Dodge G56 Transmission

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Convert your Dodge G56 to an Allison

Transform Your Drive: Making the Switch to an Allison 1000PK Transmission

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Revolutionize your driving experience with the Dodge G56 to Allison 1000PK transmission conversion! Say goodbye to compromised performance and frequent maintenance and embrace the unparalleled durability and functionality of the Allison 1000PK. Renowned for its remarkable strength, unmatched fuel efficiency, and advanced control system, this conversion will transform your Dodge from a hard-working truck into a performance powerhouse. Whether you're hauling heavy loads, traversing rough terrains, or simply cruising the open road, the smooth-shifting and responsive Allison 1000PK transmission promises to redefine your ride and elevate your driving experience to a new level of excellence. Make the switch today and feel the difference an Allison can make.

NV5600 Transmission: An Overview, Key Features, and Common Concerns

Overview of the NV5600 Transmission

The G56 is a six-speed manual transmission designed and manufactured by Mercedes-Benz, but heavily associated with Dodge Ram trucks, where it has been the flagship manual transmission since 2005. Engineered for pairing with the revered Cummins turbodiesel engine in Dodge Ram 2500 and 3500 series trucks, this transmission is celebrated for its balance of performance and reliability. It is robust enough to handle substantial torque outputs, making it a top choice for heavy towing and extensive hauling tasks.

Featuring fully synchronized gears, the G56 offers smooth and precise shifting, enhancing the driver's control over the vehicle. With a strong cast aluminum case and a compact design, the G56 is constructed to withstand harsh conditions and prolonged use, striking a fine balance between resilience and practicality. It offers a flexible gear ratio spread, which allows for fuel-efficient highway cruising while retaining the low-end power required for significant towing and payload capacities.

Nevertheless, as automatic transmissions continue to dominate the truck market, the G56 holds a special place in the hearts of purists who yearn for a hands-on driving experience. It appeals to drivers who value the tactile engagement and immediate control only a manual transmission can provide. For those willing to forego the convenience of an automatic transmission for a more connected and spirited driving experience, the G56 remains an enduring and treasured option.

G56 Features

The G56 transmission, designed specifically for heavy-duty trucks, most notably the Dodge Ram 2500 and 3500 series, is notable for its strong and reliable design. Here are some key features that make the G56 stand out:

  • High Torque Capacity: The G56 is crafted to manage high levels of torque, making it ideal for towing and hauling substantial loads, a perfect match for the Cummins turbodiesel engines.
  • Fully Synchronized Gears: The G56 features full synchronization, allowing for smoother and more precise shifts, enhancing the driving experience.
  • Durable Construction: With its cast aluminum case, the G56 is built for durability, designed to endure the challenges of heavy-duty truck use.
  • Flexible Gear Ratio Spread: The G56 offers a versatile range of gear ratios, which allows for substantial towing power and fuel-efficient highway operation.
  • Clutch Engagement: The G56 often employs a dual-disc clutch, which allows for strong and dependable engagement, essential for high-torque applications.
  • Driver Engagement: As a manual transmission, the G56 delivers a level of driver involvement that is unmatched by automatic counterparts, creating a true connection between driver and vehicle.
  • Aftermarket Support: Its longstanding presence in the market ensures robust aftermarket support for the G56, with a wide array of parts and upgrade options that allow owners to further tailor and enhance their transmission’s performance.

In summary, the G56 is a reliable, capable, and versatile manual transmission designed to meet the demanding requirements of heavy-duty truck applications. Its features are engineered to offer drivers precise control, impressive towing capacity, and durable performance under a myriad of conditions.

G56 Common Issues and Signs of Failures

While the G56 transmission is known for its strength and reliability in heavy-duty applications, it is not immune to potential issues. Below are some common problems associated with the G56 transmission, along with signs that it might be failing:

  • Synchro Wear: Prolonged use can lead to wear on the synchronizers, resulting in challenging shifts, gears grinding during changes, or gears unexpectedly slipping out of position.
  • Clutch Problems: The high torque that this transmission is designed to handle may lead to clutch wear or failure, indicated by shifting issues or a complete loss of drive.
  • Bearing Failures: The bearings in the G56 can wear over time, producing noisy operation or grinding sounds when the clutch is engaged or disengaged.
  • Oil Contamination and Lubrication Issues: Maintaining the proper fluid is vital for the G56. Incorrect or contaminated fluid may lead to increased wear and possible failure, with signs including noisy operation, difficult shifting, and overheating.
  • Input Shaft Wear or Breakage: Excessive loads can stress the input shaft, possibly leading to noisy operation in certain gears or a complete loss of drive.
  • Overheating: Excessive heat, often resulting from heavy towing and hauling, can lead to warped components, fluid breakdown, and eventual transmission failure.

Regular maintenance, including using the correct transmission fluid and replacing worn components as necessary, can significantly extend the life of a G56 transmission and mitigate many of these issues. Consulting with a professional mechanic or transmission specialist when experiencing any of these symptoms is highly advised to diagnose and address the problem before it leads to a complete transmission failure.

Your Guide to Rebuilding, Replacing, and Upgrading to an Allison Transmission

Rebuild, Replace, Converting to an Allison

Convert to Allison

Converting to an Allison 1000PK Transmission

Converting from the G56 to an Allison 1000PK transmission is a complex process, requiring careful planning, specialized tools, and expertise in transmission swaps. The conversion encompasses more than just the physical transmission, as you’re transitioning from a manual to an automatic system. Here's an outline of the steps involved:

  1. Research and Planning

    • Determine the compatibility of the Allison 1000PK with your vehicle's engine and drivetrain.
    • Ensure you have access to any necessary custom parts or kits designed for this conversion.
    • Compile a comprehensive list of parts and tools required for the job.
  2. Acquire Necessary Parts

    • Purchase the Allison 1000PK transmission.
    • Acquire a new or modified bell housing compatible with your engine.
    • Obtain a suitable transmission control module (TCM) for the Allison.
    • Get any required wiring harnesses, adapters, and connectors.
    • Source an upgraded or suitable transmission cooler.
  3. Removal of G56

    • Disconnect the battery.
    • Drain the transmission fluid.
    • Disconnect the transmission linkage, driveshaft, and any associated wiring or hydraulic connections.
    • Remove the G56 transmission from the vehicle.
  4. Preparation and Modification

    • Check the vehicle's transmission tunnel for adequate space. Modify or fabricate as necessary to accommodate the Allison 1000PK.
    • If the existing motor mounts, crossmembers, or transmission mounts are incompatible, install or fabricate new ones.
  5. Install the Allison 1000PK

    • Position the new transmission using a transmission jack and bolt it to the engine using the appropriate bell housing.
    • Ensure all connections are secure, including any mechanical linkage or hydraulic lines, if applicable.
  6. Electronics and Wiring

    • Install the TCM in an appropriate location, typically within the vehicle's cabin or engine bay.
    • Route and connect the wiring harness, ensuring all connections are secure.
    • Integrate the Allison's electronics with the vehicle's existing electrical system, ensuring the TCM communicates correctly with the engine control unit (ECU).
  7. Cooling System Installation

    • Install the transmission cooler, ensuring it’s adequately positioned for airflow.
    • Connect the transmission cooling lines between the Allison 1000PK and the cooler.
  8. Drive Shaft and Final Connections

    • Depending on the length adjustment requirements, either modify the existing driveshaft or obtain a custom one.
    • Install the driveshaft, ensuring it's correctly aligned and securely connected at both ends.
  9. Fluids and Testing

    • Fill the Allison 1000PK with the recommended transmission fluid.
    • Reconnect the battery.
    • Start the vehicle and test all gear positions for correct operation.
    • Take the vehicle for a test drive, ensuring the transmission shifts smoothly and the TCM functions correctly.
  10. Final Adjustments

    • After the test drive, check for any leaks, noises, or irregularities.
    • Make any necessary adjustments to the linkage, wiring, or other components.

Documentation and Legal Considerations:

  • Ensure all changes to the vehicle are documented for future reference or resale.
  • Check with local regulations to ensure the conversion is compliant with emissions, safety, or other legal requirements.

Due to the complexity of this conversion, it's highly recommended to work with a mechanic or shop that has experience with transmission swaps, especially when transitioning from manual to automatic systems. Properly executed, this conversion can result in a vehicle that leverages the reliability and performance of the Allison 1000PK.

NV5600 Rebuild

Rebuilding the Dodge G56 Transmission

Rebuilding a Dodge G56 transmission is a detailed and meticulous process that requires a good understanding of transmission components, as well as access to specialized tools. The goal of a rebuild is to restore the transmission to optimal working condition by replacing worn or damaged parts. Here's a step-by-step outline of the process:

