10-Speed Automatic Transmission Assembly for 2022-2026 Cadillac, Chevrolet, & GMC

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

• Verify shifter type: Must be Electronic Precision Shift (ETRS / shift-by-wire) with console buttons, not a mechanical column shifter.
• Scan or read RPO codes on the driver's side B-pillar QR code or glove box sticker to confirm 'MHS' or 'MQB'.
• Confirm engine size is 6.2L V8 (L87) or 5.3L V8 (L84) by checking the emissions label or the 8th digit of the VIN.
• Confirm 4WD/4x4 drivetrain: Must have front driveshafts and a transfer case.

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

Special tools this job needs:

• High-lift transmission jack with safety straps
• GM transmission line disconnect tool (Ford 307-569 or equivalent J-tool)
• Exhaust pipe hanger/removal tools
• Professional-grade OBD2 scan tool capable of GM SPS2 programming and Transmission Fast Learn

Budget for these consumables at install:

• ACDelco DEXRON ULV (Ultra-Low Viscosity) ATF (GM Part Number 19352619 or Mobil 1 Synthetic LV ATF HP)
• Internal transmission filter (GM Part Number 24294355 / ACDelco TF937)
• Pan gasket (GM Part Number 24297886)
• One-time-use stretch filter bolts
• Front pump/torque converter seal
• Transfer case input seal
• Transmission cooler line flush solvent
• Right-hand exhaust flange gasket (GM 61074)
• Left-hand exhaust flange gasket (GM 61089)

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

What’s involved: VIN-specific programming, TCM adaptive relearn (Transmission Fast Learn), and TUN (Transmission Unique Number) / PUN (Part Unique Number) calibration write.

The 10L80 uses a flow-characterized valve body. The replacement unit's TUN/PUN must be programmed into the vehicle's computer using GM Techline Connect (SPS2) or a high-end J2534 pass-thru tool. Driving without programming will cause immediate harsh shifting, shift flares, and permanent clutch pack damage.

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

• Torque converter must be fully seated in multiple stages. Forcing the transmission to bolt to the engine when the converter is not seated will crack the front pump rotor and destroy the unit.
• The exhaust Y-pipe must be dropped to clear the transmission pan; exhaust bolts are highly prone to seizing.
• The internal thermal bypass valve blocks fluid flow to the cooler below 143°F (61°C). External lines must be bypassed or removed to perform a proper cold flush.
• There is no dipstick. Fluid level must be checked via the level-check plug on the side of the pan with the vehicle level, engine idling, and fluid temperature strictly between 167°F and 176°F (75°C to 80°C).
• An adaptive relearn drive cycle must be followed gently for the first few hundred miles after the in-shop fast learn is complete.

Easy to get right once you know them:

• Ordering an ETRS (shift-by-wire) transmission for a cable-shift column vehicle or vice versa.
• Skipping the critical TUN/PUN programming and attempting to drive immediately, which burns out clutches within miles.
• Using incorrect fluid such as Dexron VI or generic multi-vehicle ATF instead of the required DEXRON ULV.
• Reusing one-time-use torque-to-yield filter bolts, which can back out or snap, causing the filter to drop and starve the pump.
• Skipping the mandatory transmission cooler and line flush, leading to immediate contamination from old debris.

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: