8-Speed Automatic Transmission Assembly for 2018-2024 Ram 1500, Classic

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

• Verify VIN's 8th digit is a 5.7L Hemi V8 engine.
• Confirm vehicle is a 4x4 (4WD) model with a front driveshaft and transfer case.
• Confirm vehicle has a 5-lug wheel pattern (Classic DS body style).
• Confirm vehicle uses a dashboard rotary dial shifter.
• Confirm vehicle does not have the 48-volt eTorque mild-hybrid system.
• Confirm transmission option code is DFD (8HP70).

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

Special tools this job needs:

• Heavy-duty transmission jack
• Fluid transfer pump/injector
• OBD-II scan tool with live data (wiTECH, AlfaOBD, or Autel)
• Jack stands or lift capable of raising rear axle 8 to 10 inches
• 10mm hex bit for the fill plug
• Torque wrench

Budget for these consumables at install:

• ZF LifeguardFluid 8 or Mopar 8 & 9 Speed ATF (P/N 68218925AB)
• New integrated plastic oil pan assembly (includes filter, gasket, and new pan bolts)
• Front torque converter seal (pump input shaft seal)
• Rear output shaft seal (where transfer case mounts)
• Professional-grade transmission cooler line flush

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

What’s involved: TCM Adaptive Relearn (Quicklearn) and VIN-Specific Programming

The TCM is integrated into the mechatronic valve body. Option A (Preferred): Swap your original TCM onto the replacement transmission's valve body for plug-and-play operation. Option B: Keep the donor TCM, write your truck's VIN to the module, and perform a 'Quicklearn' adaptive reset using AlfaOBD, Autel, or dealer wiTECH.

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

• Torque Converter Seating: Ensure the torque converter is fully seated into the front pump before bolting to the engine. Forcing it will crack the pump.
• The 8-to-10 Inch Rear Lift Rule: The transmission has no dipstick and must be filled level. Raise the rear axle 8-10 inches to level the pan rail.
• Strict Temperature Fill Window: Final fluid level check must be done with engine running and fluid temperature strictly between 30C (86F) and 50C (122F).
• Thermal Bypass Contamination: Replace the thermal bypass valve or install a bypass delete kit to prevent old metal shavings from ruining the new unit.
• Accessing Torque Converter Bolts: Access these bolts by removing the starter motor. Do not use an impact wrench on these sensitive bolts.

Easy to get right once you know them:

• Using the wrong fluid (such as ATF+4 or generic multi-vehicle fluids) instead of ZF Lifeguard 8 / Mopar 8 & 9 Speed ATF.
• Underfilling the transmission due to checking fluid with the engine off or when the transmission is too hot.
• Failing to flush the cooler lines, which introduces debris from the failed unit into the replacement transmission.
• Forcing the bellhousing bolts to draw the transmission tight when the torque converter is not fully seated, cracking the front pump.
• Skipping the electronic adaptive relearn procedure, leading to poor or erratic shifting.

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: