Maddog 4L80E Rebuilt Transmission — 1200HP Build with Billet Torque Converter
Rebuilt Stronger. Reinforced. Backed by a 1-Year Unlimited-Mileage Warranty.
Built to your application. Every Maddog 4L80E is assembled to match the truck, van, SUV, or swap it's going into — 2WD or 4WD, gas or diesel. Tell us the vehicle and we configure the correct tailhousing and output. No guesswork, no wrong-fit returns. What You're Getting
- Fully rebuilt GM 4L80E rated to 1200 horsepower — a true heavy-duty performance build, not a stock reman.
- Converter up to a 2500 stall included — matched to your application and stall needs.
- 1-Year Unlimited-Mileage Warranty — drive it like you mean it.
- Assembled and tested in-house by Maddog Transmissions (Alpharetta, GA — 2,300+ sold, 98%+ positive since 2017).
How It's Rebuilt Stronger
We tear every unit down to the bare case, inspect, and rebuild it with upgraded internals that take it well past factory spec — roughly 40% stronger than a stock 4L80E:
- Borg Warner high-performance clutches for increased holding capacity
- Billet pump rings for stable line pressure under load
- TransGo shift kit / boost valve for firmer, more durable shifts
- Heavy-duty pistons & reinforced drums
- Billet torque converter for clean lock-up and high-HP holding power
- New frictions, steels, bushings, seals, and gaskets throughout
Fits GM 4L80E Applications
The 4L80E is GM's heavy-duty 4-speed automatic. Commonly found behind big-block and diesel powertrains. Built to fit applications such as:
- Chevy / GMC C/K, Silverado & Sierra 2500 / 3500
- Suburban, Tahoe, Yukon & full-size SUVs
- Chevy Express / GMC Savana vans
- 7.4L 454 & 8.1L big-block, 6.5L Turbo Diesel
- LS / LSX engine swaps and custom high-HP builds
Not sure if it fits your exact vehicle? Message us with your year, make, model, and engine before buying — we'll confirm the correct configuration.
Shipping & Returns
- Fast, secure freight shipping — crated and protected. For shipping to the Eastern and Central Time Zones it is free shipping to a commercial business address and $125.00 to a residence. For Mountain and Pacific Time Zones, North Dakota, South Dakota and Nebraska shipping to a commercial business is $295.00 additional and shipping to a residence is $325.00 additional.
- 1-Year Unlimited-Mileage Warranty included.
- Questions before or after the sale? Message us anytime — real builders, fast answers.
Maddog Transmissions — Rebuilt the Right Way.
2,300+ units sold • 98%+ positive • Building strong since 2017
