The 10-speed 10L80 automatic in the 2019+ T1XX has several known issues. Here’s a comprehensive guide to the most common problems and solutions.
Problem 1: TCC Shudder (Most Common)
Already covered in our 10-Speed Shudder thread – the vibration at 40–65 mph is the #1 complaint.
Fix: TCM calibration update from dealer + ACDelco Dexron VI fluid service + Lubegard Shudder Fixx.
Problem 2: Gear Hunting at Cruise
The 10-speed can feel like it’s constantly searching for the right gear, especially at light throttle on the highway.
Fix: GM TSB updates modify shift programming. Dealers can apply these. A custom tune can also address shift behavior.
Problem 3: Hard Shift or Clunk from Stop
Some T1XX owners report a hard shift or clunk when pulling away from a stop, particularly in cold weather.
Fix: Allow the transmission to warm up fully before aggressive acceleration in cold weather. If persistent, TCM calibration update.
Problem 4: 1-2 Shift Hesitation
Hesitation or roughness on the 1-2 upshift, particularly when cold.
Fix: Common in early production units. Addressed by calibration updates and allowing full warm-up.
General Maintenance:
- Fluid service: Every 45,000 miles normal, every 30,000 under towing
- Use only ACDelco Dexron VI ATF
- Transmission pan drop (approx 6–7 quarts) + refill is standard service
When to See a Dealer:
If issues persist after fluid service and calibration updates, consult a dealer – GM has been addressing 10-speed issues under powertrain warranty.
Have you had 10-speed issues on your T1XX? What was the fix?