Automatic Transmission - 4l80-e - Overhaul & Testing Chevrolet Avalanche I

APPLICATION

TRANSMISSION APPLICATION

Transmission is identified by metal identification plate attached to rear face of transmission case. (Scheme 1)

Scheme 1

GEAR RATIOS

TRANSMISSION GEAR RATIOS

DESCRIPTION & OPERATION

Hydra-Matic 4L80-E transmission is a fully automatic 4-speed unit consisting primarily of a hydraulic torque converter and torque converter clutch. Transmission uses a gear-type oil pump to supply all hydraulic pressure needed for operation. Other internal components include 5 multiple disc clutches, 2 roller clutches, a sprag clutch, 2 bands, 2 speed sensors and 3 compound planetary gear sets.

Hydra-Matic 4L80-E also uses 2 electronic shift solenoids. Shift solenoids are controlled by Powertrain Control Module (PCM), Transmission Control Module (TCM), or Vehicle Control Module (VCM), depending on vehicle model and engine application.

Note. Unless specified otherwise, references to "control module" throughout this article refer to PCM, TCM or VCM, depending on application.

LUBRICATION

Note. See appropriate SERVICING article.

TROUBLE SHOOTING

Note. Transmission malfunctions may be caused by poor engine performance, improper adjustments, fluid condition or failure of hydraulic, mechanical or electronic components. Ensure all concerns are thoroughly checked prior to transmission overhaul. See appropriate DIAGNOSIS article.

Inspection

A visual inspection of torque converter may reveal converter is Blue from overheating. If torque converter has been removed from vehicle, stator roller clutch can be checked by inserting a finger into splined inner race of roller clutch and attempting to rotate race in both directions. Inner race should rotate freely, but should not rotate or should be difficult to rotate counterclockwise.

Torque converter must be replaced for any of the following reasons

1. Damage To Pump Assembly
2. Metal Particles Present In Oil
3. Leaks In Hub Weld Area
4. Hub Scored Or Damaged
5. Stator Failure
6. Torque Converter Imbalance
7. Excessive End Play

Torque Converter End Play Check

Mount Torque Converter End Play Fixture (J-391985) and Dial Gauge (J-8001) with Magnetic Indicator Base (J-26900-13) on torque converter to check end play. Push down on fixture handle to bottom stator. Zero dial gauge. Pull up on fixture handle and check reading. End play should be 0-.015" (0-.39 mm).

CASE EXTENSION & SPEED SENSORS

Thoroughly clean transmission exterior. Drain fluid and remove torque converter. Place transmission in holding fixture. Using slide hammer, remove slip yoke seal. Remove case extension bolts, case extension and seal. Remove case extension bearing assembly (some models). Remove input speed sensor and output speed sensor (output speed sensor plug on 4WD models). (Scheme 2)

Scheme 2

LOWER TRANSMISSION ASSEMBLY

1. Remove oil pan, gasket and oil filter. Remove wiring harness. (Scheme 3)and (Scheme 69). Remove accumulator assemblies. (Scheme 4)and (Scheme 54). Remove TFP position switch (also referred to as pressure switch assembly). (Scheme 4)
2. Remove valve body bolts. Remove valve body assembly. Remove spacer plates and gasket. (Scheme 4) Remove check balls and PWM solenoid screen from case. (Scheme 5) Remove parking pawl and manual linkage. (Scheme 6)

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Low-Reverse Band Apply Pin Selection

1. Remove servo covers and assemblies. (Scheme 4), (Scheme 52) and (Scheme 53).
2. Install Band Apply Selector Pin (J-21370-10) into servo bore. (Scheme 7) Mount Band Apply Pin Selector Gauge (J-38737) and selector pin on transmission. (Scheme 8) Apply 25 ft. lbs. (34 N.m) of torque to hex nut on gauge.
3. Note which step on selector pin lines up with top edge of apply pin gauge. Use this information to determine pin length. (Scheme 7)and (Scheme 9). Record length for reassembly. Pins are available in various lengths. (Scheme 9)

Scheme 7

Scheme 8

Scheme 9

END PLAY CHECKS

1. Using dial indicator, check front and rear unit end play. (Scheme 10)and (Scheme 11). Press down on turbine shaft and then pull up on turbine shaft to eliminate any clearance between overdrive carrier and snap ring. Pull up on turbine shaft while holding output carrier upward with screwdriver to measure front unit end play. Front unit end play should be.004-.022" (.10-.56 mm).
2. Push in on output shaft to take up any slack. Move output shaft inward and outward to measure rear unit end play. Rear unit end play should be.005-.025" (.13-.64 mm). Record measurements for reassembly reference.

