6L80 6-Speed Automatic Transmission Assembly for 2014-2020 Chevrolet & GMC

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

• Verify the 8th digit of the VIN is C or H (confirming the 5.3L V8 L83 engine).
• Confirm the vehicle is a 4WD/4x4 model with a front driveshaft and transfer case.
• Check the silver Service Parts Identification sticker in the glove box for RPO code MYC.

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

Special tools this job needs:

• transmission jack
• torque converter holding bracket
• J-46409 torque converter alignment/seating tool
• J2534 pass-thru programming device / GM MDI2
• stable battery maintainer
• E12 external Torx socket
• transmission cooler line disconnect tools

Budget for these consumables at install:

• Dexron VI Automatic Transmission Fluid (12.2 to 12.5 quarts for dry fill)
• ACDelco transmission filter (GM Part #24236933)
• Pan gasket (GM Part #24224781)
• Front pump/torque converter seal
• High-pressure hot flush agent (e.g., Lubegard Kooler Kleen)
• Exhaust manifold-to-pipe gaskets

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

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

The internal TEHCM must be flashed with the buyer's vehicle-specific VIN and calibration file using a J2534 pass-thru device and GM SPS2/TIS2Web subscription. A 'Service Fast Learn' (adaptive relearn) must also be executed using a professional scan tool to calibrate the solenoids.

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

• Torque Converter Seating: Must rotate and push the converter until it clicks/drops three distinct times. If not fully seated, bolting the transmission to the engine will crush the front pump rotor.
• Thermal Bypass Valve Upgrade: Replace the original 194°F thermostat with the updated GM 158°F thermostat (GM Part #85585333) to prevent overheating.
• Exhaust Y-Pipe Removal: Exhaust Y-pipe runs directly under the pan on 4WD models and must be lowered. Spray bolts with penetrating oil in advance.
• Cooler Line Alignment: Ensure lines are not twisted or kinked to prevent restricted fluid flow and DTC P27EC.
• Fluid Level Check Procedure: No traditional dipstick. Must check with vehicle running, level, and fluid temperature between 160°F and 200°F (or 86°F to 122°F depending on spec) via the level-check plug in the pan.

Easy to get right once you know them:

• Driving without programming: Assuming the transmission is plug-and-play, leading to immediate clutch destruction.
• Reusing a contaminated cooler: Skipping the cooler line flush after a torque converter failure, which pumps metal debris back into the new unit.
• Incorrect fluid level check procedure: Checking fluid cold or with the engine off, resulting in severe underfill.
• Forcing the transmission into place: Using bellhousing bolts to draw the transmission to the engine when the torque converter is not fully seated, cracking the pump housing.
• Skipping torque converter replacement: Reusing a worn or contaminated torque converter.

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: