierra 5500HD is GM’s medium-duty Class 5 chassis cab, sitting above the popular Sierra 3500HD in GVWR and payload capacity. For contractors, utility operators, and oilfield service companies who’ve outgrown the 1-ton platform but don’t need a full Class 6 or 7 truck, the Sierra 5500HD occupies an attractive middle ground.
At Star Truck Equipment in Wharton, TX, we upfit Sierra 5500HD trucks for customers across Texas and Louisiana.
2025 GMC Sierra 5500HD Key Specifications
| Spec | 2025 GMC Sierra 5500HD |
|---|---|
| GVWR | Up to 19,500 lbs |
| Max Payload | ~12,200 lbs (with proper configuration) |
| Engine | 6.6L Duramax diesel (350 hp / 700 lb-ft torque) |
| Transmission | Allison 2500 6-speed automatic |
| Rear Axle | Dana S110 |
| Frame | Fully boxed high-strength steel |
| DRW | Yes (all 5500HD) |
| Cab Styles | Regular Cab, Crew Cab |
The Allison 2500 transmission is a major asset — Allison automatics are the gold standard in vocational trucks, known for durability under heavy PTO and repetitive load cycles that service and crane body work demands.
Cab-to-Axle (CA) Lengths
| Cab Configuration | CA Length | Recommended Body Length |
|---|---|---|
| Regular Cab, Standard CA | 84″ | 9 ft |
| Regular Cab, Extended CA | 108″ / 120″ | 11–12 ft |
| Crew Cab, Standard CA | 60″ / 84″ | 8–9 ft |
| Crew Cab, Extended CA | 108″ | 10–11 ft |
The Sierra 5500HD’s longer CA options — particularly the 108″ and 120″ configurations — make it an excellent platform for lube trucks, extended crane bodies, and large mechanics trucks that need additional body length for fluid storage and equipment.
Service Body Options
The Sierra 5500HD is one of the most capable service body platforms in the Class 5 segment. With 19,500 lb GVWR and the Allison transmission, it handles full-size 9-foot and 10-foot service bodies with ease. Popular fits from our lineup:
- CM Service Bodies — 9-ft and 11-ft configurations, excellent compartment layout for trade and contractor work
- RKI Service Bodies — Houston-made, 9-ft standard fits the 84″ CA perfectly; popular with Texas utility fleets
- STI Service Bodies — Heavy-duty build quality, ideal for demanding oilfield and pipeline environments
Crane Body Options
For crane body applications, the Sierra 5500HD is a strong choice. The Duramax diesel’s 700 lb-ft of torque provides reliable power for hydraulic PTO systems, and the Allison 2500 handles the cycling loads of crane operation without wear concerns. Crane options that pair well:
- Tiger Cranes — 3-ton to 8-ton truck-mounted cranes; the 5500HD’s payload headroom accommodates mid-size cranes without overloading
- STI Crane Bodies — Built for heavy utility and oilfield demands, ideal on the 108″ CA configuration
- RKI Crane Bodies — Solid Texas-made option for contractors and utilities
Flatbed Options
A 11-foot or 12-foot flatbed on a Sierra 5500HD with 108″ CA is a formidable hauling setup. The payload capacity means you won’t be second-guessing your load on a concrete block or equipment delivery. Best fits:
- Bedrock Granite/Diamond Flatbeds — Heavy-duty steel construction for oilfield and construction
- CM ER/TM Flatbeds — Versatile with toolbox options, works well at 11-ft on 5500HD
- Norstar AM Series — Good value, solid build for ranch and contractor applications
Mechanics Trucks and Lube Bodies
For mechanics trucks and lube/fuel service applications, the Sierra 5500HD with a 120″ CA is one of our most recommended configurations. The longer body accommodates air compressors, fluid tanks, reel systems, and generator mounts while the Allison transmission handles the constant start/stop of field service work efficiently. We recommend STI mechanics truck bodies and lube service configurations for these setups.
Sierra 5500HD vs Ram 5500 vs Ford F-550
All three Class 5 platforms are capable and well-supported in Texas. The GMC Sierra 5500HD wins on transmission (Allison standard vs. available on competitors), the Duramax’s proven longevity, and GM’s extensive Texas dealer network. If your fleet already runs GM trucks, standardizing on the 5500HD makes parts and service simpler.
Get Your Sierra 5500HD Upfitted in Wharton, TX
Star Truck Equipment supplies and installs service bodies, crane bodies, flatbeds, and mechanics trucks on the 2025 GMC Sierra 5500HD. We’ll help you select the right body for your CA length and payload requirements before you commit.
Call (979) 532-1486 or visit 2507 County Rd 231, Wharton, TX 77488. Browse options: Service Bodies | Crane Bodies | Flatbeds | Mechanics Trucks