Scheme 10

Scheme 11

OIL PUMP ASSEMBLY

Using puller, remove torque converter oil seal. (Scheme 12) Remove oil pump assembly-to-transmission case bolts. Using Removal Tool (J-37789-A), remove oil pump assembly. Remove gasket and thrust washer. (Scheme 67)

Scheme 12

OVERDRIVE ASSEMBLY & 4TH CLUTCH

Remove turbine shaft and overdrive carrier assembly. (Scheme 38) Using appropriate Torx wrench, remove 4th clutch housing bolt and discard. (Scheme 13) Remove 4th clutch assembly.

Scheme 13

FORWARD & DIRECT CLUTCH

Using Clutch Remover/Installer (J-38358-A), remove forward clutch assembly. (Scheme 62) Using Clutch Remover/Installer (J-38733), remove direct clutch assembly. (Scheme 61)

MANUAL 2-1 BAND & INTERMEDIATE CLUTCH

Note. Manual 2-1 band may also be referred to as front band.

Remove manual 2-1 band. Remove snap ring, backing plate and intermediate clutch plates. Remove intermediate clutch wave plate. (Scheme 60)

CENTER SUPPORT, REAR GEAR UNIT & LOW-REVERSE BAND

Note. low-reverse band may also be referred to as rear band.

1. Remove center support bolt and discard. (Scheme 59) Remove snap ring. Using Gear Assembly Remover/Installer (J-38868), Adapter (J-21364-A) and slide hammer handle, remove gear assembly. (Scheme 58)
2. Remove low-reverse band and thrust washer. (Scheme 56) If necessary, select proper selective thrust washer based on end play measurements. See «END PLAY CHECKS»(/chevrolet/avalanche/i-2001-2006/remont/automatic-trans/#automatic-transmission-4l80-e-overhaul-testing__end-play-checks). Set thrust washer aside for reassembly.
3. Remove output shaft seal snap ring. Using slide hammer, remove output shaft seal.

TRANSMISSION CASE

Note. Always use manufacturer-recommended transmission fluid during cleaning or reassembly of transmission components. See LUBRICATION in appropriate SERVICING article. Use petroleum jelly to hold bearings and spacers in position.

Cleaning & Inspection

Thoroughly clean transmission case with solvent and dry using compressed air. Inspect transmission case for damage to band lugs, snap ring grooves, drive sprocket bearings, interconnected or damaged oil passages and servo bores. Inspect case for stripped threads in bolt holes or casting porosity. Check transmission case oil passages for restrictions or blockage. Blow compressed air through all transmission case oil passages. (Scheme 14) Repair or replace transmission case if necessary.

Scheme 14

DO NOT wash bands in solvent. Inspect each band assembly for wear, pitting, flaking and cracks. Check band stop for damage and replace if necessary. If low-reverse band is replaced, recheck apply pin. See SERVO ASSEMBLIES under TRANSMISSION DISASSEMBLY.

Disassembly

Remove snap rings. Separate center support, output carrier, reaction carrier and parts of rear gear unit. (Scheme 15)

Using clutch spring compressor and adapter, compress intermediate clutch springs and remove snap ring. Separate center support from intermediate clutch assembly. (Scheme 16)

1. Inspect output carrier, reaction carrier and reaction drum for damaged teeth, scoring or warpage. Check thrust bearing for damage. Using feeler gauge, check output carrier and reaction carrier pinion gear end play. (Scheme 17)and (Scheme 18).
2. End play should be.009-.024" (.23-.61 mm). Check for damage to reaction carrier internal gear. Ensure center support cup plug bleed hole opening is about.020" (.51 mm). (Scheme 19)

Center Support Recondition Procedure

If Bore Gauge (J-39919-2) fits into center support bolt hole, replace center support and bolt in order to avoid component damage. To determine if center support has not been previously reconditioned, insert bore gauge into center support bolt hole. If gauge does not fit, using Thread Reamer (J-39919-1), ream center support bolt hole to fit NEW service bolt. (Scheme 30)

Reassembly

Using Piston Installer (J-21363), install intermediate piston to center support. (Scheme 20) Reassemble center support and rear gear unit. (Scheme 21)- (Scheme 24). Install NEW oil seal rings to center support. Soak in manufacturer-recommended transmission fluid prior to installation. See LUBRICATION in appropriate SERVICING article.

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

1. Remove intermediate clutch roller snap ring. Remove intermediate clutch sprag assembly and race, as an assembly. Remove intermediate clutch roller outer race. Inspect intermediate clutch sprag assembly for damaged rollers, damaged cage or distorted springs.
2. Remove direct clutch backing plate snap ring and backing plate. Remove direct clutch plates. Remove direct clutch (waved) plate. Inspect direct clutch backing plate and direct clutch plates for cracks, wear, burned, flaking, scoring and pitting. Install (J-23327 and J-25018-A) spring compressor and adapter, onto direct clutch housing assembly. (Scheme 25) Compress direct clutch spring assembly.
3. Remove direct clutch spring snap ring, and remove spring assembly. Inspect direct clutch spring assembly for collapsed coils and distortion. Remove direct clutch piston assembly. Direct clutch piston assembly is reusable unless it is damaged. Inspect direct clutch piston assembly for damage and cracks. (Scheme 26) Remove direct clutch piston intermediate seal from direct clutch housing assembly.

Scheme 26

Inspect all parts for wear, cracks, burned plates and scoring; replace if necessary.

Scheme 27

1. Install direct clutch piston intermediate seal onto direct clutch housing assembly with seal lip facing upward. Lubricate direct clutch piston assembly with manufacturer-recommended transmission fluid. See LUBRICATION in appropriate SERVICING article. Install (J-21362-1 and J-38732-1) onto direct clutch housing assembly. (Scheme 27) Lubricate tools with manufacturer-recommended transmission fluid. See LUBRICATION in appropriate SERVICING article. Install direct clutch piston assembly into direct clutch housing assembly using rotating motion until direct clutch piston assembly is seated.
2. Install direct clutch spring assembly. Install Spring Compressor and Adapter (J-23327 and J-25018-A) onto direct clutch housing assembly. Compress direct clutch spring assembly, and install direct clutch spring snap ring. Dip all of direct clutch plates in manufacturer-recommended transmission fluid. See LUBRICATION in appropriate SERVICING article. Install direct clutch (waved) plate. Alternate clutch plates, starting with steel clutch plate (5 steel, 5 composite). Install direct clutch plates. Install direct clutch backing plate. Install direct clutch backing plate snap ring.
3. Turn direct clutch housing assembly over. Assemble intermediate clutch sprag assembly into intermediate clutch roller outer race. Install intermediate clutch roller outer race (with grooved side facing up), using a clockwise rotating motion to ease assembly. Clutch roller outer race should not rotate counterclockwise. Install intermediate clutch roller retainer. If intermediate sprag clutch retainer snap ring has been removed, you must use a NEW ring. Install intermediate clutch roller retainer snap ring onto hub of direct clutch housing assembly. Use Snap Ring Installer (J-38695) in order to complete the installation of intermediate clutch roller retainer snap ring. (Scheme 28) Rotate installer counterclockwise while pressing down.
4. To check piston travel, attach (J-7057) extension, (not visible in illustration) to (J-8001-3) dial indicator set. (Scheme 29) Using indicator, mount it to transmission case through opening in case barrel. Place extension onto direct clutch piston assembly. Index dial indicator to Zero. Apply 80 psi of air pressure to direct clutch fluid passage (3rd-Reverse), in case bottom, in order to actuate direct clutch piston. Measure direct clutch piston travel. Piston travel should be.050-.172" (1.3-4.4 mm).

Scheme 28

Scheme 29

Scheme 30

1. Remove direct clutch hub snap ring. (Scheme 31) Remove direct clutch hub. Remove direct clutch housing thrust washer (plastic). Remove forward clutch hub and thrust washer (bronze). Washer may stick to forward clutch housing assembly. Inspect direct clutch hub for spline wear, open lubrication holes or damaged clutch surface.
2. Remove forward clutch snap ring. Remove forward clutch spring assembly. Inspect forward clutch spring assembly for collapsed spring coils and distortion. Remove forward clutch piston assembly (forward clutch piston assembly is reusable if it is not damaged). Inspect forward clutch piston assembly for cracks. Inspect seal on forward clutch piston assembly for cuts, tears and nicks.
3. Remove forward clutch steel and composite plates. Remove forward clutch (waved) plate. Inspect forward clutch plates for burning, scoring, flaking, pitting or wear. Using Spring Compressor and Adapter (J-23327 and J-25018-A), compress forward clutch spring assembly. (Scheme 33) Forward clutch piston intermediate seal assembly is reusable. Replace forward clutch housing assembly if seal is worn or damaged. Inspect forward clutch piston intermediate seal assembly for cuts, tears and nicks. Inspect forward clutch housing assembly for wear, restricted or clogged oil passages, damaged thrust faces and free movement of checkball.

Inspect all clutch plates for cracks, wear, lining separation, pits or other signs of damage. Ensure forward clutch housing check ball is working. Inspect thrust washer for damage. Inspect clutch housing for damaged clutch hub, worn bushings or damaged oil seal rings.

1. Install direct clutch piston intermediate seal onto direct clutch housing assembly with seal lip facing upward. Lubricate direct clutch piston assembly with manufacturer-recommended transmission fluid. See LUBRICATION in appropriate SERVICING article. Install Seal Installers (J-21362-1 and J-38732-1) onto direct clutch housing assembly. (Scheme 27) Lubricate tools with manufacturer-recommended transmission fluid. Install direct clutch piston assembly into direct clutch housing assembly using a rotating motion until direct clutch piston assembly is seated. Install direct clutch spring assembly. Install Spring Compressor and Adapter (J-23327 and J-25018-A) onto direct clutch housing assembly. Compress direct clutch spring assembly. Install direct clutch spring snap ring.
2. Dip all direct clutch plates in manufacturer-recommended transmission fluid. Install direct clutch (waved) plate. Alternate clutch plates, starting with steel clutch plate (5 steel, 5 composite). (Scheme 31) Install direct clutch plates. Install direct clutch backing plate. Install direct clutch backing plate snap ring. Turn direct clutch housing assembly over. When installing intermediate clutch sprag assembly, lip of cage must face direct clutch housing assembly. Assemble intermediate clutch sprag assembly into intermediate clutch roller outer race. Install intermediate clutch roller outer race with grooved side facing up. Use a clockwise rotating motion to ease assembly.
3. Clutch roller outer race should not rotate counterclockwise. Install intermediate clutch roller retainer. If intermediate sprag clutch retainer ring has been removed, a NEW ring must be used. Install intermediate clutch roller retainer snap ring onto hub of direct clutch housing assembly. Use Snap Ring Installer (J-38695) in order to complete installation of intermediate clutch roller retainer retaining ring. (Scheme 28) Rotate installer counterclockwise while pressing down.
4. To check forward clutch piston travel, place turbine shaft in a soft-jawed vice. Install forward clutch housing assembly onto turbine shaft. Install dial indicator. (Scheme 32) With index finger, close one side of fluid passage. Apply compressed air to other side, piston should travel.050-.172" (1.3-4.4 mm).

Scheme 31

Scheme 32

Scheme 33

1. Remove 4th clutch backing plate snap ring. Remove 4th clutch backing plate. Remove clutch plates. Install clutch housing onto Spring Compressor Adapter (J-38731-3). (Scheme 34) Using Spring Compressor (J-38882) and Adapter (J-23327), compress 4th clutch spring assembly. Remove 4th clutch spring snap ring.
2. Remove Spring compressor and adapter. Remove 4th clutch spring assembly. Remove 4th clutch piston. Remove 4th clutch piston inner seal. Remove 4th clutch piston outer seal from 4th clutch housing. Inspect 4th clutch orifice.

Scheme 34

Inspect housing and clutch plates for damaged teeth, scoring or warpage. Ensure 4th clutch housing cup plug bleed hole opening is about .020" (.51 mm).

