SERVICE MANUAL UPDATE -SEC 6A3 FASTENER TIGHTENING SPEC.

SUBJECT: FASTENER TIGHTENING SPECIFICATIONS/TORQUE ANGLE METER

MODELS: ALL LIGHT DUTY TRUCKS WITH A 4.3L ENGINE (VIN W AND VIN Z)

The following represents new information for Section 6A3 in all 1992 Light Duty Truck Service Manuals and Section 6A4 in the 1992 Light Duty Truck Unit Repair Manual.

This information supplements information found under "Fastener Tightening Specifications."

TORQUE ANGLE METER

Torque angle meter J 36660 (figure 1) has been made an essential tool for all GM Divisions. The 4.3L engines (RPOs L35 and LB4) require the use of a torque angle meter for proper torque of two critical fasteners.

The connecting rod bolt nuts on all 4.3L engines (VIN Z and VIN W) require a torque of 27 N-m (20 lbs. ft.) plus an additional 70 degrees using J 36660.

The balance shaft driven gear bolt on the 4.3L HP engine (VIN W) requires a torque of 20 N-m (15 lbs. ft.) plus an additional 35 degrees using J 36660.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.