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Fluid Pressure Sensor/Switch: Customer Interest
A/T - Buzzing Noise at Idle

BULLETIN NUMBER:
93-7A-18

SECTION:
7A

NUMBER:
4

CORPORATE
REFERENCE NUMBER:
277142

DATE:
October 1992

SUBJECT:
BUZZING NOISE AT IDLE (INSTALL NEW PRESSURE REGULATOR VALVE)

MODELS:
1982-93 C/K, R/V, S/T TRUCKS AND G/M/L VANS WITH 4L60 TRANSMISSIONS

CONDITION:
Some 1982-93 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle
is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle.

CAUSE:
The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM.

CORRECTION:

Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Technical Service Bulletins > Customer Interest for Fluid Pressure Sensor/Switch: > 937A18 > Oct > 92 > A/T - Buzzing Noise at Idle

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