Custom Cruiser RWD V8-350 5.7L (1992)
Fluid Pressure Sensor/Switch: Customer Interest
A/T - Buzzing Noise On Engine Shutdown
NUMBER: 93-T-13
CORP.REF.NO: 277141, 277142
DATE: November 1992
SECTION: 7, 4L60, 4L60-E
SUBJECT:
BUZZING NOISE ON ENGINE SHUTDOWN - INSTALL NEW PRESSURE REGULATOR VALVE
MODELS/YEARS:
1991-92 CUSTOM CRUISER AND
1991-93 BRAVADA W/4L60 OR 4L60-E TRANSMISSION
CONDITION:
Some 1991-92 Custom Cruiser, and 1991-93 Bravadas equipped with the HYDRA-MATIC 4L60 or 4L60-E transmission may exhibit a buzzing noise
coming from the transmission on engine shutdown.
CAUSE:
The buzzing noise may be a result of the pressure regulator valve oscillating due to oil pressure instability during engine shutdown.
CORRECTION:
A new pressure regulator valve has been released which will improve the oil pressure stability at lower RPM. Parts are currently available from GMSPO.
This repair can be performed on a 1993 4L60-E prior to January 1, 1993 even though the pressure regulator valve is not included in the list of service
parts available in Dealer Technical Bulletin 93-T-07.
