Disassembly of the F4A4A1N2Z automatic transmission

Important warnings

  • The automatic transmission (AT) design contains numerous precision parts. Handle them with extreme care — avoid scratches and other damage during disassembly and assembly.
  • The workbench must be covered with a rubber mat and kept clean.
  • During disassembly, fabric gloves and rags are prohibited. Only nylon cloth or paper towels are permitted.
  • All removed parts must be thoroughly washed:
    • metal components — in solvent, then dried with a jet of compressed air;
    • friction discs of clutches and brakes, plastic thrust plates and rubber elements — in automatic transmission fluid (ATF). After washing, store them in a clean place.
  • If any faults are found, be sure to disassemble and clean the AT heat exchanger circuit.

Materials used and precautions:

  • For washing metal parts, use clean solvent and compressed air; for friction discs, plastic and rubber elements — only ATF.
  • Do not reuse gaskets, O-rings or oil seals — replace them with new ones.
  • For lubrication and retention of components, use blue petrolatum or white petroleum jelly.
  • Before installing friction elements, soak them in ATF for at least 2 hours.
  • Do not apply sealant/adhesive to gaskets.
  • When replacing bushes, install the assembly as a complete unit.

Disassembly procedure

1. Removing the torque converter

Remove the torque converter.

Removing the torque converter
Fig. 1. Removing the torque converter

2–5. Measuring clearance and removing auxiliary elements

  • Using a dial indicator, measure the input shaft axial clearance.
  • Remove all brackets.
  • Withdraw the dipstick.
  • Remove the heat exchanger inlet pipe.

6. Removing the improved breather

Remove the improved breather.

Removing the breather
Fig. 2. Removing the improved breather

7–9. Removing the sensors and selector lever

  • Remove the input and output shaft speed sensors.
  • Before removing the valve body, be sure to loosen the selector lever mounting nut (ignoring this order may damage the selector switch).
Selector lever mounting nut
Fig. 3. Selector lever mounting nut

Remove the selector lever, then the selector switch.

Removing the selector lever and switch
Fig. 4. Removing the selector lever and selector switch

10–11. Removing the seal cap and valve body cover

Remove the seal cap.

Removing the seal cap
Fig. 5. Removing the seal cap

Remove the valve body cover.

Removing the valve body cover
Fig. 6. Removing the valve body cover

12. Removing the selector lever shaft stop

Remove the selector lever shaft stop.

Removing the selector lever shaft stop
Fig. 7. Removing the selector lever shaft stop

13–15. Removing the valve body

  • Remove the coolant temperature sensor, disconnect all connectors and take the solenoid valve electrical cable off the valve body.
  • Loosen the valve body mounting bolts (26 pcs). Be careful — do not lose the 2 steel balls.
Location of the valve body mounting bolts
Fig. 8. Location of the valve body mounting bolts
Removing the valve body
Fig. 9. Removing the valve body

Remove the valve body, gasket and 2 steel balls.

Valve body, gasket and steel balls
Fig. 10. Valve body, gasket and 2 steel balls

16. Removing the electrical connector

Remove the snap ring from the electrical connector, then push the connector into the transmission case to take out the solenoid valve electrical cable.

Removing the electrical connector
Fig. 11. Removing the electrical connector

17. Removing the strainer and oil seal

Remove the strainer and the auxiliary brake housing oil seal.

Removing the strainer and oil seal
Fig. 12. Removing the strainer and oil seal

18. Removing the accumulator pistons and springs

Remove the accumulator pistons and springs. Be sure to mark them for correct subsequent installation.

Accumulator pistons and springs
Fig. 13. Accumulator pistons and springs

19–20. Removing the roller, selector lever shaft and lock rod

  • Remove the selector lever shaft roller.
  • Remove the selector lever shaft and the output shaft lock rod.
Removing the selector lever shaft and lock rod
Fig. 14. Removing the selector lever shaft and lock rod

21. Removing the converter housing

After loosening the mounting bolts, remove the torque converter housing.

Removing the converter housing
Fig. 15. Removing the torque converter housing

22. Removing the O-rings

Remove the 2 O-rings.

Removing two O-rings
Fig. 16. Removing the 2 O-rings

23. Removing the differential and adjusting ring

Remove the differential and adjusting ring.

Removing the differential and adjusting ring
Fig. 17. Removing the differential and adjusting ring

24. Removing the working fluid filter

Remove the working fluid filter.

Removing the working fluid filter
Fig. 18. Removing the working fluid filter

25–27. Removing the working fluid pump

Loosen the working fluid pump mounting bolts.

Working fluid pump mounting bolts
Fig. 19. Working fluid pump mounting bolts
  • Using the pump puller (MD998333), remove the pump — screw in the pullers evenly as shown in the figure.
  • Remove the working fluid pump gasket.
Removing the pump with the puller
Fig. 20. Removing the working fluid pump with puller MD998333

28. Removing thrust washer No. 1

Remove thrust washer No. 1.

Removing thrust washer No. 1
Fig. 21. Removing thrust washer No. 1

29. Removing the input shaft with clutch

Grasp the input shaft and remove it together with the low clutch.

