This factory service and repair manual for the 2007 GMC W3500 Forward covers a single-build-code truck, W3S042, available with either of two engines: the naturally aspirated 6.0L overhead-valve V8 of 364 cubic inches on gasoline, or the turbocharged 5.2L inline-four of 317 cubic inches on diesel. The engines differ; the cab, frame, brakes, steering and driveline behind them do not, and the manual reflects that, giving shared systems one treatment and reserving separate procedures, specifications, torque values, wiring diagrams and diagnostics for each engine.
Engines covered
- 6.0L V8 (364 cu in) — OHV, naturally aspirated, gasoline
- 5.2L inline-four (317 cu in) — turbocharged, diesel
Trims covered
- W3S042
Known issues on the 2007 W3500 Forward. Four recalls are on the federal record for the 2007 W3500 Forward. One covers fuel tanks that can corrode until they leak. Another concerns diesel fuel seeping from the pipe where it meets a port on the supply pump. A third traces to oil pipe bolts that were never tightened to specification, loosening in service, letting oil past the packing seals and risking a seizure that slows the truck without warning. One owner complaint is logged, and it concerns the steering. Fuel supply, engine lubrication and steering all have procedures, specifications and diagnostics in this manual.
