48RE Transmission Stage 4 1,000HP+ w/ Sonnax Oversized Input Shaft

Randy’s Stage 4 48RE Transmission – Unleash the Ultimate Power

For the true performance enthusiast who demands nothing less than the best, Randy’s Stage 4 48RE transmission is the pinnacle of racing and towing excellence. Rated for 1,000+ HP, this transmission is engineered to deliver unrivaled strength and performance at the track, or wherever you push your truck to the limits.

Race Ready Performance:

This Stage 4 48RE is packed with race-ready features, including our XHD Series Quad Disc Converter, available in two stall options: Stock (Tow/Daily 1800-2000 RPM) and High (Street/Track 2400-2600 RPM). Whether you’re going full throttle on the drag strip or testing your power on the dyno, this converter ensures your truck responds with the power and precision you demand.

Transmission Specs:

 • XHD Series Quad Disc Converter: Available in two stalls—Stock (Tow/Daily 1800-2000 RPM) or High (Street/Track 2400-2600 RPM)—you choose the lockup based on your driving habits.

 • Alto G3 Clutches and Steels: Exclusive to Randy’s, these clutches and steels provide superior holding power and durability, designed for the toughest applications.

 • Alto G3 Power-Packed Overdrive with Custom Pressure Plate: Enhanced for high-torque conditions, ensuring smooth and efficient shifts.

 • TCS Billet Direct Drum Strengthened to handle higher torque and horsepower, improving overall performance.

 • TCS Super Servo, Billet Band Strut, Billet Wedge: Provides unmatched precision and durability for smooth, reliable shifting under pressure.

 • Billet Accumulator: Built to withstand high-pressure environments, extending the transmission’s lifespan.

 • Billet 4.2 Lever: Ensures optimal performance and durability.

 • Sonnax Billet Input Shaft (Oversized): Designed to handle extreme power output, reducing the risk of breaking.

 • Ridged 2nd Gear Band: Improves durability and shifting performance under heavy load.

 • Heavy Duty Direct Drum Piston: Built to handle higher pressures and provide consistent performance under stress.

 • Borg Warner Governor Pressure Solenoid: Ensures precise pressure control for optimized shifting and reliability.

 • High Pressure Transducer: Monitors and regulates pressure levels, ensuring smooth and efficient operation.

 • Heavy Duty Cast Aluminum Deep Pan: Offers increased fluid capacity and cooling for improved transmission life.

 • Maraging Intermediate Shaft: High-strength shaft designed for extreme conditions.

 • Big Daddy Output Shaft: Built to handle massive amounts of torque and horsepower.

 • Custom High Pressure Valve Body: Engineered to deliver high pressure for improved performance and clutch application in demanding situations.

 • PTFE Coated Thrust Washers: Provides reduced friction and wear for longer-lasting performance.

 • Optional Add-On: Upgrade to a full manual valve body for $399, which includes a billet reverse servo, giving you complete control over shifting and lockup.

Proven Power:

This is the exact transmission build that powers our legendary 2006 Ram 3500 "Red Delicious," which put down an astonishing 3,180 HP on June 1, 2024.

It’s the same transmission backing Shawn Baca's "Master Shredder," propelling it to an 8.8 second ¼ mile run at 157 mph during the Ultimate Callout Challenge (UCC). These are the same internals that helped the Industrial Injection drag truck, weighing 5,445 pounds on leaf springs, shatter records with an 8.07 second ¼ mile at 180 mph during the UCC.

Featuring Alto G3 Clutches & Steels 

The Alto G3 line has a long-standing reputation for its strength and reliability in transmission builds. Developed to withstand extreme demands, G3 frictions have become the gold standard for builders who demand durability and consistent performance.

Recognizing the need for a tough, long-lasting transmission solution, we teamed up with Alto to bring a full clutch and steel lineup specifically designed for the 47RE & 48RE. Built with the same trusted G3 technology, this lineup offers unmatched resilience, ensuring your transmission can handle anything you throw at it—whether it’s the heavy demands of towing or the rigors of track racing.

This collaboration between Randy’s and Alto guarantees that your 48RE gets the best in performance, tested and proven under real-world conditions.

Backed by Real-World Testing and Proven Expertise

Since 2008, we have mastered the 48RE transmission. Through years of hands-on experience, we’ve fine-tuned our builds to deliver unmatched durability and performance. When it comes to the 48RE, nobody else comes close.

Our very own Red Delicious (2006 Cummins Dually) started with stock power, but out of a desire to find and eliminate every weak point, we steadily increased its power. Each stage of development allowed us to identify and address vulnerabilities, resulting in a transmission built to withstand anything you can throw at it. Our real-world testing ensures that every transmission we produce is battle-tested and ready for the road or track

Why Choose Randy’s Stage 4 48RE?

Performance perfected. That’s what you get with Randy’s Stage 4 48RE transmission. We’ve invested years of trial and error, pushing our builds to the absolute limit, to bring you the strongest, most reliable 48RE transmission available. This isn’t just a transmission; it’s the culmination of our dedication to providing Cummins owners with the ultimate power and performance.

Buy Now, Pay Later

We know that upgrading your transmission is a big investment and paying all at once can be tough. That’s why we’ve teamed up with Affirm to make it easier for you. With our financing options, you can enjoy the benefits of a top-quality transmission without the stress of a hefty upfront payment. Available exclusively online, just choose Affirm at checkout and spread your payments out over time. Get the performance you need today, and pay at a pace that fits your budget.