8-Speed Automatic Transmission Assembly for 2018-2026 Jeep Gladiator, Wrangler

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

• Confirm the 8th digit of your vehicle's VIN is 'G' or 'S' (verifying the 3.6L Pentastar V6 engine).
• Verify your Jeep is a 4WD model (Command-Trac or Rock-Trac 4x4 system).
• Locate the identification tag on the side of your current transmission case to confirm model 850RE (Sales Code DFT) or part number cross-reference (e.g., 68249553AD).

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

Special tools this job needs:

• Heavy-duty transmission jack
• Flex-head ratcheting wrenches
• Swivel/universal sockets
• Fluid transfer pump
• Professional-grade diagnostic scan tool (wiTECH 2.0, JScan, or AlfaOBD)

Budget for these consumables at install:

• Mopar ZF 8 & 9 Speed ATF (Part number 68218925AB) or ZF Lifeguard 8 / Lifeguard 9
• New transmission pan/filter assembly (Mopar part number 68522534AA or equivalent) and fresh gasket
• Front torque converter seal (front pump input seal)
• Rear output shaft seal (where the transfer case mounts)
• Professional high-pressure transmission cooler and line flush

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

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

The integrated TCM contains the donor vehicle's VIN. To prevent security faults or limp mode, a technician must program your vehicle's VIN into the replacement TCM using a factory-level scan tool (such as wiTECH 2.0) and perform a TCM Quick Learn / Adaptive Relearn. Alternatively, you can swap your original, functioning valve body/TCM assembly into this replacement unit to avoid reprogramming.

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

• Torque Converter Seating: Must verify the torque converter is fully and deeply seated (typically three distinct drops/clicks) before bolting to the engine to avoid cracking the internal oil pump.
• Strict Fluid Leveling Procedure: No dipstick. Must check fluid level with the vehicle perfectly level, engine running, and fluid temperature strictly between 86°F and 122°F (30°C to 50°C).
• Dowel Pin Alignment: Ensure engine block alignment dowel pins are clean and perfectly aligned with the bellhousing to prevent cracking the aluminum case.
• TCM Adaptive Relearn: Must reset the TCM's adaptive memory using a scan tool to prevent harsh, violent shifts from old pressure maps.
• Cooler Line Flush: Mandatory high-pressure flush of the cooler and lines to prevent old debris from contaminating the replacement unit.

Easy to get right once you know them:

• Ordering for the wrong engine (e.g., 2.0L Turbo, 3.0L Diesel, or 4xe/392 V8 models).
• Using generic or ATF+4 fluid instead of the specified Mopar ZF 8 & 9 Speed ATF or ZF Lifeguard 8/9.
• Failing to perform TCM VIN programming and resetting adaptive learning.
• Checking the transmission fluid level with the engine turned off.
• Forcing the transmission onto the engine without fully seating the torque converter, cracking the front pump.

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: