Product description
Recommended to add transmission cooler & Billet Flexplate to order.
Sales Tech will call to verify build details.
Stage 4 Allison Transmission – Built for Serious Power
Street & Track Dominator for Chevy & GMC Duramax Trucks
The Stage 4 Allison 1000 is engineered for Duramax owners who want uncompromising performance on both the street and the track. Rated for 900+ horsepower, this transmission is designed for drivers who push their trucks to the edge and need a drivetrain that can keep up. If maximum power transfer, durability, and high‑RPM stability are your priorities, the Stage 4 is the top-tier choice.
High‑Output Street & Track Performance
This build combines upgraded clutch systems, billet hard parts, and precision‑machined components to withstand extreme horsepower while maintaining smooth, controlled shifting. Whether you’re launching hard at the track or putting down big power on the street, the Stage 4 Allison is built to deliver consistent performance under the harshest conditions.
Key Features & Performance Components
Raybestos or ALTO G3 C‑3/C‑4 Torque Kit with custom‑machined pressure plates for maximum clutch capacity and holding strength
LML‑Style Pistons & Return Springs for faster, cleaner shifts at high power levels
Raybestos or ALTO G3 C‑1/C‑2 Torque Kit for dependable engagement under heavy load and high RPM
Ratio Tek Pressure Upgrades to stabilize hydraulic pressure and improve reliability under extreme stress
Transgo Trim Valves for refined shift control and consistent pressure regulation
New Torrington Bearings to reduce friction and extend component life
Randy’s Torque Converter with Billet Stator, with custom stall options tailored for street or track setups
Billet Input Shaft, Billet C‑2 Hub & Billet Output Shaft for unmatched torque handling
Billet P‑2 Planet for added strength in high‑horsepower applications
Heavy‑Duty Cast Aluminum Deep Pan for improved cooling and increased fluid capacity
New OE Filters to maintain clean, efficient fluid flow during high‑performance operation
Unleash Maximum Performance
After extensive development and real‑world testing, Randy’s has refined the Stage 4 Allison into a transmission capable of handling extreme horsepower with confidence. Every component is selected to support high‑output builds, ensuring your Duramax performs consistently whether you’re racing or driving aggressively on the street.
Why Choose Randy’s Stage 4 Allison?
Randy’s Transmissions builds performance units that are proven through rigorous testing—not just theory. The Stage 4 Allison has been pushed through countless hours of street, track, and high‑power abuse to ensure it meets the demands of serious enthusiasts. This transmission is the result of years of engineering, refinement, and hands‑on experience, making it the premier choice for drivers who want the strongest possible Allison platform.
1‑Year / 12,000‑Mile Warranty
Your Stage 4 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 big power, you can rely on Randy’s proven durability and customer support. Every unit is built to deliver dependable performance mile after mile.