8-Speed Automatic Transmission Assembly for 2018-2025 Dodge Durango

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

• Verify the vehicle is Rear-Wheel Drive (4x2) and not All-Wheel Drive (AWD).
• Confirm the engine is the 5.7L V8 Hemi.
• Check the vehicle build sheet or glovebox for axle ratio option code DFD (3.09 rear axle ratio).

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

Special tools this job needs:

• Transmission jack
• Fluid fill pump
• OBD2 scanner with bi-directional support (like Mopar wiTECH)
• Torx and Hex bit sets
• Engine support bar
• Extensive socket/wrench set with swivels
• Torque wrench

Budget for these consumables at install:

• Mopar 8 & 9 Speed ATF (Mopar Part # 68218925AB) or ZF Lifeguard Fluid 8
• Mopar Transmission Pan Kit (Mopar Part # 68225344AA or equivalent) with integrated filter, gasket, pan bolts, and drain plug
• Front pump/torque converter input shaft seal
• Transmission cooler-line flush solvent

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

What’s involved: VIN-specific programming and TCM adaptive relearn

The integrated TCM stores the donor vehicle's VIN and security keys. It will trigger an immobilizer/security lock if installed without programming. A dealer-level scan tool (such as Mopar wiTECH) or specialized locksmith tool is required to program the VIN and perform a Quick Learn calibration.

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

• Torque Converter Seating: Must feel three distinct clicks/drops when rotating and pushing the converter in. If not fully seated, bolting the transmission to the engine will crack the oil pump, destroying the unit.
• Fluid Fill Procedure & Temperature: No dipstick. Fluid level must be checked and filled from the side fill plug with the engine running and fluid temperature strictly between 30°C and 50°C (86°F to 122°F).
• Torque Converter Bolt Access: Extremely difficult; requires removing the starter, which may require removing the driver's side exhaust manifold and loosening the engine mount.
• Cooler Line Flush: Must perform a complete flush to prevent old debris from contaminating the new unit and voiding the warranty.
• Dowel Pin Alignment: Ensure engine-to-transmission alignment dowel pins are in place to prevent input shaft misalignment.
• Pan Bolt Tightening Sequence: Plastic pan is sensitive to warping. Bolts must be tightened in a specific crisscross pattern to 10 Nm / 89 in-lbs.

Easy to get right once you know them:

• Using the wrong fluid (using ATF+4 or universal fluids instead of ZF Lifeguard 8 or Mopar 8/9-speed fluid).
• Skipping the programming/relearn, leading to a no-start condition or immediate 6th-gear limp mode.
• Stripping or over-tightening the plastic pan bolts, or reusing old torque-to-yield bolts.
• Incorrect fluid level check (checking with the engine off, which causes severe underfilling).
• Skipping the cooler line flush, leading to immediate contamination and failure.
• Improper torque converter installation (forcing the transmission to seat when the converter is not fully pushed in).

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: