FixVault
Home › Jeep › 2021 › Grand Cherokee SRT › Repair and Diagnosis › Transmission › Transmission Control Systems › 8HP70 Automatic Transmission (Service Information) › Disassembly

8HP70 Automatic Transmission (Service Information): Disassembly

CAUTION:

The Transmission Control Module (TCM), or Transmission Control Module Assembly (TCMA) is extremely sensitive to Electrostatic Discharge (ESD). Always use a ground strap and follow the ESD guidelines in ELECTROSTATIC DISCHARGE SENSITIVE DEVICES. Failure to follow these instructions may result in damage to the TCM/TCMA.

NOTE:

If the transmission is being reconditioned (clutch/seal replacement) or replaced, it is necessary to perform the TCM Adaptation Procedure. Refer to 8HP70 TCM PROGRAMMING PROCEDURE .

NOTE:

Tag all clutch pack assemblies, as they are removed, for reassembly identification.

GC0152102Courtesy of CHRYSLER GROUP, LLC
NOTE:

Rear Wheel Drive (RWD) shown, All Wheel Drive (AWD) similar.

  1. Remove the torque converter (1).
    GC0152264Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    AWD only.

  2. Remove the transmission housing extension bolts (2) and remove the housing (1).
  3. Remove the transmission rear oil seal (3) with a suitable slide hammer and screw.
    GC0152265Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    AWD only.

  4. Remove the output shaft snap ring (1) and washer.
    GC0152101Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    RWD only.

  5. Using a suitable punch, remove the staking from the driveshaft flange nut, and loosen the nut about 1 thread using a 34 mm 12 point socket (3) and (special tool #C-3281, Holder, Flange) (2) to hold the flange (1).
    GC0152257Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    RWD shown, AWD similar.

    NOTE:

    End play specification is between 0.11 - 0.42 mm (0.0043 - 0.0165 in.). If end play is outside this range, a different selectable end play shim must be used during assembly.

  6. Measure the output shaft (1) end play as follows:
    1. Attach a dial indicator (2) and position the plunger against the end of the output shaft (1).
    2. Zero the dial indicator (2).
    3. Move the output shaft (1) in and out, and record the maximum travel for assembly reference.
    GC0152116Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    RWD only.

  7. Finish removing the driveshaft flange nut.
  8. Remove the transmission rear dust seal (2).
  9. Remove the driveshaft flange (1).
  10. Remove the transmission rear oil seal (3) with a suitable slide hammer and screw.
  11. Remove the transmission output shaft washer.
    GC0152099Courtesy of CHRYSLER GROUP, LLC
  12. Remove the oil pan retaining bolts (2).
    NOTE:

    Inspect the gasket for reuse. If the seal is cut or torn, replace the gasket.

  13. Carefully detach the oil pan (1) and gasket.
    GC0154626Courtesy of CHRYSLER GROUP, LLC
  14. If equipped, disconnect the Hydraulic Impulse Storage (HIS) accumulator wire harness connector. Remove the three screws (2 and 3) and the accumulator (1).
    GC0152103Courtesy of CHRYSLER GROUP, LLC
  15. Remove the valve body assembly end retainer bolts (3).
  16. Lift the wire harness connector lock (2) to release the internal harness end from inside the transmission for valve body assembly removal.
  17. Remove the output speed sensor bolt (1) and pull the sensor (4) loose from the case and clip it onto holder.
    GC0152117Courtesy of CHRYSLER GROUP, LLC
  18. Using the (special tool #10377, Remover/Installer, Guide Sleeve) (1) carefully pull the wire harness insulator (2) straight out from the transmission case (3).
    GC0169780Courtesy of CHRYSLER GROUP, LLC
  19. Remove valve body assembly retaining bolts 1-14 (15-18 are already removed).
  20. Carefully lift the valve body assembly from the transmission.
    GC0152241Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    The fluid port (1) may be in the transmission or the valve body assembly.

  21. Pull the fluid port (1) from the transmission or valve body assembly.
  22. Remove the two O-rings (2).
  23. Remove the compression seal (3) from the transmission.
    GC0154667Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    Discard oil pump housing retaining bolts after removal. Bolts are a one time use.

  24. Remove and DISCARD  the oil pump housing bolts (1).
    GC0152105Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    Remove the input shaft O-ring before the oil pump is removed.

  25. Remove the input shaft O-ring (1) using a small pick (2) or equivalent.
    GC0154661Courtesy of CHRYSLER GROUP, LLC
  26. Carefully pry the oil pump housing (2) away from the case with a small flat blade screwdriver (1) or equivalent through the case opening.
  27. From the front of the transmission, remove the oil pump housing.
    GC0152249Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    Apply air pressure slowly because oil may spray when B-piston releases from the assembly.

  28. With one hand above B-piston (1), carefully apply air pressure into the hole (2) directly above the B-piston alignment tab (3) to remove B-piston (1) from the assembly.
    GC0152250Courtesy of CHRYSLER GROUP, LLC
  29. Remove the outer ring (1) (under B-piston).
  30. Remove the snap ring (2).
  31. Remove the clutches and spacers (4).
  32. Remove the hub (3).
    GC0152251Courtesy of CHRYSLER GROUP, LLC
  33. Position the oil pump housing assembly (4) in a suitable arbor press.
  34. Using the (special tool #8285, Compressor, Spring) (1), press on the fingers of the A-piston retaining ring to remove tension, and remove the two halves of the split retainer ring (2, 3).
    GC0152254Courtesy of CHRYSLER GROUP, LLC
  35. Remove the belleville spring (1) and plate.
    GC0154658Courtesy of CHRYSLER GROUP, LLC
  36. Remove the clutch A piston (1) and seal (2) from the oil pump assembly.
    GC0154629Courtesy of CHRYSLER GROUP, LLC
  37. Remove the inner (1) and outer (2) oil pump O-rings.
    GC0154464Courtesy of CHRYSLER GROUP, LLC
  38. Remove the bolts (1) from the oil pump.
    GC0154370Courtesy of CHRYSLER GROUP, LLC
  39. Separate the two halves of the oil pump, by pushing on the hub.
    GC0152247Courtesy of CHRYSLER GROUP, LLC
  40. Using the (special tool #9667, Remover, Seal) (2) and the (special tool #C-3752, Slide Hammers) (1), remove the oil seal from the front pump cover.
    GC0152248Courtesy of CHRYSLER GROUP, LLC
  41. Remove the snap ring from the front cover (3).
  42. Using the (special tool #6787A, Remover, Bearing Cup) (1) and the (special tool #C-3752, Slide Hammers) (2) remove the needle bearing from the front cover (3).
  43. Remove the snap ring from the oil pump housing.
  44. Using the (special tool #9585, Remover, Bearing Cup) and the (special tool #C-637, Slide Hammer, Universal) remove the needle bearing from the oil pump housing.
    GC0152243Courtesy of CHRYSLER GROUP, LLC
  45. Remove the Manual Park Release (MPR) lever retaining nut (2) and remove the lever (1).
    GC0152140Courtesy of CHRYSLER GROUP, LLC
  46. Remove the park pawl lock rod guide plate retaining screws (1) and remove the plate (2).
    GC0152141Courtesy of CHRYSLER GROUP, LLC
  47. Remove the park pawl lock rod (1) from the fork (2).
    GC0152142Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    Pay attention to the spring position for installation.

  48. Remove the roll pin from the selector shaft (4) using a suitable pin punch (3).
  49. Remove the shaft (4), spring (2) and fork (1) from the case.
  50. Remove the MPR shaft seal using a small screwdriver or equivalent.
    GC0152143Courtesy of CHRYSLER GROUP, LLC
  51. Remove the park pawl shaft plug (1) from the rear of the case.
    GC0152144Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    Pay attention to the spring position for installation.

  52. Remove the park pawl shaft using a suitable pin punch (3), remove the park pawl (1) and spring (2).
    GC0154476Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    The transmission must be in the upright position to remove the assembly to avoid damage to the drums.

  53. Remove the input/output shaft and P4 annulus drum assembly (1) from the case.
    GC0162428Courtesy of CHRYSLER GROUP, LLC
  54. Using the (special tool #8912, Remover, Bearing) (3) and the (special tool #C-637, Slide Hammer, Universal) (2) remove the output seal (1).
    GC0152266Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    AWD shown, RWD similar. The AWD bearing is a needle bearing and the RWD is a ball bearing.

  55. Remove the outer bearing snap ring (1), and the outer bearing (2).
    GC0152267Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    AWD shown, RWD similar.

  56. Remove the oil dam snap ring.
  57. Using the (special tool #9664, Remover, Bearing Cup) (1) and the (special tool #C-637, Slide Hammer, Universal) (2), remove the oil dam (3).
    GC0152269Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    AWD shown, RWD similar. The AWD bearing is a needle bearing and the RWD is a ball bearing.

  58. Remove the output shaft inner bearing snap ring.
    NOTE:

    AWD shown, RWD similar.

  59. Using the (special tool #9664, Remover, Bearing Cup) (1) and the (special tool #C-637, Slide Hammer, Universal) (2), remove the inner bearing (3).
    GC0152139Courtesy of CHRYSLER GROUP, LLC
  60. Position the input/output shaft and P4 annulus drum assembly (1) on (special tool #8925-3, Assembly, Press Fixture) (3) and (special tool #1130, Splitter, Bearing/Gear) (4).
  61. Remove the B clutch pack (2).
    GC0152146Courtesy of CHRYSLER GROUP, LLC
  62. Remove the O-ring and 5 squared O-rings.
  63. Remove the P1 annulus/B clutch hub assembly (1) from the P4 annulus drum.
    NOTE:

    The selectable shim may stick to the bottom of the P1 annulus/B clutch hub assembly (1).

  64. Remove the selectable shim from the P1 annulus/B clutch hub.
  65. Remove the needle bearing and holding plate (2) from the P1 planetary carrier.
    GC0152147Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    The (special tool #10378, Rings, Support) are three pieces intended to be used in multiple locations around the drum.

  66. Position the (special tool #10378, Rings, Support) (1) on the P4 annulus drum assembly to protect the drum.
    NOTE:

    Pry the snap ring from the opposite side of the snap ring openings to release.

    NOTE:

    When the snap ring is removed the internal clutch drum may drop slightly.

  67. Using a suitable tool (3), release the snap ring (2) by prying in and up from the opposite side of the snap ring openings.
    GC0152148Courtesy of CHRYSLER GROUP, LLC
  68. Remove the P1 planetary carrier (3).
    GC0154685Courtesy of CHRYSLER GROUP, LLC
  69. Remove P1/P2 sun gear (1).
    GC0152150Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    Be careful not to damage the P2 carrier magnetic pick up for the input sensor.

  70. Remove the input shaft with P2 planetary carrier (1) from the drum assembly.
  71. Remove the needle bearing (2) and washer.
    GC0152151Courtesy of CHRYSLER GROUP, LLC
  72. Remove the P2 annulus/P3 sun gear (1) from the drum assembly (2).
    GC0152172Courtesy of CHRYSLER GROUP, LLC
  73. Remove the D clutch drum (1) from the P4 annulus drum (2).
    GC0152152Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    The (special tool #10378, Rings, Support) are three pieces intended to be used in multiple locations around the drum.

  74. Position the (special tool #10378, Rings, Support) (4) on the P4 annulus drum assembly to protect the drum.
  75. Using a suitable tool (1), release and remove the snap ring (2).
  76. Remove the P3 planetary carrier (3).
  77. Remove the needle bearing from the planetary carrier.
    GC0152170Courtesy of CHRYSLER GROUP, LLC
  78. Remove the P4 sun gear/C/E clutch retainer (1) from the D clutch drum (2).
    GC0152173Courtesy of CHRYSLER GROUP, LLC
  79. Remove the snap ring (1) from the P4 sun gear/C/E clutch retainer (2).
    GC0152174Courtesy of CHRYSLER GROUP, LLC
  80. Remove the P3 annulus (1) from the P4 sun gear/C/E clutch retainer (2).
    GC0152175Courtesy of CHRYSLER GROUP, LLC
  81. Remove the snap ring (1) from the P4 sun gear/C/E clutch retainer (2).
    GC0152176Courtesy of CHRYSLER GROUP, LLC
  82. Remove the E clutch (1) from the P4 sun gear/C/E clutch retainer (3).
  83. Remove the needle bearing (2) from the E clutch (1).
    GC0152177Courtesy of CHRYSLER GROUP, LLC
    NOTE:

    The E clutch and C clutch are similar. The C clutch hub is removable and has 6 friction plates.

  84. Remove the C clutch (1) from the P4 sun gear/C/E clutch retainer (2).
  85. Remove the bearing from top and bottom of C clutch (1).
    GC0152270Courtesy of CHRYSLER GROUP, LLC
  86. Remove the P4 planetary carrier/output shaft (2) from the P4 annulus drum (1).
    GC0152178Courtesy of CHRYSLER GROUP, LLC
  87. Remove the snap ring (1) from the P4 annulus drum (2).
  88. Remove the P4 annulus (3) from the P4 annulus drum (2).
About FixVault