8-Speed Automatic Transmission Assembly for 2020-2023 Ram 1500

A quick look at your own vehicle makes sure the right transmission shows up:

• Verify the 8th digit of the VIN is 'H' (3.0L EcoDiesel V6 engine).
• Verify the truck is a 4x4 (4WD) model with front CV shafts and a transfer case.
• Verify the truck has 6-lug wheels (5th Gen 'New Style' DT body).
• Verify the OEM part number on the transmission case tag matches 68269521AB or 68269521AC.

What the install really takes — plan and budget with confidence:

Special tools this job needs:

• Transmission jack
• Low-range inch-pound torque wrench
• OBD-II scan tool with real-time TFT reading and Quick Learn capability (wiTECH or AlfaOBD)
• Fluid fill pump adapter for ZF 8-speed fill ports

Budget for these consumables at install:

• ZF Lifeguard Fluid 8 or Mopar 8&9 Speed ATF (Part #68218925AB)
• Replacement transmission oil pan assembly with integrated filter, magnets, and gasket (Mopar Part #68362041AC)
• Front pump / input shaft torque converter seal
• Professional hot flush transmission cooler-line agent

What your vehicle’s computers will need after the swap:

What’s involved: TCM Adaptive Relearn (Quick Learn / Static Adaptation)

A Mopar-specific scan tool (wiTECH) or capable professional diagnostic system (AlfaOBD) is required to perform the 'Quick Learn' calibration sequence and reset adaptive values. Skipping this step can cause immediate clutch damage and extremely harsh shifts.

Pro tips for a smooth first start-up — hand them to whoever does the install:

• Exhaust Crossover Clearance: On 4x4 models, the exhaust crossover pipe runs directly beneath the transmission oil pan. The transmission must be unbolted from the crossmember and lifted 1.5 to 2 inches to remove/install the pan without damage.
• Torque Converter Seating: The torque converter must be fully seated (typically three distinct clicks/drops) before bolting the bellhousing to the engine. Forcing it will permanently crack the internal oil pump.
• Precise Fluid Leveling: Leveling must be done with the vehicle perfectly level, engine running, and fluid temperature strictly between 86°F and 122°F (30°C to 50°C). Exceeding this temperature results in under-filling.
• Pan Bolt Torque Sequence: The 13 plastic pan bolts must be torqued in a specific crossing sequence to exactly 96 in-lbs (8 ft-lbs) to prevent warping or snapping.
• Dowel Pins: Ensure alignment dowel pins between the engine block and transmission bellhousing are present and clean to prevent stress fractures.

Easy to get right once you know them:

• Using incorrect fluid (such as standard ATF+4 or generic multi-vehicle fluids) instead of ZF Lifeguard 8 or Mopar 8&9 Speed ATF.
• Failing to level the vehicle during fluid checks, leading to severe under-fill due to the truck's natural rear-end rake.
• Reusing the old pan/filter, which runs new fluid through a dirty, clogged integrated filter.
• Skipping the adaptive 'Quick Learn' relearn procedure, resulting in harsh shifts that damage clutch packs.
• Skipping the transmission cooler line flush, allowing debris from the failed unit to contaminate the replacement transmission.
• Misdiagnosing an engine-related issue (like the EcoDiesel HPFP failure or crankshaft position sensor tone wheel) as a transmission failure.

Not issues with the units on this page — the manufacturer documented these for every transmission of this family, wherever you buy one. Handy for your installer: