6L90 Transmission – HD Transmissions That Deliver Under Load

The 6L90 was built for bigger jobs — but it’s also known for big problems. Torque converter failure, fluid breakdown, and harsh shifts aren’t rare. They’re expected.

ACE remanufactures 6L90 units the way your shop needs them: updated, tested, and ready to install. No extra downtime. No return headaches. Just solid solutions for heavy-use platforms.

6L90 Problems We Know You’ve Seen

  • Torque converter clutch failure and metal contamination
  • Cracked bell housings or stator shaft wear
  • Line pressure issues and delayed engagement
  • Shift flare or harsh transitions under load
  • Fluid breakdown in fleet or towing environments

We reman every unit with failure-prone parts replaced and OE updates included. Nothing leaves the floor untested.

What Sets Our 6L90 Builds Apart

  • 🛠️ Fully remanufactured from case to tail
  • 📊 Dyno tested under heavy-load simulation
  • ⚙️ Includes updated valve bodies, converter clutch improvements, and new bushings
  • 🛢️ Included with Mobil 1 synthetic transmission fluid
  • 📦 Same-day shipping on most builds
  • 🛡️ Backed by a 3-year / unlimited mileage warranty

Common Vehicles Running the 6L90

We supply drop-in 6L90 units for:

  • Chevy Silverado HD (2500 / 3500)
  • GMC Sierra HD (2500 / 3500)
  • Chevy Express / GMC Savana 2500 & 3500 Vans
  • Chevy Suburban / Yukon XL (Heavy-Duty Fleet Packages)
  • Some Police / Municipal / Ambulance Chassis

Not sure about fitment or calibration? Call our team. We’ll confirm it in minutes.

Why Fleet & Commercial Shops Trust ACE

  • ✅ More uptime — fewer comebacks and failed installs
  • ⏱️ Save 4–8 labor hours per build vs. internal rebuilds
  • 🔧 Live install support available when your tech needs help
  • 🔁 Transferable warranty builds resale value and trust
  • 💲 18-month warranty option available for price-sensitive fleet jobs

Shop-Tested. Fleet Vehicle Trusted.

  • ✔️ 3-Year / Unlimited Mileage Warranty
  • ✔️ Includes parts, labor, shipping & Mobil 1 fluid
  • ✔️ Nationwide coverage from a real team
  • 💲 Lower-cost option available when needed

Let’s Get Your Next 6L90 Out the Door

👉 Request a quote in under a minute
👉 Talk to a real tech to match the unit
👉 Most 6L90s ship same-day

The 6L90 doesn’t need to be a headache. Put a reman in your shop that you can trust.