1999 GMC W4500 Forward Service and Repair Manual
This factory service and repair manual for the 1999 GMC W4500 Forward has two engines to account for on one low-tilt straight truck in the W4S042 build. The gasoline unit is a 5.7L V8 of 350 cubic inches, overhead-valve and naturally aspirated; the diesel is a turbocharged 4.8L inline-four of 290 cubic inches. They demand different service intervals and different diagnostic routines, and the manual treats them separately while keeping one set of procedures, specifications, torque values and wiring diagrams for the shared chassis.
Engines covered
- 5.7L V8 (350 cu in) — OHV, naturally aspirated, gasoline
- 4.8L inline-four (290 cu in) — turbocharged, diesel
Body styles covered
- Straight truck, low tilt
Trims covered
- W4S042
Known issues on the 1999 W4500 Forward. There is no recall history on the 1999 W4500 Forward and no owner complaints at NHTSA either. That leaves the manual to cover what wears rather than what was defective: fuel injection and turbocharger service on the 4.8L diesel, fuel and ignition specifications on the 5.7L V8, cooling, lubrication and belt-drive procedures for both, cab tilt and mounting hardware, brake, steering and suspension service with their torque values, and wiring diagrams and diagnostic charts for the charging, starting and lighting circuits.
