Transmission Rebuild - Automatic

Complete removal, disassembly, rebuild, and reinstallation of the 6R80 automatic transmission including torque converter replacement, internal component inspection and replacement, and valve body service.

Warnings

Tools required

Parts

• 6R80 transmission rebuild kit (includes clutches, steels, seals, gaskets) × 1 — Use OEM or quality aftermarket kit
• Torque converter (if worn or contaminated) × 1 — Use OEM specification
• Transmission filter × 1 — Use OEM specification
• Transmission pan gasket or RTV silicone × 1 — Check rebuild kit contents
• Transmission mount (if worn) × 1 — Use OEM specification
• Driveshaft bolts/nuts (replace if worn) × 4 — Use OEM specification
• Transmission cooler line O-rings × 4 — Included in rebuild kit
• Drain plug crush washer × 1 — Use OEM specification
• Valve body separator plate and gaskets × 1 — Included in rebuild kit
• Solenoid pack (if testing reveals failure) × 1 — Use OEM specification

Fluids

• Motorcraft MERCON LV ATF — 11 qt

Preparation

1. Ensure vehicle is on level ground with parking brake applied
2. Disconnect negative battery cable to prevent electrical issues during removal
3. Raise vehicle on lift or support securely on jack stands at appropriate lift points
4. Remove engine splash shields and transmission underbody covers
5. Drain transmission fluid from pan and torque converter (if equipped with drain plug) into appropriate container
6. Mark driveshaft-to-pinion flange orientation for reinstallation alignment
7. Take photos of electrical connections, linkage positions, and cooler line routing before disassembly
8. Clean exterior of transmission thoroughly before removal to prevent contamination during rebuild
9. Prepare clean workbench area with transmission holding fixture for rebuild process

Procedure

1. 1

   Remove transmission from vehicle
   Disconnect transmission cooler lines at transmission (use flare nut wrench to prevent damage). Disconnect electrical connectors from transmission including range sensor, solenoid pack, speed sensors, and TFT sensor. Remove starter motor. Disconnect shift linkage at transmission lever. Support engine with support bar or hoist. Remove transmission crossmember mounting bolts and crossmember. Position transmission jack under transmission pan with securing chains. Remove bellhousing-to-engine mounting bolts. Mark torque converter-to-flexplate relationship, then remove flexplate bolts through starter opening while rotating engine. Carefully separate transmission from engine, ensuring torque converter stays with transmission. Lower transmission onto transmission jack and remove from vehicle.
   Torque spec

   Mounting Bolts76 Nm (56 lb-ft)

   Flywheel Bolts95 Nm (70 lb-ft)
2. 2

   Initial transmission disassembly and inspection
   Mount transmission securely on holding fixture with bellhousing facing up. Remove torque converter and inspect for metal contamination, bearing damage, or hub wear. Remove transmission pan bolts in criss-cross pattern and remove pan. Inspect pan for metal debris or clutch material. Remove transmission filter. Remove valve body bolts (note different lengths and positions) and carefully remove valve body assembly with separator plate. Inspect separator plate for damage and verify check balls are present in correct locations (reference service manual diagram). Remove solenoid pack and inspect connectors.
   Torque spec

   Pan Bolts20 Nm (15 lb-ft)
3. 3

   Remove extension housing and output components
   Remove extension housing bolts and carefully pull housing off output shaft. Remove output shaft speed sensor. Remove output shaft snap ring and withdraw output shaft assembly. Inspect output shaft bearing and bushing for wear. Remove parking pawl assembly components including spring and actuating rod. Inspect pawl teeth for wear or damage.
4. 4

   Disassemble clutch packs and planetary assemblies
   Remove pump bolts and carefully extract pump assembly using slide hammers or appropriate puller if necessary. Remove thrust washers and bearings (keep in order). Remove forward clutch drum assembly and inspect drum for scoring. Remove direct clutch assembly. Remove intermediate clutch assembly. Use dial indicator to check end play of each component before disassembly and record measurements. Disassemble each clutch pack using spring compressor to remove snap rings. Remove clutch plates, steels, pressure plates, and springs in order. Measure clutch pack clearances and steel/friction plate thickness. Inspect drums for cracks, scoring, or heat discoloration.
5. 5

   Remove and inspect planetary gear sets and internal components
   Remove planetary gear assemblies (front and rear). Inspect planet carrier for cracks or damaged pinion pins. Check pinion gear end play with feeler gauge. Remove sun gear and reaction shaft. Inspect sun gear for worn teeth or splines. Remove reverse clutch assembly and low/reverse clutch assembly. Disassemble using spring compressor and inspect for wear. Remove one-way clutches and inspect for proper operation (should lock one direction, free-wheel other direction). Inspect case for cracks, stripped threads, or damaged bearing bores.
6. 6

   Clean and inspect all components
   Thoroughly clean all metal components in solvent or parts washer. Blow dry with compressed air, ensuring all passages are clear. Inspect all clutch drums for scoring, heat damage, or cracks. Check all snap ring grooves for damage. Inspect all bushings for wear or damage. Measure all thrust washer thickness and replace if below specification. Inspect case bearing bores for scoring. Check all sprags and one-way clutches for wear or improper operation. Inspect pump gears for wear and check pump body for scoring. Air check all apply pistons for seal integrity once cleaned.
7. 7

   Rebuild valve body and solenoid pack
   Disassemble valve body on clean workbench. Remove separator plate and note check ball positions (take photo for reference). Remove all valves, springs, and components, keeping organized by bore. Inspect all valves for scoring or wear. Inspect all bores for scoring. Replace all springs per rebuild kit. Clean all passages with compressed air. Install new check balls in correct positions per service manual. Install rebuilt or new solenoid pack with new seals. Install new separator plate with gaskets. Reassemble valve body with all valves in correct orientation. Verify all valves move freely.
8. 8

   Reassemble clutch packs with new components
   Install new seals on all clutch pistons using assembly lube. Carefully install pistons into drums, ensuring seals are not damaged. Install return springs and compress with spring compressor tool. Install retaining snap rings, ensuring fully seated in grooves. Soak new friction plates in MERCON LV ATF for 15 minutes before installation. Install new steel and friction plates in correct order per service manual, alternating steel and friction. Install pressure plates and wave plates as specified. Install selective snap rings. Measure clutch pack clearance using feeler gauge and verify within specification (typically 0.030-0.050 inches depending on pack). Air check each clutch pack to verify piston operation and seal integrity.
9. 9

   Reassemble internal components into case
   Lubricate case bearing bores and bushings with assembly lube. Install new case bushings if worn. Install low/reverse clutch assembly with new seals. Install reverse clutch assembly. Install one-way clutches in correct orientation. Install reaction shaft and sun gear. Install planetary gear assemblies with correct thrust washers and bearings between components. Apply assembly lube to all thrust surfaces. Install intermediate clutch assembly. Install direct clutch assembly. Install forward clutch drum assembly. Verify all snap rings are fully seated. Measure total end play with dial indicator and verify within specification.
10. 10

    Install pump assembly and verify operation
    Install new pump seals and O-rings with assembly lube. Ensure pump drive gear is properly engaged with forward clutch. Install correct thickness selective thrust washer on pump. Carefully align pump and install into case, ensuring proper engagement. Install pump bolts and torque evenly in criss-cross pattern to specification. Verify pump rotates freely and input shaft has minimal end play. Install output shaft assembly with new seals and bearing. Install output shaft snap ring. Install extension housing with new gasket and torque bolts to specification.
11. 11

    Install valve body and transmission pan
    Position new separator plate with gaskets onto case. Install valve body assembly, ensuring manual valve engages with detent lever. Install valve body bolts in correct positions (note different lengths) and torque to specification in criss-cross pattern. Install new transmission filter. Connect solenoid pack electrical connector. Clean pan mating surface thoroughly. Install new pan gasket or apply RTV silicone bead as specified. Install transmission pan and torque pan bolts in criss-cross pattern starting from center working outward.
    Torque spec

