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Chevrolet Silverado / GMC Sierra. Manual - part 1031
OIL OUT THE VENT
Oil Out the Vent
VIBRATION IN REVERSE AND WHINING NOISE IN PARK
Vibration in Reverse and Whining Noise in Park
RATCHETING NOISE
Ratcheting Noise
TICKING NOISE IN REVERSE
Ratcheting Noise
POPPING NOISE
Checks
Causes
Input Speed Sensor
ISS loose in bore
ISS O-Ring
Damaged or missing
Oil Pump (4)
Chamber in pump body rotor pocket
Miscellaneous
Fluid level-overfilled
Checks
Causes
Oil Pump (4)
Chamber in pump body rotor pocket
Miscellaneous
Fluid level-overfilled
Checks
Causes
Parking Brake Pawl (50-81) The parking pawl return spring is weak, damaged, or
misassembled
Checks
Causes
Parking Brake Pawl (50-81) This noise may be caused by a bent parking lock actuator
assembly (85). A bent actuator may not fully move the pawl
(81) away from the internal reaction gear (684) when in
reverse allowing the pawl to lightly contact the teeth of the
internal reaction gear. The condition my not occur in forward
gears as the additional actuator travel moves the pawl further
from the gear teeth.
To correct this condition, replace the parking lock actuator
assembly (85).
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis
Silverado, Sierra & Silverado
Popping Noise
WHINE NOISE VARYING WITH RPM OR FLUID PRESSURE
Whine Noise Varying with RPM or Fluid Pressure
BUZZ NOISE OR HIGH FREQUENCY RATTLE SOUND
Buzz Noise or High Frequency Rattle Sound
NOISE IN RANDOM RANGES
Checks
Action
DEFINITION: A popping noise, similar to popcorn popping
Oil Pump System
Check fluid level.
Inspect for pump cavitation, indicated by bubbles in
fluid.
Inspect the transmission fluid filter for a leaky seam.
Inspect the transmission fluid filter seal for improper
positioning or for a cut seal.
Checks
Action
DEFINITION: In all ranges, a whine which may be sensitive to RPM load, or which ceases
when the TCC engages, or which is sensitive to the oil pressure
Torque Converter (1)
Verify that the noise is internal to the torque converter by
placing your left foot on the brake with the gear or selector in
Drive. Momentarily stall the engine. Torque Converter noise
increases under load.
Oil Pump System
Verify that the noise is internal to the oil pump during a
preliminary oil pressure check. An increase in line pressure
will vary an oil pump noise.
Checks
Action
DEFINITION: A buzz or high frequency rattle
Trace Cooler Pipes
Check for binding or
contact at the Radiator,
other than at the Cooler
Pipe connectors
Verify a pressure buzz by watching for a needle vibration of
the pressure gage. A road test may be necessary. Refer to
Road Test.
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis
Silverado, Sierra & Silverado
Noise in Random Ranges
NO DRIVE IN ALL RANGES
No Drive in All Ranges
NO DRIVE IN DRIVE RANGE
SHIFT LEVER INDICATES WRONG GEAR
Checks
Action
DEFINITION: Noise only in certain gear ranges
Refer to Range Reference . Determine the power flow and the applicable components that
may be causing this noise.
Checks
Causes
Low Transmission Fluid
Level
Transmission or cooler line leak
Oil Pump (4)
Damaged oil pump rotor (212)
Torque Converter (1)
The converter is not bolted to flex plate
Damaged pump drive
The stator roller clutch is not holding
Checks
Causes
Oil Pump (4)
Damaged vanes
Missing slide spring
Oil pump screen assembly plugged or damaged
Oil pump rotor guide omitted or misassembled
Oil pump rotor cracked or broken
Porosity in fluid pump
Oil pump surfaces not flat
Excessive oil pump rotor clearance
Forward Sprag Clutch
Assembly (642)
Damaged sprag
Worn or pitted inner race
Input (662) and Reaction
(681) Carrier
Damaged or worn gears
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis
Silverado, Sierra & Silverado
Shift Lever Indicates Wrong Gear
NO GEAR SELECTION
No Gear Selection
ENGINE STARTS IN GEAR
Engine Starts in Gear
DELAY IN DRIVE AND REVERSE
Delay in Drive and Reverse
Checks
Causes
Manual Valve (340)
Not engaged to detent lever
Detent Roller Pin (63)
Missing or damaged
Detent Roller (63)
Broken or disconnected
Detent Spring (63)
Broken or disconnected
Manual Valve Link (89)
Loose or missing
Manual Shaft (84)
Flats not parallel
Indicator Linkage
Misadjusted
Checks
Causes
Detent Lever (63)
Nut loose or missing
Manual Valve (84)
Stuck
Spacer Plate/Gaskets (47,
48, 52)
Blocked holes
Control Valve Body to Case
(60/103)
Blocked channels
Checks
Causes
Manual Valve (24)
Not engaged to detent lever
Transmission Range Switch Not working or mispositioned
Checks
Causes
Forward Clutch Piston (630) Cut or damaged piston seals
Low and Reverse Clutch
Piston (695)
Cut or damaged inner, outer or center clutch seals
Reverse Input Clutch Piston
Assembly (607)
Cut or damaged inner or outer clutch seals
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis
Silverado, Sierra & Silverado
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