Product description
Recommended to add transmission cooler & Billet Flexplate to order.
Sales Tech will call to verify build details.
Stage 3 Allison Transmission for Chevy & GMC Duramax Pickups
Tow-Ready. Track-Ready. Built for 900 HP.
The Stage 3 Allison transmission is built for Duramax owners who expect serious capability—whether that means hauling heavy equipment or pushing high horsepower at the track. Designed to balance towing strength with performance‑focused responsiveness, this transmission delivers consistent, controlled power under demanding conditions. With a rating of up to 900 horsepower, it’s a top-tier upgrade for drivers who want both reliability and performance.
Engineered for Power, Precision, and Durability
Featuring upgraded clutch systems, billet components, and custom‑machined pressure plates, the Stage 3 Allison is designed to manage extreme torque while maintaining smooth, predictable shifting. Every part is selected to enhance durability and ensure efficient power delivery, giving your truck the confidence to handle intense towing or high‑RPM racing.
Premium Components for Maximum Strength
Raybestos or ALTO G3 C‑3 & C‑4 Torque Kit with custom‑machined pressure plates for increased clutch capacity
LML‑Style Pistons & Return Springs for improved performance under heavy load
Raybestos or ALTO G3 C‑1 & C‑2 Torque Kit for enhanced holding power and heat resistance
Ratio Tek Pressure Upgrades to stabilize hydraulic performance and improve reliability
Transgo Trim Valves for refined pressure control and smoother shifting
New Torrington Bearings to reduce friction and extend component life
Randy’s Torque Converter with Billet Stator, available with custom stall options for towing or racing setups
Billet Input Shaft for superior torque handling
Billet C‑2 Hub engineered for extreme power applications
Heavy‑Duty Cast Aluminum Deep Pan for improved cooling and increased fluid capacity
Why Choose Randy’s Stage 3 Allison?
Randy’s Transmissions is known for building high‑performance units that hold up under real‑world abuse. The Stage 3 Allison is thoroughly tested to ensure it performs consistently whether you’re towing heavy loads or making hard passes at the track. We only release products that meet our highest standards, giving you a transmission built for serious work and serious power.
Driven by Experience and Continuous Development
The Stage 3 Allison is the result of years of refinement, hands‑on testing, and performance‑driven engineering. Every component and calibration has been shaped by real‑world data and extensive R&D, ensuring you receive a transmission that delivers exceptional durability and power handling.
1‑Year / 12,000‑Mile Warranty
Your Stage 3 Allison transmission is backed by a 1‑year, 12,000‑mile warranty, giving you confidence that your investment is protected. Whether you’re towing, racing, or daily driving with added power, you can count on dependable performance and support from a team committed to quality.