    Pan Bolts20 Nm (15 lb-ft)
12. 12

    Install torque converter and prepare for installation
    Install new or rebuilt torque converter. Verify converter is fully seated by measuring depth from bellhousing face to converter hub (should be approximately 0.5-0.75 inches recessed). Rotate converter to ensure pump engagement. Apply small amount of high-temp grease to converter hub. Install transmission onto transmission jack. Verify all electrical connectors, cooler line fittings, and linkage components are accessible.
13. 13

    Install transmission into vehicle
    Raise transmission into position, ensuring torque converter remains fully engaged with pump. Align transmission to engine and carefully push forward until bellhousing contacts engine block. Install mounting bolts and torque to specification. Rotate engine and align torque converter to flexplate using alignment marks. Apply threadlocker to flexplate bolts. Install flywheel bolts in star pattern and torque to specification (note if TTY bolts, follow proper torque sequence). Install transmission crossmember and torque mounting bolts. Remove transmission jack and engine support. Install starter motor. Connect shift linkage and adjust as necessary. Connect all electrical connectors to transmission sensors and solenoid pack. Install transmission cooler lines with new O-rings.
    Torque spec

    Mounting Bolts76 Nm (56 lb-ft)

    Flywheel Bolts95 Nm (70 lb-ft)
14. 14

    Fill transmission and perform initial checks
    Install driveshaft, aligning marks made during removal. Torque driveshaft bolts to specification. Install transmission fill plug if removed. Add approximately 6 quarts of Motorcraft MERCON LV ATF through fill tube. Start engine and allow to idle. With foot on brake, shift through all gear ranges, pausing 3-5 seconds in each position. Return to Park. Check fluid level with engine running at operating temperature. Add fluid as necessary to bring to correct level on dipstick (typically requires 11 quarts total for complete rebuild). Check for leaks at all connections, pan, cooler lines, and pump seal area.
    Torque spec

    Fill Plug42 Nm (31 lb-ft)
15. 15

    Perform road test and transmission adaptation reset
    Connect scan tool and clear any DTCs. Perform transmission adaptation reset procedure using scan tool to allow TCM to relearn shift points. Road test vehicle in safe area, performing multiple acceleration and deceleration cycles through all gears. Monitor transmission operation for smooth shifts, proper gear engagement, and absence of slipping. Check for abnormal noises or vibrations. Return to shop and recheck fluid level with transmission at operating temperature. Check for leaks. Using scan tool, verify no DTCs present and review transmission data PIDs for proper operation. Verify shift solenoid operation, line pressure, and TFT sensor reading are within normal ranges.

Reassembly

1. Ensure all snap rings are fully seated in grooves and not twisted
2. Verify all thrust washers and bearings are in correct positions per service manual
3. Double-check clutch pack clearances are within specification before final assembly
4. Ensure valve body check balls are in correct positions - improper placement will cause shift problems
5. Verify torque converter is fully seated before transmission installation - insufficient engagement will damage pump
6. Install new crush washers on all drain plugs and new O-rings on cooler lines
7. Follow proper torque sequence for all critical fasteners including flywheel bolts and pan bolts

Verification

• Verify no transmission fluid leaks from pan, cooler lines, pump seal, or extension housing after test drive
• Confirm all forward gears (1-6) and reverse engage smoothly without slipping or harsh shifts
• Verify transmission shifts at appropriate RPM points under various throttle positions
• Check that transmission fluid is at correct level with engine at operating temperature in Park
• Confirm no DTCs present in TCM using scan tool
• Verify TFT sensor reads appropriate temperature (typically 160-200°F at operating temp)
• Check line pressure with scan tool is within specification for each gear range
• Confirm no abnormal noises such as whining, grinding, or rattling during operation
• Verify manual shifter operates smoothly through all gear positions with proper detent feel
• Perform 30-50 mile break-in drive and recheck fluid level and inspect for leaks

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