4L65E

The Gearstar MOPAR 4L65E automatic transmission is expertly engineered for seamless compatibility with Mopar engines, ensuring a perfect fit with the engine block for optimal performance. Designed as a high-performance transmission, it’s an ideal upgrade for Ram vehicles and a wide range of models from Chrysler, Dodge, and Jeep, making it a versatile solution for drivers who demand heavy-duty capabilities from their automatic transmissions.

Built to handle the toughest conditions, the 4L65E features a robust rear planetary gear set that’s specifically designed to manage high torque and advanced gear ratios. This makes it exceptionally well-suited for trucks and SUVs that require both strength and durability, whether you’re hauling heavy loads or seeking maximum performance on the road.

Features like hardened pump rings, a reinforced trans mount center, and a precision wiring harness ensure that installation is straightforward and that the transmission will deliver reliable performance for years to come.

Basics About the Mopar 4L65E Transmission

Originally an evolution of GM’s legendary 4L60E, the 4L65E transmission was designed to handle greater torque capacity and improved performance. Featuring reinforced internal components, upgraded planetary gearsets, and an advanced electronic control system, it became a go-to choice for builders who demand dependability under high-performance conditions.

For Mopar enthusiasts, Gearstar has adapted the 4L65E to work seamlessly with both modern Mopar Gen III Hemi engines and classic small-blocks. This combination offers the perfect mix of traditional Mopar power and modern overdrive efficiency. Whether you’re building a classic restomod, off-road vehicle, or late-model street machine, the Mopar 4L65E transmission delivers the balance of performance and reliability you expect.

Key Features of the Mopar 4L65E Transmission

Heavy-Duty Construction

The Mopar 4L65E transmission is built with durability in mind. It features hardened input shafts, improved 5-pinion planetary gearsets, and a reinforced reaction sun shell, all designed to handle torque levels up to 380–400 lb-ft in stock form, and significantly more when built by Gearstar.

Advanced Electronic Control

Like other “E” series transmissions, the 4L65E uses an electronic control system to manage shift timing, torque converter lockup, and pressure regulation. This ensures consistent performance across driving conditions while allowing tuners to fine-tune the behavior for performance or comfort.

Versatile Adaptability

Our custom Mopar transmission adaptions allow the 4L65E to be installed behind a variety of Mopar engines. Whether you’re running a Gen III Hemi in your modern muscle car or a classic LA-series small-block, Gearstar provides the right adapter systems and torque converters to ensure a perfect mechanical and electronic match.

Efficient Overdrive Gear

The 0.70:1 overdrive gear ratio helps reduce engine RPM at cruising speed, improving fuel economy and engine longevity, offering a major upgrade for older Mopar setups originally equipped with 3-speed automatics.

Precision Assembly and Testing

Every Mopar 4L65E transmission is hand-built by a single master technician and DYNO-tested under load to verify performance, shift quality, and durability. This process ensures that your transmission is ready to handle real-world power right out of the box.

Advantages of the Mopar 4L65E Transmission

Ideal for Restomods and Swaps

The 4L65E transmission is a top choice for Mopar restomod projects, providing the reliability of modern overdrive technology without sacrificing performance. It’s perfect for muscle car builds where maintaining power and drivability is essential.

Increased Strength and Longevity

Compared to earlier versions, the 4L65E incorporates stronger internal components that allow it to withstand higher horsepower and torque loads. Gearstar’s upgraded builds go even further with improved clutches, servos, and custom valve bodies to deliver unmatched durability.

Smooth, Adaptive Shifting

With electronic shift control, the 4L65E delivers crisp, responsive gear changes. Whether you’re cruising the highway or launching hard at the track, the transmission’s adaptive logic ensures optimal performance every time.

Proven Compatibility

The Mopar 4L65E transmission can be configured for a wide range of Mopar engines, making it one of the most versatile performance transmissions available today. Gearstar’s precision adapter systems ensure reliable engagement and torque transfer, even under high stress.

Expert Engineering

Our team of seasoned builders understands the challenges of pairing GM transmission technology with Mopar engines. That’s why each Mopar transmission we produce is designed, tested, and tuned to deliver seamless integration and high performance across all driving conditions.

Frequently Asked Questions About the Mopar 4L65E Transmission

Can you use a 4L65E transmission in a Mopar engine?

Yes, with the proper adapter system, you can absolutely use a 4L65E transmission in a Mopar engine. Gearstar builds custom Mopar 4L65E transmissions specifically for this purpose, engineered to mate perfectly with both classic small-block and modern Gen III Hemi engines. These setups provide the strength and performance of a GM transmission while maintaining Mopar compatibility.

How does the 4L65E pair with a Gen III Hemi engine?

Our Mopar 4L65E transmission is an ideal match for the Gen III Hemi, offering modern overdrive capability and electronic shift control that complements the engine’s high torque output. Gearstar’s custom torque converters and control systems ensure optimal power transfer and reliability.

Is the 4L65E compatible with traditional Mopar small-block engines?

Yes. Gearstar offers 4L65E transmission versions adapted for Mopar small-block engines like the 340, 360, and 318. These setups are perfect for restomod or drag racing applications, giving classic Mopar builds modern shifting precision and improved efficiency.

How much power can the 4L65E handle?

In factory trim, the 4L65E is rated for around 380 lb-ft of torque. However, Gearstar’s upgraded Mopar 4L65E transmissions are capable of handling 500+ horsepower thanks to enhanced clutches, servos, and valve body modifications.

Why choose a Mopar 4L65E from Gearstar?

Every Gearstar Mopar transmission is custom-built to order by a single master technician using only premium components. We offer competitive pricing and all of our transmissions are DYNO-tested to ensure flawless operation and consistent power delivery, giving you the reliability and performance your Mopar build deserves.

Buy a Custom-Built Mopar 4L65E Transmission from Gearstar

If you’re looking for a powerful, reliable Mopar 4L65E transmission, Gearstar delivers the best in craftsmanship and performance. Each transmission is hand-built, tested, and tuned to your vehicle’s specifications, whether it’s a Gen III Hemi street machine or a classic Mopar restomod.

At Gearstar, our transmissions are designed for builders who demand precision, reliability, and proven performance. When you purchase a Gearstar 4L65E, you benefit from the availability of new, OEM parts, comprehensive warranty coverage, and expert consultation to ensure the right fit and performance for your vehicle.

Contact us today to order your custom-built Mopar 4L65E transmission or explore our full line of performance Mopar transmissions engineered for power and longevity.