This factory service and repair manual for the 1988 GMC W7500 Forward covers the low tilt straight truck in the W7R042 trim, with two turbocharged diesel engines on the list: the 8.4L inline-six at 513 cubic inches and the 5.8L inline-six at 353. For a fleet that bought both, the book removes the guesswork of which figure applies where, since each engine's specifications, torque values and diagnostic procedures are stated separately and the chassis coverage runs common to both.
Engines covered
- 8.4L inline-six (513 cu in) — turbocharged, diesel
- 5.8L inline-six (353 cu in) — turbocharged, diesel
Body styles covered
- Straight truck, low tilt
Trims covered
- W7R042
Known issues on the 1988 W7500 Forward. Federally, the 1988 W7500 Forward has nothing against it, with no recalls and no owner complaints recorded by NHTSA. The manual's job is therefore the ordinary one of keeping a working truck working, with procedures and specifications for both turbocharged sixes, torque values for the assemblies they drive, and wiring diagrams complete enough to diagnose an electrical fault on a chassis that has been in service for decades.
