P0733 on 2018-2025 Jeep Wrangler: Gear 3 Incorrect Ratio Causes and Fixes

What's Unique About the 2018-2025 Jeep WRANGLER

The Jeep Wrangler JL (2018-present) uses variants of the ZF 8-speed automatic transmission, such as the 850RE and 8HP75. While generally a robust transmission, this platform has a well-documented weakness in the 'D' clutch assembly. Aftermarket specialists like Sonnax have identified that the thin, stamped original equipment (OE) backing plate for the D-clutch can flex under pressure. This flexing, or 'coning', causes uneven pressure on the clutch plates, leading to concentrated heat, premature wear, and eventual burnup of the clutch material. Stellantis (Jeep's parent company) has issued multiple Technical Service Bulletins (TSBs) acknowledging that this internal clutch failure is the specific cause for P0733, often accompanied by codes P1DA8 and P1D92. This is not a generic fluid or solenoid issue; it's a known mechanical failure point requiring a specific internal repair kit.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: The 2018 model year was an overlap year for the Jeep Wrangler, with both the older JK and new JL generations being sold. This P0733 issue and the associated TSBs specifically apply to the 2018-2025 Jeep Wrangler JL equipped with the 8-speed automatic transmission (e.g., 850RE, 8HP75). It is not a common issue on the JK, which used different transmissions (e.g., 42RLE, W5A580).

Symptoms You May Notice

• Check Engine Light or Malfunction Indicator Lamp (MIL) is on
• Transmission slips, especially when shifting into or driving in 3rd gear
• Harsh, jerky, or delayed shifting, particularly around 3rd gear
• Vehicle enters 'limp mode,' often getting stuck in a lower gear
• Poor acceleration or lack of power
• Vehicle may not move in reverse, sometimes accompanied by a 'Shift to P then Desired Gear' message
• Vehicle will not shift higher than third gear
🎬 See this breakdown of P0733 causes and potential fixes.

Most Likely Causes

1. Internal 'D' Clutch Failure 🔴 High Probability Multiple manufacturer TSBs (S2621000003, 21-009-25 REV. C) confirm this is a known weakness in the 850RE and related 8-speed transmissions. Aftermarket company Sonnax notes that the thin, stamped OE backing plate can flex, causing uneven wear and clutch burnup. This is a widespread issue across many Stellantis products using this transmission family.
   How to confirm: A professional technician will confirm by verifying P0733 and associated codes (like P1DA8, P1D92), checking fluid for fine black clutch material, and referencing the relevant TSBs. Diagnosis is often confirmed with a clutch air pressure test and ultimately upon transmission disassembly.
   Typical fix: Install the manufacturer-specified 'D Clutch Repair Kit' (also called an Output Shaft Kit) as outlined in the TSBs. This is an internal transmission repair, not a full replacement. Many shops recommend also installing an upgraded, thicker billet steel backing plate (like Sonnax 35570-50) to prevent recurrence.
   Est. part cost: $300-$600 for the OEM clutch kit and necessary seals/gaskets.
2. Low or Contaminated Transmission Fluid ⚪ Low Probability While possible, it's a very unlikely root cause on this specific platform given the known TSBs for mechanical failure. However, fluid that is low or heavily contaminated with debris (usually from the failing D-clutch) will cause shifting problems. Clean fluid with a correct level makes internal failure more likely.
   How to confirm: Check the transmission fluid level and condition. The fluid should be at the correct level, have a reddish/brown hue (ZF fluid is not bright red), and not smell burnt or contain excessive metal particles or fine black clutch material. Note: The 850RE does not have a traditional dipstick, requiring a specific lift and temperature procedure to check the fluid level.
   Typical fix: Perform a transmission fluid and filter service. If the fluid is heavily contaminated, it is a symptom of the internal clutch failure mentioned above, and a fluid change alone will not fix the problem.
   Est. part cost: $150-$300 for fluid and a filter kit.
3. Faulty Valve Body or Shift Solenoid ⚪ Low Probability A failing solenoid or a stuck valve within the valve body can cause pressure issues leading to incorrect gear ratios. However, this is far less common for this specific code on the Wrangler JL compared to the documented D-clutch failure. A valve body issue would be a secondary diagnosis if the D-clutch passes an air pressure test, which is unlikely.
   How to confirm: A professional scan tool can be used to command solenoids on and off and monitor pressure readings to identify a malfunction. This is typically performed after ruling out fluid issues but before transmission removal.
   Typical fix: Replace the faulty shift solenoid or the entire valve body assembly.
   Est. part cost: $300-$1200 for a valve body or solenoid pack.

Diagnosis Steps

1. Verify the code P0733 and check for any other related transmission codes (like P1DA8, P1D92) using an OBD-II scanner.
2. Check the manufacturer TSBs for the vehicle's year and model. For the Wrangler JL, TSB 21-009-25 REV. C points directly to a D-clutch issue for vehicles with over 7,000 miles.
3. Check the transmission fluid level and condition. Dark, burnt, or fluid containing fine black clutch material is a strong indicator of internal mechanical failure.
4. If TSBs point to clutch failure, a technician will perform a clutch air pressure test to confirm a leak in the D-clutch hydraulic circuit before disassembly.
5. Confirm the diagnosis requires the internal D-clutch repair as specified by the manufacturer. Do not approve a full transmission replacement unless there is evidence of widespread damage beyond the D-clutch.
6. Perform a transmission adaptation (quick learn) procedure with a scan tool after the repair is complete.

Parts You'll Likely Need

• D Clutch Repair Kit (Output Shaft Kit) (OEM #68676890AB (For JL/JT 4x4)) — This is the specific fix identified by Jeep/Stellantis in TSB 21-009-25 Rev. C for code P0733 on the 8-speed automatic transmission.
  Trusted brands: Mopar (OEM)
  OEM price range: $300-$550
• Heavy Duty 'D' Clutch Backing Plate (OEM #35570-50 (Sonnax Part Number)) — The OE backing plate is prone to flexing, which causes the clutch failure. This thicker, billet steel plate prevents flexing and is a highly recommended durability upgrade during the repair.
  Trusted brands: Sonnax
  Aftermarket price range: $60-$90
• Automatic Transmission Fluid (ZF 8&9 Speed ATF or equivalent) (OEM #68218925AB) — New fluid is required when performing any internal transmission service. A full fluid exchange will require approximately 8-10 liters.
  Trusted brands: Mopar, Liqui Moly (Top Tec 1800), Pentosin
  OEM price range: $25-$40 per liter
  Aftermarket price range: $15-$30 per liter
• Transmission Pan with Integrated Filter (OEM #68225344AA) — The filter is integrated into the pan on this transmission and should be replaced during the service to remove contaminants from the old fluid and failed clutch.
  Trusted brands: Mopar (OEM), ZF
  OEM price range: $150-$250
  Aftermarket price range: $100-$200

Related Codes That Often Appear With This One

• P1DA8-00 — Incorrect Gear Ratio Clutch A, B, or D Defective. This code is frequently cited alongside P0733 in Jeep TSBs related to the D-clutch failure.
• P1D92-00 — Incorrect Gear Ratio - Clutch 4 Defective. This is another code specifically mentioned in the TSBs for the same D-clutch issue.

Technical Service Bulletins (TSBs) & Recalls

• 21-009-25 REV. C: The primary TSB outlining the P0733, P1DA8, and P1D92 codes, symptoms (including loss of reverse), and the D-clutch replacement procedure for a wide range of Stellantis vehicles.
• S2621000003 REV.A: Lists P0733 for 2025 models with various 8-speed transmissions.
• 9100390 Rev 1 & 9100534: Star Online publications advising dealers that a repair kit is available and transmission replacement is NOT required for P0733.

Platform-Specific Known Issues

• A series of Technical Service Bulletins (TSBs) have been released by Stellantis for the 850RE and related 8-speed transmissions concerning P0733. TSB 21-009-25 Rev. C specifically notes the code P0733-00 (Gear 3 Shift Incorrect Ratio) on vehicles with over 7,000 miles.
• TS

Mechanic-Grade Diagnostic Values

• 'D' Clutch Circuit Air Pressure Test — expected: The clutch pack should hold pressure with no audible leaks or rapid pressure drop.. Failure: A noticeable hiss or inability to hold pressure indicates a leak in the clutch circuit seals or piston, confirming the internal failure.
• Clutch Pack Air Test Pressure — expected: Low pressure, between 20-50 PSI.. Failure: Applying excessive pressure during an air test can damage otherwise good seals.

Scan Tool Commands That Help

• wiTECH (Dealer Tool), Jscan, Foxwell, etc.: Reset TCM Adaptations / Quick Learn — This function must be performed after the D-clutch repair is complete. It erases the old shift adaptations that the TCM learned while compensating for the slipping clutch and allows it to relearn new, correct shift points with the repaired hardware. Failure to perform this step can result in continued poor shifting even after the mechanical fix.
• wiTECH (Dealer Tool): Clutch Air Pressure Tests — The dealer service library contains a guided procedure for performing air pressure tests on specific clutch circuits. For P0733, the technician follows the procedure for the 'D' clutch to confirm a hydraulic leak, which is the definitive diagnostic step before authorizing an internal repair.

Wiring & Ground Locations

• G901C — Located on the transmission itself, part of the transmission harness family.. A poor ground at this location could potentially cause erratic behavior from sensors or solenoids on the transmission, although it is an unlikely root cause for the specific P0733 D-clutch failure pattern. Verifying this ground is clean and tight is a basic electrical due diligence step.
• TCM Connector — The Transmission Control Module (TCM) is integrated with the valve body inside the transmission pan (it is a mechatronic unit). The main harness connector is on the exterior of the transmission case.. All sensor data and solenoid commands pass through this main connector. While not a common failure point, any fluid intrusion or pin corrosion here could cause a wide range of transmission faults, including ratio errors.
• G904A / G904B — Located on the dashboard harness, likely in the driver-side footwell area.. The dash harness contains wiring that communicates between the Powertrain Control Module (PCM), Body Control Module (BCM), and the instrument cluster. A poor ground here is more likely to cause communication or display issues than a specific gear ratio code, but it's part of the overall electrical system integrity.

Real Owner Repair Stories

• JLWranglerForums.com user JeffBTV (2020 Jeep Wrangler JL Automatic) — Shifting problems, specifically running into 3rd gear. Check engine light appeared with code P0733 (3rd gear ratio problem).
  ❌ Tried (didn't work) The dealer initially considered a full transmission replacement, but this was denied by corporate (Stellantis/FCA).
  ✅ What actually fixed it The dealer was instructed by corporate to perform a repair, not a replacement. They installed a 'clutch rebuild kit' or 'new shaft kit' which corresponds to the D-clutch repair outlined in TSBs. The user noted that the parts were scarce, indicating a common failure. The repair resolved the issue.
• JLWranglerForums.com user (2021 JLUR with 23,000 miles) — Reverse clunk, hard upshift from 3rd to 4th gear, then reverse wouldn't engage with a 'shift to park then desired gear' message.
  ❌ Tried (didn't work) Initially, the dealer only found code P1DA8-00 and checked fluid for metal (none found).
  ✅ What actually fixed it The dealer followed TSB 21-009-25 Rev A, which is the D-clutch repair. They removed the transmission, disassembled it, replaced the D-clutch assembly, and performed a quick learn and adaptation. This confirms the fix for the related code P1DA8 also involves the same D-clutch replacement as P0733.

OEM Part Supersession History

• 68676890AA → 68676890AB — The supersession from AA to AB likely indicates a revision or update to the components within the D-clutch repair kit. Manufacturers often update parts to improve durability or address the root cause of the original failure. Using the latest part number is critical to ensure the most robust repair.
  Heads up: The older part number should be avoided. Always use the latest revision (AB or newer) to ensure the updated components are installed.

Model Year Variations Within This Range

• 2018-present: The ZF 8-speed family used in the Wrangler includes Gen 1 (e.g., 8HP70) and Gen 2 (e.g., 850RE/8HP75) versions. The 850RE is a Chrysler-built version of the 8HP50. While the D-clutch issue is prevalent across these, there can be internal differences in gear ratios and control systems between model years and engine pairings (3.6L V6, 2.0T, EcoDiesel). However, the TSB for the D-clutch failure applies broadly to the 850RE/8HP75 transmissions in this year range.