Complete removal, disassembly, rebuild, and reinstallation of the automatic transmission for a 2015 Kia Forte with 1.8L I4 engine, including internal component inspection and replacement.

Warnings

Tools required

Parts

• Automatic transmission overhaul kit × 1 — Use OEM specification for A6MF1 transmission
• Transmission filter × 1 — 463213B000
• Transmission pan gasket × 1 — Use OEM specification
• Torque converter seal × 1 — Use OEM specification
• Input shaft seal × 1 — Use OEM specification
• Output shaft seal × 1 — Use OEM specification
• Transmission mount × 1 — Inspect and replace if worn
• Transmission drain plug crush washer × 1 — Use OEM specification
• Axle seals × 2 — Both sides
• Thread locker (medium strength) × 1 — Loctite 242 or equivalent

Fluids

• Kia SP-IV-M ATF — 10 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable and secure away from battery post
3. Raise vehicle on lift or support securely on jack stands at all four corners
4. Remove both front wheels
5. Remove engine splash shields and undercovers
6. Install engine support fixture across engine bay to support engine weight
7. Prepare clean workspace with transmission assembly stand for rebuild procedures
8. Organize storage containers and label for small parts and components

Procedure

1. 1

   Drain transmission fluid and remove pan
   Place drain pan under transmission. Remove transmission drain plug and allow fluid to drain completely. Remove transmission pan bolts in criss-cross pattern and lower pan carefully. Remove and inspect transmission filter. Clean pan thoroughly and inspect for metal debris or clutch material which indicates internal wear patterns.
   ⚠Excessive metal debris in pan indicates severe internal wear. Document findings before proceeding.
   Torque spec

   Transmission Drain Plug30 Nm (22 lb-ft)

   Pan Bolts15 Nm (11 lb-ft)
2. 2

   Disconnect external components and wiring
   Disconnect transmission wiring harness connectors including range switch, speed sensors, and solenoid connector. Disconnect shift cable from transmission lever and remove cable bracket. Disconnect transmission cooler lines at transmission and plug openings to prevent contamination. Remove ground cables from transmission case.
   Torque spec

   Sensor Bolts10 Nm (8 lb-ft)
3. 3

   Remove axle shafts and driveshafts
   Remove axle shaft nuts at wheel hubs. Separate lower ball joints from steering knuckles. Using pry bar, carefully pry both axle shafts from transmission case, supporting shafts to prevent damage to CV joints. Plug transmission openings immediately with clean shop towels to prevent fluid loss and contamination.
4. 4

   Support and remove transmission
   Position transmission jack under transmission pan with adapter. Secure transmission to jack with safety chain. Remove starter motor. Remove bellhousing-to-engine mounting bolts. Remove transmission crossmember mounting bolts and lower crossmember. Verify all connections are disconnected. Carefully pull transmission straight back from engine, ensuring torque converter stays with transmission. Lower transmission on jack and move to clean workspace.
   ⚠️Ensure torque converter is fully seated in transmission and secured during removal to prevent it from falling.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
5. 5

   Mount transmission and remove external components
   Mount transmission on assembly stand. Remove torque converter and inspect for damage or excessive wear. Remove valve body cover screws and carefully remove valve body assembly, noting orientation and placement of all components. Remove solenoid pack and manual valve. Remove oil pump bolts and extract pump assembly.
   Torque spec

   Cover Screws10 Nm (8 lb-ft)
6. 6

   Disassemble transmission case
   Remove case bolts and carefully separate transmission case halves using plastic mallet if necessary. Remove snap rings securing internal components. Extract clutch packs, noting order and orientation. Remove planetary gear sets and shafts, keeping components organized by location. Inspect all bearings, thrust washers, and races for wear or damage.
   ℹ️Use dial indicator to measure end play of all shafts before disassembly. Record measurements for comparison during reassembly.
7. 7

   Inspect and measure all internal components
   Using micrometer and feeler gauges, measure all clutch plate thickness and check against service limits. Inspect all clutch plates for burning, glazing, or warping. Measure gear teeth for wear. Check all bearing surfaces for scoring or wear. Inspect all snap ring grooves. Check valve body passages for wear or scoring. Inspect all solenoids for proper operation. Replace any components outside specifications.
8. 8

   Clean and prepare components for reassembly
   Thoroughly clean all metal components with solvent and dry with compressed air. Clean all case passages and bolt holes. Remove all old gasket material from mating surfaces. Install new seals on all shafts and bores using appropriate seal drivers. Soak new clutch plates in SP-IV-M ATF for minimum 30 minutes before installation.
   ⚠Ensure all passages and components are completely dry before applying new ATF during assembly. Residual solvent will contaminate fluid.
9. 9

