Chevrolet Silverado / GMC Sierra. Service manual — part 1029

NO REVERSE OR SLIPS IN REVERSE

No Reverse or Slips in Reverse

1-2 Shift valve train

3-2 Shift solenoid valve assembly

Spacer plate or gaskets incorrect, mispositioned or
damaged

2-4 Servo Assembly (13-28)

Incorrect band apply pin

Missing or damaged servo seals

Porosity in piston, cover or case

Damaged piston seal grooves

Plugged or missing orifice cup plug

Case (103)

3rd Accumulator retainer and ball assembly leaking

Porosity in 3-4 accumulator piston or bore

3-4 Accumulator piston seal or seal grooves damaged

Plugged or missing orifice cup plug

Restricted oil passage

Input Housing Assembly
(621)

Refer to No 2-3 Shift or 2-3 Shift Slips, Rough or
Hunting.

2-4 Band Assembly (602)

Worn or misassembled

Checks

Causes

Input Housing Assembly
(602)

3-4 Apply ring stuck in applied position

Forward clutch not releasing

Turbine shaft seals missing, cut or damaged

Manual Valve Link (89)

Disconnected

Valve Body Assembly (60)

2-3 Shift valve stuck

Manual linkage not adjusted

Spacer plate and gaskets incorrect, mispositioned or
damaged

Lo overrun valve stuck

Orificed cup plug restricted, missing or damaged

Reverse Input Clutch

Clutch plate worn

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

NO PART THROTTLE OR DELAYED DOWNSHIFTS

No Part Throttle or Delayed Downshifts

Assembly (605-614)

Reverse input housing and drum assembly cracked at
weld

Clutch plate retaining ring out of groove

Return spring assembly retaining ring out of groove

Seals cut or damaged

Restricted apply passage

Porosity in piston

Belleville plate installed incorrectly

Excessive clutch plate travel

Oversized housing

Lo and Reverse Clutch
(694-696)

Clutch plates worn

Porosity in piston

Seals damaged

Return spring assembly retaining ring mispositioned

Restricted apply passage

Reaction Sun Shell (670)

Broken spline on reaction sun shell/replace shell

Checks

Causes

Input Housing Assembly
(621)

3-4 Apply ring stuck in applied position

Forward clutch not releasing

Turbine shaft seals missing, cut or damaged

Manual Valve Link (89)

Disconnected

Valve Body Assembly (60)

2-3 Shift valve stuck

Manual linkage not adjusted

Spacer plate and gaskets incorrect, mispositioned or
damaged

Lo overrun valve stuck

Orificed cup plug restricted, missing or damaged

Reverse Input Clutch
Assembly (606-614)

Clutch plate worn

Reverse input housing and drum assembly cracked at

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

HARSH GARAGE SHIFT

Harsh Garage Shift

NO OVERRUN BRAKING - MANUAL 3-2-1

No Overrun Braking - Manual 3-2-1

weld

Clutch plate retaining ring out of groove

Return spring assembly retaining ring out of groove

Seals cut or damaged

Restricted apply passage

Porosity in piston

Belleville plate installed incorrectly

Excessive clutch plate travel

Oversized housing

Lo and Reverse Clutch
(694-696)

Clutch plates worn

Porosity in piston

Seals damaged

Return spring assembly retaining ring mispositioned

Restricted apply passage

Checks

Causes

Valve Body Assembly (60)

Orifice cup plug missing

Checkball missing

Checks

Causes

External Linkage

Not adjusted properly

Valve Body Assembly (60)

4-3 Sequence valve stuck

Checkball mispositioned

Spacer plate and gaskets incorrect, damaged or
mispositioned

Overrun and Forward
Clutch Assembly (644-651)

Turbine shaft oil passages plugged or not drilled

Turbine shaft seal rings damaged

Turbine shaft sealing balls loose or missing

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

NO TORQUE CONVERTER CLUTCH APPLY (300 RPM SLIP)

No Torque Converter Clutch (TCC) Apply

Porosity in forward or overrun clutch piston

Overrun piston seals cut or damaged

Overrun piston checkball not sealing

Checks

Causes

Valve Body Assembly (60)

Regulator apply valve side loading

Stuck converter clutch valve

Torque converter clutch (TCC) apply valve stuck closed
(debris in bore)

Torque converter clutch pulse width modulated (TCC
PWM) solenoid broken/cracked

Turbine shaft O-ring omitted

TCC PWM solenoid leaking

Input Housing and Turbine
Shaft Assembly (621)

Turbine shaft hole not drilled to full depth

Scratched turbine shaft journals

Turbine shaft O-ring omitted/damaged

Turbine shaft retainer and ball assembly restricted or
damaged

Electrical

12 volts not supplied to transmission

Outside electrical connector damaged

Inside electrical connector damaged

Wire harness damaged

TCC solenoid damaged

Electrical short (pinched wire)

TCC solenoid not grounded

Torque Converter Clutch (1) Internal damage (blue or distorted)
Oil Pump Assembly (4)

TCC spring cocked

Orifice cup plug restricted or damaged

Pump to case gasket mispositioned

Converter clutch valve retaining ring mispositioned

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado