2021-2025 Stellantis 850RE Transmission D Clutch Repair

Owners of various 2021-2025 Stellantis vehicles equipped with the Eight-Speed Auto 850RE Transmission (Sales Code DFT) may experience a Malfunction Indicator Lamp (MIL) illumination alongside specific transmission performance issues. This is addressed by Technical Service Bulletin (TSB) 21-009-25, which details a repair procedure for the D clutch.

This bulletin, issued on January 14, 2025, supersedes TSB 21-039-24 REV. H, dated December 13, 2024. The updated TSB includes revisions such as an expanded list of affected model years, additional customer symptoms, and updated claims data.

Symptoms

Customers may observe a Malfunction Indicator Lamp (MIL) illumination on their dashboard. In addition to the warning light, the vehicle may exhibit one or more of the following operational issues related to the Stellantis 850RE D clutch:

• "Transmission slips when shifting."
• "Vehicle will not move in reverse."
• "Vehicle will not shift higher than third gear."

Fault Codes / DTCs

These symptoms are typically accompanied by specific Diagnostic Trouble Codes (DTCs) stored in the vehicle's system. The presence of these codes indicates a problem with the transmission's D clutch:

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

Diagnosis and Trigger Conditions

Diagnosis for this issue begins if a customer reports the described symptoms and a Malfunction Indicator Lamp (MIL) is illuminated. Technicians will then check for the presence of the specific DTCs: P0733-00, P1DA8-00, or P1D92-00. If these codes are present, the TSB directs the technician to proceed with the D clutch repair procedure. If no DTCs are found, the bulletin does not apply.

Important Warnings for Owners and Technicians

Several critical warnings are highlighted in TSB 21-009-25 to ensure proper repair and prevent further damage:

• Electrostatic Discharge (ESD) Sensitivity: The Transmission Control Module (TCM) or Transmission Control Module Assembly (TCMA) is highly sensitive to ESD. Technicians must use a ground strap and follow ESD guidelines to prevent damage to these components.
• TCM Adaptation Procedure: If the transmission is reconditioned (clutch/seal replacement) or replaced, a TCM Adaptation Procedure is mandatory. This procedure is detailed in DealerCONNECT/Service Library.
• Normal Transmission Debris: "It is normal for the transmission to have fine debris present in the oil pan and stuck to the magnets. Burnt oil and debris do not warrant a transmission replacement for D piston seal failure." This prevents unnecessary transmission replacements.
• Transmission Positioning: When installing the main stack during reassembly, the transmission must be in a vertical position to prevent damage to the drums.
• Lock Ring Replacement: Technicians must "Discard the lock ring and install a NEW lock ring during assembly" for the P4 planetary carrier/output shaft.
• Unique Transmission Fluid: "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." Always refer to FLUIDS, LUBRICANTS AND GENUINE PARTS for specifics on the correct fluid.
• Seal Installation: Any new seals, such as the output shaft seal, must be installed flush with the case. Driving the seal deeper can cause damage and lead to leaks.
• Nut Staking: The output shaft flange nut must be staked to prevent loosening due to vibration.

Repair Procedure Summary

The repair outlined in TSB 21-009-25 involves the replacement of the D clutch within the Eight-Speed Auto 850RE Transmission. The process is extensive and requires careful disassembly and reassembly of the transmission components. Here is a high-level overview of the steps:

1. Preparation: Verify the presence of specific DTCs (P0733-00, P1DA8-00, P1D92-00) before proceeding.
2. Disassembly - External Components: Remove the torque converter. For 4WD vehicles, remove the transmission housing extension. Remove the output shaft snap ring (4x4) or output shaft flange locknut staking (2WD) and the output shaft flange.
3. Disassembly - Internal Components: Drain the transmission fluid and remove the transmission oil pan. Disconnect the Hydraulic Impulse Oil Storage (H.I.S) if equipped. Remove valve body assembly bolts, release the electrical connector lock, and carefully remove the Output Speed Sensor (OSS).
4. Valve Body and Oil Pump Removal: Use a Guide Sleeve (10377) to pull the electrical harness insulator. Remove the valve body assembly and its associated bolts. Remove the fluid port, fluid transfer tube, and input shaft O-ring. Discard the old oil pump housing bolts, then pry and remove the oil pump housing.
5. Clutch Pack Access: Remove the B clutch spring damper and the park pawl lock rod guide plate. Remove the input/output shaft and P4 annulus drum assembly. This assembly is then placed on a press fixture (8925-3) to facilitate the removal of the B clutch pack.
6. D Clutch Removal: Remove the P1 annulus/B clutch hub assembly, thrust bearing, and holding plate. Position Rings, Support (10378) on the P4 annulus drum to protect it, then pry and remove the snap ring. Remove the P1 planetary carrier and the input shaft with P2 planetary carrier, along with its thrust bearing and washer. Finally, remove the P2 annulus/P3 sun gear and the D clutch drum itself.
7. New Part Installation and Reassembly: Install a NEW P4 planetary carrier/output shaft assembly and a NEW lock ring, ensuring it is properly staked. The D clutch drum is then installed, followed by the P2 annulus/P3 sun gear, input shaft, and snap ring. The B clutch discs and plates are installed.
8. Final Reassembly: The input/output shaft and P4 annulus drum assembly are installed back into the transmission case, ensuring the transmission is vertical. The park pawl lock rod and B clutch damper spring are reinstalled. The oil pump housing, NEW input shaft O-ring, and NEW oil pump cover retaining bolts are installed with specific torque and tightening sequences.
9. External Component Reinstallation: Install NEW fluid transfer tube O-rings and the fluid transfer tube. Reinstall the valve body assembly, OSS, and HIS (if equipped). The transmission oil pan and gasket are reinstalled with new bolts. The output shaft seal is installed using Installer, Seal (9677), followed by the extension housing (4x4) and torque converter.
10. Post-Repair Procedures: Pre-fill the transmission with the correct unique fluid. Install the transmission back into the vehicle. Finally, use wiTECH to perform a Quick Learn Procedure and clear any stored DTCs. This ensures the Stellantis 850RE D clutch functions correctly after the repair.

Required Tools or Parts

To perform this repair, specific parts and special tools are required:

Special Tools

• Guide Sleeve: 10377
• Press Fixture: 8925-3
• Bearing/Gear: 1130
• Rings, Support: 10378
• Installer, Seal: 9677

Replacement Parts (Examples)

• D Clutch Repair Kit (4x4 JL, JT, WD, WK): Part No. 68676890AB
• D Clutch Repair Kit (4x4 WL): Part No. 68676891AB
• D Clutch Repair Kit (4x4 DS, DT, DX, WS): Part No. 68676887AB
• D Clutch Repair Kit (AWD LA, LD, LX): Part No. 68239499AD
• D Clutch Repair Kit (RWD LA, LD, LX): Part No. 68676892AB
• D Clutch Repair Kit (RWD WD, WK, WL): Part No. 68676894AB
• D Clutch Repair Kit (RWD DS, DT, DX, WS): Part No. 68676893AB
• Automatic Transmission Fluid: Part No. 68218925AB (Note: This is a unique fluid, not compatible with ATF+4).

Owner Action

If you are experiencing any of the symptoms described, such as a lit Malfunction Indicator Lamp (MIL), transmission slipping, difficulty shifting, or the vehicle not moving in reverse, and your vehicle is one of the affected 2021-2025 Stellantis models with the Eight-Speed Auto 850RE Transmission, it is recommended to contact your authorized Stellantis dealer. Provide them with the symptoms you are observing and mention Technical Service Bulletin 21-009-25. This repair is reimbursable within the provisions of the warranty.

NHTSA ID: 11013016