Removing the input shaft with clutch
Fig. 22. Removing the input shaft with the low clutch

30. Removing thrust bearing No. 2

Remove thrust bearing No. 2.

Removing thrust bearing No. 2
Fig. 23. Removing thrust bearing No. 2

31. Removing the clutch hub

Remove the low clutch hub.

Removing the clutch hub
Fig. 24. Removing the low clutch hub

32. Removing the lock shaft, adjusting ring and spring

Withdraw the output shaft lock shaft, then remove the adjusting ring and spring.

Removing the lock shaft and spring
Fig. 25. Removing the lock shaft, adjusting ring and spring

33. Removing the output shaft lock and support

Remove the 2 shafts of the output shaft lock support, then the output shaft lock and support.

Removing the output shaft lock and support
Fig. 26. Removing the output shaft lock and support

34–37. Removing the rear cover and bearings

  • Remove the rear cover.
  • Remove the outer race of thrust bearing No. 8.
  • Remove the 4 O-rings.
  • Remove the input shaft rear bearing.
Removing the rear cover
Fig. 27. Removing the rear cover
Removing the input shaft rear bearing
Fig. 28. Removing the input shaft rear bearing

38. Removing the clutch and thrust bearing No. 7

Remove the reverse and overdrive clutch, as well as thrust bearing No. 7.

Removing the clutch and thrust bearing No. 7
Fig. 29. Removing the clutch and thrust bearing No. 7

39. Removing the hub and thrust bearing No. 6

Remove the overdrive clutch hub and thrust bearing No. 6.

Removing the hub and thrust bearing No. 6
Fig. 30. Removing the hub and thrust bearing No. 6

40. Removing thrust bearing No. 5

Remove thrust bearing No. 5.

Removing thrust bearing No. 5
Fig. 31. Removing thrust bearing No. 5

41. Removing the reverse sun gear

Remove the reverse sun gear.

Removing the reverse sun gear
Fig. 32. Removing the reverse sun gear

42. Removing the snap ring

Remove the snap ring.

Removing the snap ring
Fig. 33. Removing the snap ring

43. Removing the auxiliary brake and return spring

Remove the auxiliary brake and return spring.

Removing the auxiliary brake and return spring
Fig. 34. Removing the auxiliary brake and return spring

44. Removing the pressure disc and brake discs

Remove the pressure disc, 2 friction discs and the brake steel disc.

Removing the pressure disc and brake discs
Fig. 35. Removing the pressure disc and brake discs

45. Removing the carrier assembly

Remove the carrier assembly.

Removing the carrier assembly
Fig. 36. Removing the carrier assembly

46. Removing the snap ring

Remove the snap ring.

Removing the carrier snap ring
Fig. 37. Removing the snap ring

47. Removing the reaction plate and brake disc

Remove the reaction plate and brake disc.

Removing the reaction plate and brake disc
Fig. 38. Removing the reaction plate and brake disc

48. Removing the snap ring

Remove the snap ring.

Removing the reaction plate snap ring
Fig. 39. Removing the snap ring

49. Removing the steel and friction discs

Remove the 3 steel discs, 4 friction discs and the brake pressure disc.

Removing the steel and friction discs
Fig. 40. Removing the steel and friction discs

50. Removing the spring ring

Remove the spring ring.

Removing the spring ring
Fig. 41. Removing the spring ring

51–52. Removing the one-way clutch inner ring and brake

  • Using a special tool, press down on the one-way clutch inner ring and remove the snap ring.
  • Remove the one-way clutch inner ring, seal ring, spring retainer, return spring and the low/reverse engagement brake.
Removing the one-way clutch inner ring
Fig. 42. Removing the one-way clutch inner ring and brake

53. Loosening the drive gear bolts

Loosen 3–4 mounting bolts of the intermediate drive gear. Turn the gear 1/8 turn (45°), then loosen the remaining 3–4 bolts.

Loosening the drive gear bolts
Fig. 43. Loosening the drive gear bolts

54. Removing the intermediate drive gear

Remove the intermediate drive gear.

Removing the intermediate drive gear
Fig. 44. Removing the intermediate drive gear

55. Removing the cap

Remove the cap.

Removing the cap
Fig. 45. Removing the cap

56. Bending back the lock nut tab

Bend back the tab securing the output shaft lock nut (the nut has a left-hand thread).

Bending back the lock nut tab
Fig. 46. Bending back the lock nut tab

57. Loosening the output shaft lock nut

Using the special tool (socket MB991625 and spanner socket MB990607), loosen the output shaft lock nut.

Loosening the output shaft lock nut
Fig. 47. Loosening the output shaft lock nut

58. Loosening the bearing separator bolts

Loosen the bearing separator mounting bolts.

Loosening the bearing separator bolts
Fig. 48. Loosening the bearing separator bolts

59. Removing the output shaft with bearing

By striking the end of the output shaft, remove it together with the tapered roller bearing.

Removing the output shaft with bearing
Fig. 49. Removing the output shaft with the tapered roller bearing

60–61. Removing the adjusting ring and snap ring

  • Remove the adjusting ring and the bearing outer race.
  • Remove the snap ring.
Removing the adjusting ring and snap ring
Fig. 50. Removing the adjusting ring and snap ring