2021-2023 Stellantis Transmission D Clutch Repair TSB 21-039-24

Stellantis has issued Technical Service Bulletin (TSB) 21-039-24 REV. C to address specific transmission issues in various 2021-2023 models equipped with the Eight-Speed Auto 850RE Transmission (Sales Code DFT). This bulletin, dated September 6, 2024, supersedes TSB 21-039-24 REV. B and provides updated repair procedures and labor times for a D clutch repair.

This TSB is relevant for owners of a 2021 Jeep Wrangler manufacturer_communication who may be experiencing transmission problems. The primary concern is a malfunction of the D clutch within the transmission, leading to warning lights and specific diagnostic trouble codes.

Symptoms

Owners of affected vehicles will typically notice a Malfunction Indicator Lamp (MIL) illumination on the dashboard. This warning light is accompanied by the vehicle setting one or more specific Diagnostic Trouble Codes (DTCs) related to incorrect gear ratios or a defective D clutch.

Fault Codes / DTCs

If your vehicle exhibits the symptoms described, a diagnostic scan will likely reveal one or more of the following DTCs:

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

For a proper diagnosis, technicians are instructed to confirm the presence of a Malfunction Indicator Lamp (MIL) and one or more of the listed DTCs (P0733-00, P1DA8-00, or P1D92-00). If these conditions are met, the next step involves performing a pressure check on the D clutch circuit using the dealer connect procedure. Detailed service procedures for this check are available in DealerCONNECT/Service Library under 'Service Info > 21 - Transmission and Transfer Case / Automatic - 8HP50/850RE / Diagnosis and Testing / Clutch Air Pressure Tests'. If the D clutch fails this pressure check, the repair procedure outlined in the TSB must be followed.

Important Warnings

Several critical warnings are highlighted in this TSB to ensure proper repair and prevent further damage:

• Transmission Control Module (TCM) / Transmission Control Module Assembly (TCMA) Sensitivity: The TCM or TCMA is highly sensitive to Electrostatic Discharge (ESD). Technicians must always use a ground strap and adhere to ESD guidelines for sensitive devices. Failure to do so can result in 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. For specifics, refer to the FLUIDS, LUBRICANTS AND GENUINE PARTS information.
• TCM Adaptation Procedure: If the transmission is reconditioned (e.g., clutch or seal replacement) or replaced, it is mandatory to perform the TCM Adaptation Procedure. Refer to the detailed service procedures in DealerCONNECT/Service Library under 'Service Info > 08 - Electrical / 8E - Electronic Control Modules / Module, Transmission Control / Module Programming'.

Repair Procedure Summary

The repair detailed in TSB 21-039-24 REV. C involves replacing the D clutch within the Eight-Speed Auto 850RE Transmission. The procedure is extensive and requires specialized tools and careful attention to detail. It begins with the removal of the transmission from the vehicle, followed by a series of disassembly steps to access the D clutch.

Transmission Removal and Initial Disassembly:

1. The transmission is removed from the vehicle. This involves removing the torque converter (Fig. 1).
2. If equipped with 4WD, the transmission housing extension bolts and extension housing are removed (Fig. 2).
3. The transmission output shaft seal (Fig. 3) and output shaft snap ring (for 4x4 only, Fig. 4) are removed.
4. For 2WD vehicles, the output shaft flange locknut staking (Fig. 5) is removed, followed by the flange nut and flange itself. The flange sealing surface is inspected for damage.
5. The transmission oil pan bolts (Fig. 6) are removed, and the oil pan and gasket are carefully detached. The gasket is inspected for reuse.

Accessing Internal Components:

1. If equipped, the Hydraulic Impulse Oil Storage (H.I.S) connector (Fig. 7) is disconnected, and the H.I.S. accumulator and its bolts are removed.
2. The valve body assembly end retainer bolts (Fig. 8) are removed, and the electrical connector lock is lifted to release the internal harness.
3. The Output Speed Sensor (OSS) bolt is removed, and the sensor is gently lifted out (Fig. 9).
4. Using Guide Sleeve 10377, the electrical harness insulator is pulled straight out from the transmission case (Fig. 10).
5. The valve body assembly bolts are removed in a specific order (Fig. 11), and the valve body is then removed.
6. The fluid port (Fig. 12) and fluid transfer tube with O-rings are removed.

D Clutch Disassembly:

1. The input shaft O-ring (Fig. 13) is removed, followed by the oil pump housing bolts (Fig. 14). The input shaft O-ring must be removed before the oil pump.
2. The oil pump housing is carefully pried away from the case (Fig. 15) and then removed from the front of the transmission.
3. The B clutch spring damper (Fig. 16) is removed.
4. The park pawl lock rod guide plate bolts and plate are removed (Fig. 17). A critical note states the transmission must be in a vertical position before the main stack is removed to prevent damage.
5. The input/output shaft and P4 annulus drum assembly (Fig. 18) are removed from the case.
6. The input/output shaft and P4 annulus drum assembly are positioned on a press fixture (Fig. 19).
7. The B clutch pack is removed, followed by the P1 annulus/B clutch hub assembly from the P4 annulus drum (Fig. 20).
8. The thrust bearing and holding plate are removed from the P1 planetary carrier. Three pieces of Rings Support (Fig. 21) are used to prevent damage during removal.
9. The Rings Support is positioned on the P4 annulus drum assembly (Fig. 22). The snap ring is pried from the opposite side of its openings to release it. The P1 planetary carrier is then removed.
10. The input shaft with P2 planetary carrier (Fig. 23) is removed from the drum assembly.
11. The thrust bearing and washer are removed.
12. The P2 annulus/P3 sun gear (Fig. 24) is removed from the drum assembly.
13. The D clutch drum is removed from the P4 annulus drum. Again, three pieces are used to prevent prying damage.
14. For heavy-duty park systems only, the P4 planetary carrier/output shaft lock ring (Fig. 25) is removed, and a new lock ring is installed during reassembly.

Reassembly and Final Steps:

1. A NEW P4 planetary carrier/output shaft assembly is installed into the P4 annulus drum. A new P4 planetary carrier/output shaft lock ring is installed and staked (Fig. 26).
2. The D clutch drum is installed into the P4 annulus drum (Fig. 27).
3. The P2 annulus/P3 sun gear (Fig. 28) and the input shaft with P2 planetary carrier (Fig. 29) are reinstalled.
4. The snap ring is installed in the correct orientation (Fig. 30).
5. The thrust bearing, holding plate, selectable shim, and P1 annulus/B clutch hub assembly (Fig. 31) are reinstalled.
6. The Clutch B discs and plates, including friction plates, wave springs, steel plates, cover plate, and snap ring (Fig. 32, Fig. 33), are installed. The transmission must be vertical during main stack installation.
7. The input/output shaft and P4 annulus drum assembly are installed into the case (Fig. 34).
8. The park pawl lock rod is installed onto the fork (Fig. 35), and the guide plate with its retaining bolts is positioned and installed.
9. The clutch B damper spring is installed (Fig. 36).
10. The oil pump housing assembly is carefully positioned into the case, and a new input shaft O-ring is installed (Fig. 37). The oil pump must be firmly pressed into place before tightening with bolts.
11. A NEW transmission oil pump assembly is installed with its bolts (Fig. 38).
12. The Manual Park Release (MPR) lever is temporarily installed in a reversed position to release tension on the shift fork, secured with a tie strap (Fig. 39), to ease valve body assembly installation.
13. The fluid transfer tube O-rings are replaced, and the fluid transfer tube is installed (Fig. 40).
14. Valve body alignment pins are used as guides, ensuring the shift fork lines up properly. The valve body assembly is positioned, and its bolts are installed (Fig. 41). Guide pins are removed after several bolts are hand-tightened.
15. Using Guide Sleeve 10377, the electrical harness guide sleeve is installed (Fig. 42). The electrical connector lock is latched (Fig. 43), and the valve body end bolt and electrical connector lock bolt are installed.
16. The Output Speed Sensor (OSS) is installed, taking care to correctly position its guide pin (Fig. 44, Fig. 45) before tightening its bolt (Fig. 46).
17. If equipped, the H.I.S. and its bolts are installed (Fig. 47), and the H.I.S. electrical connector is connected.
18. The tie strap is removed, and the manual release lever is returned to its original position (Fig. 48), with the lever nut installed.
19. The transmission oil pan and gasket are positioned (Fig. 49), and the oil pan bolts are installed. For 4x4 only, the seal must be installed flush with the case.
20. A new output shaft seal is positioned (Fig. 50) and installed using a Seal Installer (Fig. 51).
21. For 4x4 vehicles, the extension housing is positioned and its bolts installed (Fig. 52).
22. For 2WD vehicles, the old seal from the output flange is removed and replaced with a new output flange O-ring (Fig. 53). The output shaft flange (Fig. 54) is installed, followed by a new output shaft flange nut and washer, which is then staked.
23. The torque converter is installed (Fig. 55).
24. For WL 4x4 only, a green O-ring is installed on the output shaft (Fig. 56).
25. Before installing the transmission in the vehicle, it is pre-filled as outlined in the 'Fill Transmission After Service' procedure. The transmission is then installed.
26. Finally, wiTECH is used to complete the Quick Learn Procedure and clear any DTCs.

Required Tools or Parts

This repair requires specific D Clutch Repair Kits depending on the vehicle's drive type and model, as well as specialized tools.

D Clutch Repair Kits:

Qty	Part No.	Description	Notes
1	68676890AB	D Clutch Repair Kit (4x4)	JL, JT, WD, WK
1	68676891AB	D Clutch Repair Kit (4x4)	WL
1	68676887AB	D Clutch Repair Kit (4x4)	DS, DT, DX, WS
1	68239499AD	D Clutch Repair Kit (AWD)	LA, LD, LX
1	68676892AB	D Clutch Repair Kit (RWD)	LA, LD, LX
1	68676894AB	D Clutch Repair Kit (RWD)	WD, WK
1	68676893AB	D Clutch Repair Kit (RWD)	DS, DT, DX, WS
10	68218925AB	Automatic Transmission Fluid

Special Tools/Equipment:

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

Owner Action

If your 2021-2023 Stellantis vehicle, including the 2021 Jeep Wrangler manufacturer_communication, is displaying a Malfunction Indicator Lamp (MIL) and you suspect a transmission issue, particularly with the Eight-Speed Auto 850RE Transmission, it is crucial to have it diagnosed by a qualified technician. The presence of DTCs P0733-00, P1DA8-00, or P1D92-00 strongly indicates the need for a D clutch repair.

This repair is reimbursable within the provisions of your vehicle's warranty. Contact your authorized Stellantis dealership to schedule a diagnostic appointment and discuss the necessary repairs under TSB 21-039-24 REV. C.

NHTSA ID: 11007649