   Reassemble internal components
   Coat all components with clean SP-IV-M ATF during assembly. Install thrust washers in correct positions with petroleum jelly to hold in place. Assemble planetary gear sets with new bearings and install into case. Install clutch packs in correct order with proper clutch plate count per pack. Install snap rings ensuring full engagement in grooves. Use clutch spring compressor for clutch pack snap rings. Verify proper end play with dial indicator per service specifications.
10. 10

    Assemble transmission case halves
    Apply new gasket or appropriate RTV sealant to case mating surface per service manual specifications. Carefully align and join case halves ensuring all components remain properly positioned. Install case bolts and torque in criss-cross pattern. Verify shafts rotate freely without binding. Install oil pump with new seal and torque pump bolts to specification.
    Torque spec

    Pan Bolts15 Nm (11 lb-ft)
11. 11

    Install valve body and external components
    Install new transmission filter. Install manual valve in correct position. Install solenoid pack with new seals, ensuring proper alignment. Install valve body assembly with new gasket, verifying all passages align correctly. Install valve body cover screws and torque to specification. Install new torque converter seal in transmission front cover.
    Torque spec

    Cover Screws10 Nm (8 lb-ft)

    Sensor Bolts10 Nm (8 lb-ft)
12. 12

    Reinstall transmission in vehicle
    Apply small amount of grease to torque converter pilot hub. Verify torque converter is fully seated in transmission (measure depth to verify proper engagement with oil pump). Lift transmission into position with transmission jack. Align transmission to engine and guide onto dowel pins. Install bellhousing mounting bolts and torque to specification in star pattern. Install transmission crossmember and mounting bolts, then torque to specification.
    ⚠Torque converter must be fully seated before mating transmission to engine. Verify at least 3 distinct clicks when seating converter.
    Torque spec

    Mounting Bolts26 Nm (19 lb-ft)
13. 13

    Reconnect driveline and external components
    Install new axle seals in transmission. Install axle shafts ensuring positive engagement with differential side gears. Reconnect lower ball joints and torque to specification. Install axle shaft nuts and torque to specification. Install starter motor. Reconnect transmission cooler lines with new O-rings if equipped. Install shift cable and adjust per service procedure. Reconnect all electrical connectors.
14. 14

    Install transmission pan and fill with fluid
    Install new transmission pan gasket. Install transmission pan and torque pan bolts in criss-cross pattern. Install new crush washer on drain plug and install drain plug, torquing to specification. Using fluid pump, add approximately 5 quarts of SP-IV-M ATF through dipstick tube or fill port. Start engine and add remaining fluid while cycling through all gear ranges.
    ℹ️Transmission must be at operating temperature (160-175°F) for accurate fluid level check. Add fluid in small increments to avoid overfilling.
    Torque spec

    Pan Bolts15 Nm (11 lb-ft)

    Transmission Drain Plug30 Nm (22 lb-ft)
15. 15

    Perform final checks and road test
    With engine at idle and transmission in Park, verify no leaks at pan, cooler lines, axle seals, or case mating surfaces. Check fluid level with engine at operating temperature and adjust as needed. Remove engine support fixture. Install wheels and torque lug nuts. Install splash shields and undercovers. Clear any stored diagnostic codes. Perform road test verifying smooth shifts in all gears, proper engagement, no slipping, and no abnormal noises.

Reassembly

1. Reassembly follows disassembly steps in reverse order with attention to proper component orientation
2. All seals, gaskets, and clutch plates must be replaced with new components from overhaul kit
3. Apply thread locker to case bolts and other critical fasteners as specified in service manual
4. Verify all snap rings are fully seated in grooves and properly positioned
5. Torque all fasteners to specification using star or criss-cross pattern where indicated

Verification

• Check transmission fluid level with engine at operating temperature and transmission in Park
• Verify no fluid leaks from pan, seals, cooler lines, or case
• Confirm smooth shifts through all gear ranges with no slipping or harsh engagement
• Verify speedometer and gear position indicator function correctly
• Road test vehicle through multiple drive cycles to confirm proper operation under various loads
• Check for any stored diagnostic trouble codes and clear if related to transmission disconnection
• Re-check fluid level after road test and top off if necessary
• Inspect for leaks again after road test while transmission is at operating temperature

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