This factory service and repair manual for the 1999 GMC W5500 Forward is written around a four-cylinder: a 4.8L inline-four of 290 cubic inches, turbocharged and diesel-fueled, and the only engine listed for the year. The truck is the low tilt straight truck in trim code W5S042. A smaller engine does not mean a smaller job list, and the procedures, specifications, torque values, wiring diagrams and diagnostics here cover the engine and the chassis it is installed in with equal detail.
Engines covered
- 4.8L inline-four (290 cu in) — turbocharged, diesel
Body styles covered
- Straight truck, low tilt
Trims covered
- W5S042
Known issues on the 1999 W5500 Forward. There is nothing against the 1999 W5500 Forward on the federal record: no recalls, and no owner complaints logged with NHTSA. The manual's content is what matters here, and it stays on the turbocharged 4.8L inline-four and the W5S042 chassis, with diagnostics for running faults, specifications for the tolerances a repair has to hold, torque values for reassembly, and wiring diagrams for the truck's electrical circuits.
