8-Speed Automatic Transmission Assembly for 2018-2019 Dodge Durango

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

• Confirm Your Drivetrain: Ensure your Durango is All-Wheel Drive (AWD) / 4x4. This transmission features a 4WD tailhousing designed to bolt directly to a transfer case and will not fit a Rear-Wheel Drive (RWD / 4x2) model.
• Confirm Your Engine: Verify that your vehicle has the 5.7L Hemi V8 engine (the 8th digit of your VIN must be 'T'). This transmission has a V8-specific bellhousing bolt pattern and will not bolt to the 3.6L V6 or 6.4L V8 engines.
• Verify the Transmission Option Code: Check your vehicle's build sheet or glovebox option codes to confirm you have option code DFK or DFD (both represent the ZF 8HP70).

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

Special tools this job needs:

• Heavy-duty transmission jack
• Long socket extensions
• Swivel/ball-end 3/16" (or 5mm) hex wrench
• OBD2 scan tool capable of reading real-time transmission fluid temperature and initiating a TCM adaptive relearn (such as wiTECH or AlfaOBD)

Budget for these consumables at install:

• ZF Lifeguard 8 (or Mopar 8 & 9 Speed ATF, part number 68218925AA / 68218925AB). Do NOT use ATF+4.
• Approximately 9 to 10 quarts of fluid (dry fill requires 9.0 to 9.5 quarts; service fill requires 5.5 to 6.0 quarts).
• New plastic transmission oil pan assembly (includes integrated filter, gasket, and drain plug).
• Front pump/torque converter seal.
• Rear output shaft seal.
• Professional-grade transmission cooler-line flushing agent.

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

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

The Transmission Control Module (TCM) is physically integrated into the internal valve body (Mechatronics unit) and stores the VIN and configuration of the donor vehicle. You must use a dealer-level scan tool (such as Chrysler's wiTECH system) or a high-end professional diagnostic tool to write your vehicle's VIN to the replacement TCM and perform an Adaptation Drive Learn / Quick Learn procedure. Sources differ on whether the TCM is physically included with this assembly — confirm with us before install.

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

• Torque Converter Seating (Critical): You must ensure the torque converter is fully seated onto the transmission input shaft and pump gears before bolting the transmission to the engine. You should feel/hear three distinct 'clicks' or drops as you rotate and push the converter inward. If it is not fully seated and you force the bellhousing bolts tight, you will crack the internal oil pump, instantly destroying the transmission.
• Perfect Leveling for Fluid Fill: The ZF 8HP70 has no dipstick. To check the fluid level, the vehicle must be raised on a lift or jack stands so that the transmission pan rail is perfectly level.
• Strict Temperature Window for Filling: The final fluid level check must be performed through the fill plug on the side of the case while the engine is idling, the transmission is in Park, and the fluid temperature is strictly between 30°C and 50°C (86°F to 122°F).
• Thermal Bypass Valve Purge: The Dodge Durango utilizes a thermal bypass valve in the transmission cooler lines. During the fill procedure, you must run the vehicle long enough to get the transmission warm enough to open this bypass valve, purging any trapped air from the cooler. Once purged, let the transmission cool back down to the 30°C–50°C window before performing your final fluid level check.
• Cooler Line Flush is Mandatory: Debris from the old transmission gets trapped in the cooler and lines. If you do not flush them thoroughly with a proper flushing agent, that debris will be pumped directly into your replacement transmission, causing immediate contamination and likely failure.

Easy to get right once you know them:

• Using the Wrong Fluid: Attempting to save money by using cheap multi-vehicle ATF or older Chrysler ATF+4. The ZF 8HP70 is incredibly sensitive to fluid viscosity and friction modifiers. Using non-spec fluid will cause immediate clutch slippage, harsh shifting, torque converter shudder, and will void your warranty.
• Reusing the Old Plastic Pan/Filter: Attempting to save money by reusing the plastic pan is a major mistake. The integrated filter is likely holding debris from the donor vehicle's 109,000 miles of operation, which will restrict fluid flow and destroy the replacement unit.
• Attempting a 'Plug-and-Play' Install: Assuming you can simply bolt the transmission in and drive away. Without programming the integrated TCM to your vehicle's VIN, the vehicle's computers will refuse to communicate, locking the transmission in limp mode or preventing it from shifting out of Park.
• Improper Fluid Leveling: Checking the fluid level while the vehicle is on ramps or not running. If the engine is off when you remove the fill plug, several quarts of fluid will pour out, leaving the transmission severely underfilled and causing immediate gear slippage and clutch damage upon startup.
• Skipping the Cooler Flush: A buyer may think blowing compressed air through the lines is sufficient. It is not. Metal shavings and clutch material from the old unit will remain and contaminate the replacement transmission, leading to a quick 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: