6L80E 6-Speed Automatic Transmission Assembly for 2015-2016 Chevrolet & GMC

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

• Check your VIN's 8th digit: Confirm that the 8th digit is 3 (designates the 3.6L LFX V6 engine).
• Verify your drivetrain: Confirm you have a front driveshaft and a transfer case bolted directly to the rear of your transmission.
• Locate your transmission RPO code: Confirm the code MYB is on the silver Service Parts Identification sticker in the glove box.

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

Special tools this job needs:

• Heavy-duty transmission jack
• Engine support fixture or heavy-duty jack stands
• Transmission cooler line flush equipment
• GM-compatible J2534 pass-through programming tool or dealer-level scan tool (such as GM MDI)
• Specialized fluid pump or fill tool

Budget for these consumables at install:

• Dexron VI (6) Automatic Transmission Fluid (Mobil 1 Synthetic LV ATF HP Blue Label highly recommended)
• New transmission filter and pan gasket
• New torque converter/front pump seal
• Two new GM output shaft O-rings (Part # 24251228)
• High-temperature wheel bearing grease
• Transmission line flush solvent

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

What’s involved: VIN-Specific TCM Programming & Adaptive Relearn

The 6L50 uses an internal Transmission Control Module (TCM). Because this is a used unit, the TCM is currently programmed to the donor truck's VIN. You must have a professional reprogram the TCM to match your truck's VIN using GM's Service Programming System (SPS). Additionally, your mechanic must perform a TCM Adaptive Relearn using a compatible scan tool to reset shift pressure parameters.

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

• Torque Converter Seating (Critical): Must drop back into the case three distinct times (three 'clicks') during rotation. If not fully seated, bolting the transmission to the engine will crush and crack the internal pump rotor.
• Fluid Level Check Procedure (No Dipstick): Must be checked via a standpipe in the bottom of the pan with the engine running and fluid temperature between 86°F to 122°F (30°C to 50°C).
• Output Shaft Greasing: Clean splines, install updated O-rings, and apply a liberal coat of high-temperature grease to prevent moisture from seizing or stripping the splines.
• Cooler Flush is Critical: Failing to flush the cooler lines is a leading cause of repeat failures.

Easy to get right once you know them:

• Ordering for the Wrong Engine: Buying a 6-speed transmission from a 2.5L 4-cylinder or 2.8L diesel Colorado, which have different bellhousing patterns and internal calibrations.
• Ordering a 2WD Transmission for a 4x4 Truck: 2WD versions have a much longer output shaft and cannot be bolted to a 4x4 transfer case without a complete teardown.
• Driving Before Programming: Attempting to drive immediately without programming the TCM to the VIN, which triggers immediate limp-mode codes and can burn up internal clutches.
• Checking Fluid with the Engine Off: Removing the fluid level check plug while the engine is off will cause several quarts of fluid to pour out, leaving the transmission severely underfilled.

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: