2021-2023 Jeep Wrangler D Clutch Repair TSB 21-039-24

Symptoms

Owners of affected vehicles may observe a Malfunction Indicator Lamp (MIL) illuminating on the dashboard. This typically indicates an issue with the vehicle's powertrain system. Further investigation by a technician may reveal specific Diagnostic Trouble Codes (DTCs) related to the transmission's D clutch.

Fault Codes (DTCs)

When the Malfunction Indicator Lamp (MIL) illuminates, technicians may find one or more of the following Diagnostic Trouble Codes (DTCs) stored in the vehicle's system:

Code	Description
P0733-00	Gear 3 Shift Incorrect Ratio
P1DA8-00	Incorrect Gear Ratio Clutch A B or D Defective
P1D92-00	Incorrect Gear Ratio - Clutch 4 Defective

These codes specifically point to issues within the transmission's gear ratio and clutch operation, necessitating a D clutch repair.

Diagnosis

If a customer reports a Malfunction Indicator Lamp (MIL) illumination, a technician should first check for the presence of DTCs P0733-00, P1DA8-00, or P1D92-00. If these codes are present, the next step involves performing a pressure check of the D clutch circuit using procedures available in DealerCONNECT. This diagnostic step helps confirm the D clutch as the source of the transmission issue in your 2021 Jeep Wrangler.

Repair Procedure Summary

The core of Technical Service Bulletin (TSB) 21-039-24 involves replacing the D clutch within the Eight-Speed Auto 850RE Transmission. The repair is extensive and requires significant disassembly and reassembly of the transmission components. Here's a summary of the key steps:

1. Initial Disassembly: The procedure begins with checking for the specified DTCs and performing a D clutch circuit pressure check. If confirmed, the transmission is removed from the vehicle, followed by the torque converter. Depending on the vehicle's drivetrain (4WD or 2WD), the extension housing, output shaft seal, output shaft snap ring, and output shaft flange locknut are removed. The transmission oil pan and gasket are also removed.
2. Internal Component Removal: Technicians then proceed to disconnect the Hydraulic Impulse Oil Storage (H.I.S.) connector and remove the valve body assembly. The Output Speed Sensor (OSS) and electrical harness insulator are carefully removed using specialized tools like Guide Sleeve 10377. The fluid port, fluid transfer tube O-rings, and input shaft O-ring are extracted, followed by the oil pump housing.
3. D Clutch Pack Access: To reach the D clutch, the D clutch spring damper and park pawl lock rod are removed. The input/output shaft and P4 annulus drum assembly are then taken out of the transmission case. The D clutch pack is disassembled, which involves removing the P1 annulus/B clutch hub assembly, thrust bearing, holding plate, snap ring, P1 planetary carrier, P2 annulus/P3 sun gear, and the D clutch drum. Special tools such as Press Fixture 8925-3, Bearing/Gear 1130, and Rings, Support 10378 are utilized during this phase.
4. D Clutch Pack Reassembly: A new P4 planetary carrier/output shaft lock ring is installed, followed by the D clutch drum, P2 annulus/P3 sun gear, thrust bearing, and the input shaft with P2 planetary carrier. The snap ring, thrust bearing, holding plate, selectable shim, and P1 annulus/D clutch hub assembly are reinstalled. Finally, the new D clutch discs and plates are installed, and the snap ring is secured.
5. Transmission Reassembly: The input/output shaft and P4 annulus drum assembly are reinstalled into the case. The park pawl lock rod and D clutch damper spring are positioned. The oil pump housing, a new input shaft O-ring, and the transmission oil pump assembly are carefully reinstalled. The Manual Park Release (MPR) lever is temporarily adjusted to ease the installation of the valve body assembly. New fluid transfer tube O-rings are installed, and the valve body assembly is secured, ensuring proper alignment of the shift fork. The electrical harness guide sleeve (using Guide Sleeve 10377) and Output Speed Sensor are reinstalled with careful attention to pin alignment. The H.I.S. and transmission oil pan with a new gasket are reattached. A new output shaft seal is positioned flush with the case.
6. Final Steps: For 4X4 vehicles, the extension housing is reinstalled, and for 2WD vehicles, the output flange is addressed with a new output shaft flange nut. The torque converter is installed. Before installing the transmission back into the vehicle, it must be pre-filled with the specified transmission fluid. After installation, a wiTECH Quick Learn Procedure is performed, and any stored DTCs are cleared.

This comprehensive process ensures the proper functioning of the D clutch and resolves the transmission-related issues in your 2021 Jeep Wrangler.

Required Tools and Parts

To perform the D clutch repair, specific parts and special tools are necessary:

Parts:

• D Clutch Repair Kits:
  • 68676890AA (4x4 JL, JT, WD, WK)
  • 68676891AA (4x4 WL)
  • 68676887AA (4x4 DS, DT, DX, WS)
  • 68239499AC (AWD LA, LD, LX)
  • 68676892AA (RWD LA, LD, LX)
  • 68676894AA (RWD WD, WK)
  • 68676893AA (RWD DS, DT, DX, WS)
• Automatic Transmission Fluid: 68218925AB

Special Tools/Equipment:

• Guide Sleeve: 10377
• Press Fixture: 8925-3
• Bearing/Gear: 1130
• Rings, Support: 10378

Important Warnings

Owners and technicians should be aware of several critical warnings and notes related to this repair:

• Transmission Control Module (TCM) / Transmission Control Module Assembly (TCMA) Sensitivity: "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."
• Unique Transmission Fluid: "CAUTION!! A unique transmission fluid has been developed for this transmission. This fluid is NOT compatible with ATF+4 or any other current FCA US LLC transmission fluid. For specifics about this unique fluid see FLUIDS, LUBRICANTS AND GENUINE PARTS."
• TCM Adaptation Procedure: "NOTE: If the transmission is being reconditioned (clutch/seal replacement) or replaced, it is necessary to perform the TCM Adaptation Procedure (Refer to 08 - Electrical/8E - Electronic Control Modules/Module, Transmission Control/ Module Programming)."
• Transmission Positioning: "NOTE: The transmission must be in a vertical position before the main stack is removed, so damage to the drums do not occur." This note is repeated for installation as well, emphasizing its importance.
• Output Shaft Seal Installation: "CAUTION!! The seal must be installed flush with the case. Driving the seal deeper could damage the seal causing a leak."
• Shift Fork Alignment: During valve body assembly installation, "NOTE: Make sure the shift fork lines up properly."

Owner Action

If your 2021-2023 Jeep Wrangler or other affected Stellantis vehicle is exhibiting a Malfunction Indicator Lamp (MIL) illumination and Diagnostic Trouble Codes P0733-00, P1DA8-00, or P1D92-00, it is recommended to schedule an appointment with an authorized dealer. The dealer will diagnose the issue and perform the necessary D clutch repair as outlined in TSB 21-039-24. This repair is reimbursable within the provisions of the vehicle's warranty.

Source: NHTSA ID 11001310.