2021-2023 Stellantis 850RE Transmission D Clutch Repair TSB

Stellantis has issued Technical Service Bulletin (TSB) 21-039-24 REV. A to address a condition where certain 2021-2023 vehicles equipped with the Eight-Speed Auto 850RE Transmission (Sales Code DFT) may illuminate the Malfunction Indicator Lamp (MIL). This TSB, dated June 14, 2024, supersedes the previous TSB 21-039-24 issued on May 25, 2024, and includes an updated repair procedure. The core of the issue points to a problem with the D clutch within the transmission, leading to specific diagnostic trouble codes.

Symptoms

Owners of affected vehicles may notice the Malfunction Indicator Lamp (MIL) illuminating on their dashboard. This warning light indicates a detected issue within the vehicle's powertrain system. Upon further investigation by a technician, specific Diagnostic Trouble Codes (DTCs) related to transmission gear ratio errors are typically found.

Fault Codes / DTCs

Technicians investigating the MIL illumination 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 with gear ratios and the D clutch within the Eight-Speed Auto 850RE Transmission.

Diagnosis / Trigger Conditions

If a customer reports MIL illumination and associated symptoms, a technician will 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 on the D clutch circuit using the dealer connect procedure. This diagnostic step helps confirm if the D clutch is indeed failing and requires replacement, which is the focus of this TSB for the Jeep Wrangler D clutch repair.

Important Warnings

Stellantis TSB 21-039-24 includes several critical warnings for technicians to ensure proper repair and prevent further damage:

• Electrostatic Discharge (ESD) Sensitivity: The Transmission Control Module (TCM) or Transmission Control Module Assembly (TCMA) is extremely sensitive to ESD. Technicians must always use a ground strap and adhere to ESD guidelines for sensitive devices to prevent damage to the TCM/TCMA.
• Transmission Fluid Compatibility: A unique transmission fluid has been developed specifically for this transmission. This fluid is NOT compatible with ATF+4 or any other current FCA US LLC transmission fluid. Technicians must consult the FLUIDS, LUBRICANTS AND GENUINE PARTS information for specifics on the correct fluid.
• TCM Adaptation Procedure: If the transmission undergoes reconditioning (e.g., clutch or seal replacement) or is replaced entirely, it is mandatory to perform the TCM Adaptation Procedure. This procedure is detailed in the DealerCONNECT/Service Library under 'Service Info>08 - Electrical/8E - Electronic Control Modules/Module, Transmission Control/ Module Programming'.
• Transmission Positioning: During the repair, the transmission must be placed in a vertical position before the main stack is removed. Failure to do so can cause damage to the internal drums.
• Gasket Inspection: When removing the transmission oil pan, the gasket should be inspected for reuse. If the seal is cut or torn, it must be replaced.
• Input Shaft O-ring: The input shaft O-ring must be removed before the oil pump is removed.
• Output Shaft Seal Installation: The new output shaft seal must be installed flush with the case. Driving the seal deeper could damage it and lead to a leak.

Repair Procedure Summary

The repair outlined in TSB 21-039-24 involves replacing the D clutch within the Eight-Speed Auto 850RE Transmission. This is a comprehensive procedure requiring significant disassembly and reassembly of the transmission. The following is a high-level summary of the steps involved in performing the Jeep Wrangler D clutch repair:

1. Initial Assessment: Verify the presence of DTCs P0733-00, P1DA8-00, or P1D92-00. If confirmed, perform a D clutch circuit pressure check.
2. Transmission Preparation: Remove the torque converter. For 4WD vehicles, remove the transmission housing extension bolts and the extension housing. Remove the transmission output shaft seal and output shaft snap ring (4x4 only). For 2WD vehicles, remove the output shaft flange locknut staking, nut, and flange.
3. Oil Pan and Valve Body Removal: Remove the transmission oil pan bolts and carefully remove the oil pan and gasket. Disconnect the Hydraulic Impulse Oil Storage (H.I.S.) connector (if equipped) and remove its bolts. Remove the valve body assembly end retainer bolts and lift the electrical connector lock to release the internal harness. Remove the valve body assembly, fluid port, fluid transfer tube, and O-rings.
4. Oil Pump Housing Disassembly: Remove the input shaft O-ring and then the oil pump housing bolts. Carefully pry the oil pump housing away from the case.
5. Clutch Pack Disassembly: From the front of the transmission, remove the oil pump housing. Remove the B clutch spring damper. Remove the park pawl lock rod guide plate bolts and the plate. Remove the input/output shaft and P4 annulus drum assembly from the case. Position this assembly on a press fixture. Remove the B clutch pack and the P1 annulus/B clutch hub assembly from the P4 annulus drum.
6. D Clutch Drum Removal: Remove the thrust bearing and holding plate from the P1 planetary carrier. Position the Rings Support on the P4 annulus drum assembly to protect it. Pry the snap ring from the opposite side of its openings to release it, then remove the P1 planetary carrier. Remove the input shaft with P2 planetary carrier, followed by the thrust bearing and washer. Remove the P2 annulus/P3 sun gear and finally, remove the D clutch drum from the P4 annulus drum.
7. D Clutch Reassembly: Install a NEW P4 planetary carrier/output shaft lock ring into the P4 annulus drum and stake its locking tabs. Install the D clutch drum into the P4 annulus drum. Install the P2 annulus/P3 sun gear into the drum assembly. Install the thrust bearing and washer, then the input shaft with P2 planetary carrier into the drum assembly. Install the snap ring in the correct orientation. Install the thrust bearing and holding plate onto the P1 planetary carrier. Install the selectable shim to the P1 annulus/B clutch hub, then install the P1 annulus/B clutch hub assembly onto the P4 annulus drum. Install the B clutch discs and plates, ensuring the transmission is in a vertical position. Install the snap ring.
8. Transmission Reassembly: Install the input/output shaft and P4 annulus drum assembly into the case. Install the park pawl lock rod onto its fork and position the guide plate. Install the clutch B damper spring. Carefully position the oil pump housing assembly into the case and install a new input shaft O-ring. Install NEW transmission oil pump assembly to case bolts. Temporarily install the Manual Park Release (MPR) lever to release tension on the shift fork. Replace the fluid transfer tube O-rings and install the fluid transfer tube. Install valve body alignment pins, then the valve body assembly and its bolts. Install the electrical harness guide sleeve and latch the electrical connector lock. Install the Output Speed Sensor (OSS) and its bolt, ensuring correct pin alignment. Install the H.I.S. (if equipped) and connect its electrical connector. Remove the tie strap and return the manual release lever to its original position. Position the transmission oil pan and gasket, then install the oil pan bolts. Position the new output shaft seal flush with the case. For 4x4 vehicles, position the extension housing and install its bolts. For 2WD vehicles, remove the old seal from the output flange, replace with a new O-ring, and install the output shaft flange, nut, and stake the nut.
9. Final Steps: Install the torque converter. Before installing the transmission into the vehicle, pre-fill it as outlined in the FILL TRANSMISSION AFTER SERVICE procedure. Install the transmission. Finally, use wiTECH to complete the Quick Learn Procedure and clear any remaining DTCs.

Required Tools or Parts

Performing this D clutch repair requires specific parts and special tools:

Spare Parts

• D Clutch Repair Kit (4x4 JL, JT, WD, WK): Part No. 68676890AA
• D Clutch Repair Kit (4x4 WL): Part No. 68676891AA
• D Clutch Repair Kit (4x4 DS, DT, DX, WS): Part No. 68676887AA
• D Clutch Repair Kit (AWD LA, LD, LX): Part No. 68239499AC
• D Clutch Repair Kit (RWD LA, LD, LX): Part No. 68676892AA
• D Clutch Repair Kit (RWD WD, WK): Part No. 68676894AA
• D Clutch Repair Kit (RWD DS, DT, DX, WS): Part No. 68676893AA
• Automatic Transmission Fluid: Part No. 68218925AB (10 units)

Special Tools/Equipment

• Guide Sleeve: Ref. No. 10377
• Press Fixture: Ref. No. 8925-3
• Bearing/Gear: Ref. No. 1130
• Rings, Support: Ref. No. 10378

Owner Action

If you own a 2021-2023 Jeep Wrangler, Ram, Dodge, or Chrysler vehicle equipped with the Eight-Speed Auto 850RE Transmission and experience the Malfunction Indicator Lamp (MIL) illuminating, especially if accompanied by unusual transmission behavior, it is recommended to have your vehicle inspected by a qualified Stellantis service technician. They can diagnose the issue by checking for the specific DTCs (P0733-00, P1DA8-00, P1D92-00) and perform the necessary D clutch repair as outlined in TSB 21-039-24. This repair is reimbursable within the provisions of the warranty.

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Source: NHTSA ID: 11001771