A/C - Noise/Vibration When Compressor Engaged

87chevy29
GMC NUMBER: 88-T-56

GROUP: 1B - Air Conditioning

DATE: November, 1987

CORPORATE
NUMBER: 831203
SUBJECT: AIR CONDITIONING NOISE/VIBRATION

MODELS: 1988 C/K TRUCKS WITH AIR CONDITIONING AND 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H, AND K)
Some 1988 C/K trucks with 4.3L, 5.0L and 5.7L engines may exhibit a noise/vibration when the air conditioning is engaged. This noise/vibration is the result of a resonance set up in the serpentine accessory drive system with air conditioning on. If this condition is experienced on 1988 C/K trucks built before the VIN breakpoints listed below, install the following kits. Installation instructions are included with the kits.

Part Number Engine

10085731 4.3L V-6 With A/C

10085730 5.0L/5.7L V-8 With A/C

All 1988 C/K trucks built after the following VIN breakpoints (Last 7 digits) have had the above kits installed at the assembly plants.
Oshawa #2 Chevrolet 1178198
GMC 1528693

Fort Wayne Chevrolet Z158598
GMC Z517538

Pontiac East Chevrolet E142329
GMC E514147

V-8 Labor Operation Number: T7415 V-6 Labor Operation Number: T7420

V-8 Labor Time: .7 Hr. (+ .2 Hr. w/AIR Pump) V-6 Labor Time: .8 Hr. (+ .2 Hr. w/AIR Pump)