This factory service and repair manual for the 1991 GMC W6500 Forward covers the turbocharged 5.8L inline-six of 353 cubic inches, a diesel, as the sole engine in a low tilt straight truck carrying the W6R042 trim code. There is nothing conditional about the content on that account: a specification quoted anywhere in the book is the specification for the truck being worked on, and the diagnostic procedures assume its exact hardware rather than a family of related builds.
Engines covered
- 5.8L inline-six (353 cu in) — turbocharged, diesel
Body styles covered
- Straight truck, low tilt
Trims covered
- W6R042
Known issues on the 1991 W6500 Forward. No recalls appear against the 1991 W6500 Forward federally, and NHTSA has no owner complaints on record for it. Since there is no known pattern failure to plan around, the manual works as a straightforward reference for the turbocharged 353 cubic inch diesel and the chassis around it, carrying the procedures, specifications, torque values, wiring diagrams and diagnostics for both.