1. Install 4th clutch piston inner seal onto 4th clutch piston. Install 4th clutch piston outer seal into 4th clutch housing. Seal lip should face bottom of piston when piston is installed. (Scheme 35) Place Seal Installer (J-38731-1) into 4th clutch housing through smaller opening. Place Seal Installer (J-38731-2) onto larger opening of 4th clutch piston. Place Seal Installer (J-38731-2) and 4th clutch piston onto Seal Installer (J-38731-3). (Scheme 35) Install 4th clutch piston into 4th clutch housing by gently pushing down on 4th clutch housing, until 4th clutch piston is through 4th clutch housing, exposing retainer ring groove.
2. Place 4th clutch spring assembly and 4th clutch spring retainer ring onto 4th clutch piston. Using Spring Compressor and Adapters (J-38882), (J-23327) and (J-38731-3), compress 4th clutch spring. (Scheme 34) Install 4th clutch spring retainer ring. Alternate clutch plates, starting with steel clutch plate (4 steel and 4 composite). (Scheme 36) Locate steel plate index notch opposite 4th clutch bolt hole. Install 4th clutch plates into 4th clutch housing. Install 4th clutch backing plate. Align notched tab in same direction as steel plate index notches. Install 4th clutch backing plate retainer ring.
3. Using a feeler gage, measure piston travel between 4th clutch backing plate and 4th clutch backing plate retainer ring. Piston travel should be.040-.100" (1.02-2.54 mm). (Scheme 37)

Scheme 35

Scheme 36

Scheme 37

Remove overrun clutch housing from overdrive carrier assembly. (Scheme 38) Disassemble overrun clutch. (Scheme 39)and (Scheme 47). Using clutch spring compressor and adapter, compress spring retainer and remove clutch piston. (Scheme 40) Disassemble overdrive assembly. (Scheme 47) If necessary, disassemble overdrive carrier assembly. (Scheme 46)

Scheme 38

Scheme 39

Scheme 40

Inspect housing and clutch plates for damaged teeth, scoring or warpage. Inspect spring and spring retainer for damage. Inspect overdrive carrier assembly and turbine shaft for wear or damage. Replace if necessary. Using feeler gauge, ensure overdrive carrier pinion end play is.008-.025" (.20-.64 mm). (Scheme 43)

Scheme 41

1. Remove oil seal rings from turbine shaft. Inspect seal ring grooves for nicks or burrs. Lubricate each oil seal ring. Place Seal Protector/Installer Kit (J-38736) on turbine shaft. (Scheme 41)
2. Quickly slide each seal into ring groove when protector is in position. Use seal driver from Kit (J-38736) to push ring over seal protector. Size seal with seal sizer from Kit (J-38736); gently twist seal sizer over each seal. Leave sizer in place.

1. Using Piston Seal Protector/Installer (J-38729), install piston into overrun clutch housing. (Scheme 42) Lubricate seal with manufacturer-recommended transmission fluid. See LUBRICATION in appropriate SERVICING article. Rotate overrun clutch to aid in assembly. (Scheme 39)
2. Install spring and compress, using compressor. (Scheme 40) Install snap ring. Install steel plate, and then alternate between composition plate and steel plate. Overrun clutch uses 3 steel and 3 composition plates. Install backing plate and snap ring. Using feeler gauge, ensure clearance between backing plate and snap ring is.033-.094" (.84-2.38 mm). (Scheme 44)
3. If necessary, reassemble overdrive carrier. (Scheme 45)- (Scheme 47). Install thrust washer into overdrive carrier. (Scheme 46) To complete reassembly, install turbine shaft and overdrive carrier to overrun clutch. (Scheme 38)and (Scheme 47). When turbine shaft and overdrive carrier are installed into transmission case, install thrust washer onto overrun clutch housing. Place a straightedge from oil pump mating surface to overrun clutch housing thrust washer. (Scheme 48) Both surfaces should be flush.

Scheme 42

Scheme 43

Scheme 44

Scheme 45

Scheme 46

Scheme 47

Scheme 48

Clean and air dry oil pump. Disassemble oil pump. (Scheme 49) Note location and direction of all components.

Inspect pump body for porosity, interconnected oil passages, damaged inner pump area surface or damaged machine facing. Check gears and bushings for damage.

1. Reassemble oil pump. Prior to assembly, lubricate all gears with manufacturer-recommended transmission fluid. See LUBRICATION in appropriate SERVICING article. (Scheme 49) Install oil pump gears into pump body with identification dots facing upward. Using straightedge, measure gear clearance between oil pump gears and pump body. Clearance should be.0008-.0028" (.020-.071 mm).
2. Ensure pump body mating surface is flat. Install pump cover onto body. Install cover bolts and hand tighten bolts. Install Alignment Pin (J-25025-1) or pump bolt into pump. Install and tighten oil pump Alignment Band (J-21368). (Scheme 51) Tighten oil pump attaching bolts.
3. To install TCC enable valve, compress spring into oil pump body and insert a small rod into hole "A". (Scheme 50) Install spring retainer and then remove small rod.

Scheme 49

Scheme 50

Scheme 51

MANUAL 2-1 & LOW-REVERSE SERVOS

Note. Manual 2-1 and low-reverse servos may also be referred to as front and rear servos.

Inspection & Reassembly

Inspect servo pistons for damage or cracks. Install NEW seals on servo pistons, if removed. Inspect springs for damaged coils. Replace all damaged parts and reassemble servos. (Scheme 52)and (Scheme 53).

Scheme 52

Scheme 53

Inspect accumulator pistons and seals for damage or cracks. DO NOT remove seals unless replacement is required. Inspect springs for damaged coils. Replace all damaged parts and reassemble accumulators. (Scheme 54)

Scheme 54

Thoroughly clean valve body and dry with compressed air. Cover bores when removing roll pins, as some valves are under pressure. Remove valves, springs and bushings and place them on a clean surface in order removed. (Scheme 55) Note location and direction of all components. Remove solenoids. Remove blind hole roll pins with drill bit. Remove servo pipe lip seals.

Clean valves, springs and bushings in clean solvent. Never use shop rags to clean valve body components. Inspect valves and bushings for scoring, nicks and scratches. Inspect springs for damaged or distorted coils. Inspect valve body casting for porosity, interconnected oil passages and damaged machined surfaces.

To reassemble valve body assembly, reverse disassembly procedure. (Scheme 55)

Scheme 55

TRANSMISSION REASSEMBLY

Note. All selective thrust washer measurements taken during disassembly must be rechecked at appropriate reassembly stage. To aid in transmission reassembly, refer to appropriate illustrations. (Scheme 71)- (Scheme 73).

CENTER SUPPORT & REAR GEAR UNIT

Note. Low-reverse band may also be referred to as rear band.

1. Install low-reverse band and thrust washer. Ensure band anchor pins engage band, and band assembly stop is in place. Install appropriate selective thrust washer. (Scheme 56)
2. Install center support spacer into groove above low-reverse band. Ensure spacer opening is place at the 9 o'clock position. (Scheme 57) Using Gear Assembly Remover/Installer (J-38868), Adapter (J-21364-A) and slide hammer handle, install gear assembly. (Scheme 58)
3. Install upper center support snap ring with beveled edge side up and opening at the 9 o'clock position. Using dial indicator, check rear unit end play. (Scheme 11) Rear unit end play should be.005-.025" (.13-.64 mm).
4. If rear unit end play is not correct, select proper size thrust washer. See «REAR END PLAY THRUST WASHER IDENTIFICATION»(/chevrolet/avalanche/i-2001-2006/remont/automatic-trans/#automatic-transmission-4l80-e-overhaul-testing) table. If necessary, remove center support and rear unit to change selective thrust washer.
5. Using Center Support Aligner (J-23093), push center support splines counterclockwise against case splines (away from rear servo). Align center support with bolt hole. Using NEW bolt, install center support bolt. (Scheme 59) Tighten bolt to 32 ft. lbs. (43 N.m). Install rear oil cooler pipe fitting with NEW seal and tighten to 26 ft. lbs. (35 N.m).

REAR END PLAY THRUST WASHER IDENTIFICATION

Scheme 56

Scheme 57

Scheme 58

Scheme 59

INTERMEDIATE CLUTCH

1. Install intermediate wave plate with tangs facing downward. Install intermediate clutch plates, starting with steel plate, and then alternating with composition plate (4 steel and 4 composition). (Scheme 60) Install backing plate with flat side down. Install snap ring at the 9 o'clock position.
2. Using feeler gauge, ensure clearance between clutch plates and backing plate is.040-.107" (1.02-2.72 mm). Install manual 2-1 band into case and ensure proper alignment with anchor pin. Using Clutch Plate Aligner (J-24396), align intermediate clutch assembly.

Scheme 60

Apply air pressure into center support hole to hold intermediate clutch plates in place. Using Clutch Installer (J-38733), install direct clutch assembly. (Scheme 61) Using Clutch Installer (J-38358-A), install forward clutch assembly and thrust bearing. (Scheme 62)and (Scheme 71).

Note. Check installed height of speed sensor ring (on forward clutch housing). Top of speed sensor ring to oil pump gasket surface height should be 3.85-3.89" (98.0-99.0 mm).

Scheme 61

Scheme 62

1. Install 4th clutch support (without clutch plates) into transmission case. Using No. 40 Torx wrench, install NEW 4th clutch support bolt. (Scheme 63) Tighten bolt to 17-19 ft. lbs. (23-26 N.m).
2. Remove turbine seal sizer from turbine shaft. Install turbine shaft and overdrive assembly. (Scheme 38) Ensure assembly is fully seated. Place a straight edge from oil pump mating surface to overrun clutch housing thrust washer. (Scheme 48) Both surfaces should be flush. Install 4th clutch plates, starting with steel plate, and then alternating with composition plate (4 steel and 4 composition). Install steel plates with narrow tang "V" notch at 1 o'clock position in housing. (Scheme 64) Install backing plate with flat side down. Install snap ring. (Scheme 65)

Scheme 63

Scheme 64

Scheme 65

1. Install Locating Pins (J-25025-1) at 12 o'clock and 5 o'clock positions. Install oil pump cover gasket. (Scheme 66) Install selective thrust washer. Using Handle (J-37789), install oil pump assembly. (Scheme 67) Ensure turbine shaft spins freely. Tighten oil pump bolts to 18 ft. lbs. (24 N.m).
2. Using dial indicator, check front unit end play. (Scheme 10) Front unit end play should be.004-.022" (.10-.56 mm). If front unit end play is not correct, select proper size thrust washer. See «OVERRUN CLUTCH HOUSING THRUST WASHER IDENTIFICATION»(/chevrolet/avalanche/i-2001-2006/remont/automatic-trans/#automatic-transmission-4l80-e-overhaul-testing) table. If necessary, remove oil pump assembly to change selective thrust washer.

OVERRUN CLUTCH HOUSING THRUST WASHER IDENTIFICATION

Scheme 66

Scheme 67

SERVO ASSEMBLIES

Note. Low-reverse and manual 2-1 bands and servos may be referred to as front and rear bands and servos.

Install selected low-reverse band apply pin. If necessary, check low-reverse band apply pin using Band Apply Selector Pin (J-21370-10) and Band Apply Pin Gauge (J-38737). See SERVO ASSEMBLIES under TRANSMISSION DISASSEMBLY. Install manual 2-1 and low-reverse servo assemblies. (Scheme 52)and (Scheme 53).

1. Install parking pawl and manual linkage. (Scheme 6) Install check balls in case. Check ball No. 2 is only used on some models. (Scheme 5) Assemble and install accumulator assembly. (Scheme 54) Tighten accumulator assembly bolts in sequence. (Scheme 68)
2. Install valve body assembly and TFP position switch. Tighten TFP position switch bolts to 97 INCH lbs. (11 N.m) in alphabetical sequence. (Scheme 69) Tighten valve body bolts in a spiral pattern in numerical order. (Scheme 70) Install lube pipe and wiring harness. (Scheme 69) Install oil pan and oil filter. (Scheme 3)

SPEED SENSORS & CASE EXTENSION

Install and secure torque converter. Install case extension. Install speed sensors. (Scheme 2)

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

TRANSMISSION SPECIFICATIONS

TRANSMISSION SPECIFICATIONS

See also:
• END PLAY CHECKS
• SERVO ASSEMBLIES
• REAR END PLAY THRUST WASHER IDENTIFICATION