  1. Preparation and Safety: Make sure the work area is clean and organized. Disconnect the battery of the vehicle, and ensure you have all necessary tools and parts before starting.
  2. Disassembly: Carefully disassemble the G56 transmission, organizing and inspecting all components as they are removed. Take note of any visibly worn or damaged parts.
  3. Cleaning: Clean all disassembled parts thoroughly with a parts cleaner solution or solvent. This is crucial for revealing any hidden wear or damage.
  4. Inspection and Assessment: Closely inspect all components, including gears, bearings, synchronizers, shafts, and seals for wear or damage. Use this inspection to compile a list of parts that need replacement.
  5. Acquire Replacement Parts: Based on the inspection, purchase the necessary replacement parts. This will likely include bearings, seals, gaskets, and potentially gears or synchronizers.
  6. Reassembly with New Parts: Carefully reassemble the G56 transmission, replacing the worn or damaged parts with the new components. Pay close attention to the reassembly order and torque specifications for all bolts and fasteners.
  7. Gear and Bearing Preload Setting: Set the preloads for bearings as per the manufacturer’s specifications. This is a critical step to ensure the transmission operates smoothly and without excessive wear.
  8. Sealing and Gasket Installation: Install new seals and gaskets during reassembly to prevent any fluid leaks. Make sure all surfaces are clean and flat before installing the gaskets.
  9. Final Assembly and Inspection: Once the G56 is reassembled, double-check all components, fasteners, and settings. Make sure everything is installed correctly and torqued to the proper specifications.
  10. Reinstallation of the Transmission: Carefully reinstall the rebuilt G56 transmission back into the vehicle, ensuring that all connections are secure and properly torqued.
  11. Refill with Transmission Fluid: After the transmission is reinstalled, fill it with new, clean transmission fluid to the proper level as per the manufacturer’s specifications.
  12. Testing: Reconnect the battery and start the vehicle. Carefully test all gears under controlled conditions. Listen for unusual noises and feel for smooth shifting without grinding.
  13. Road Test: After the initial tests are successful, take the vehicle for a test drive under various conditions. Pay attention to the shifting behavior of the transmission and ensure that it operates smoothly and responsively.
  14. Final Adjustments and Checks: After the road test, recheck the fluid levels and look for any signs of leaks or unusual noises. Make any necessary adjustments based on the road test feedback.
  15. Documentation: Keep detailed records of the rebuild process, including parts replaced and any issues encountered. This documentation can be invaluable for future maintenance or repair.

Please note that rebuilding a transmission is a highly technical task that generally requires a skilled mechanic or experienced DIYer. Specialized tools and manuals specific to the G56 are often necessary. Always refer to a service manual for the most accurate and detailed information.

Replace NV5600

Replacing the Dodge NV5600 Transmission

Replacing a G56 transmission involves removing the old unit from a Dodge vehicle and installing a new or rebuilt transmission. While a trained mechanic usually performs this task, an experienced DIYer with the right tools can also attempt it. Here is a step-by-step outline of the process:

  1. Preparation and Safety: Ensure the work area is clean and well-lit. Disconnect the battery of the vehicle to prevent electrical issues. Gather all the necessary tools and parts before starting, and secure the vehicle with jack stands or a lift.
  2. Removal of Old Transmission: Begin by draining the transmission fluid and removing the driveshaft(s). Disconnect the shifter, electrical connections, clutch linkage, and any exhaust components that may be in the way. Support the transmission with a jack and remove the bolts securing it to the engine. Carefully lower and remove the transmission from the vehicle.
  3. Inspection of Clutch and Flywheel: With the transmission removed, it’s a good opportunity to inspect the clutch and flywheel for wear or damage. Replace these components as necessary.
  4. Preparing the Replacement Transmission: Before installation, ensure the replacement G56 transmission is in good condition. This might be a rebuilt unit or a new one. Check that it is clean, and consider replacing any accessible seals or gaskets.
  5. Installation of New or Rebuilt Transmission: Carefully lift and align the replacement transmission to the engine. Make sure the input shaft slides smoothly into the clutch disc and pilot bearing. Secure the transmission to the engine with the appropriate bolts, torqued to the manufacturer's specifications.
  6. Reconnecting Components: Reattach the shifter, electrical connections, clutch linkage, and any other components that were disconnected. Reinstall the driveshaft(s) and any exhaust components that were removed.
  7. Refill with Transmission Fluid: After the new or rebuilt G56 transmission is installed, fill it with new, clean transmission fluid to the proper level as per the manufacturer’s specifications.
  8. Testing: Reconnect the battery and start the vehicle. Test all gears under controlled conditions. Listen for unusual noises and feel for smooth shifting without grinding.
  9. Road Test: Take the vehicle for a test drive under various conditions. Pay attention to the shifting behavior of the transmission and ensure that it operates smoothly and responsively.
  10. Final Adjustments and Checks: After the road test, recheck the fluid levels and look for any signs of leaks or unusual noises. Make any necessary adjustments based on the road test feedback.
  11. Documentation: Keep detailed records of the replacement process, including the reason for replacement, the source of the new or rebuilt transmission, and any issues encountered. This documentation can be invaluable for future maintenance or repair.

Please note that replacing a transmission is a complex and challenging task. It generally requires a skilled mechanic or an experienced DIYer with access to specialized tools. Always refer to a service manual for the most accurate and detailed information, and consider seeking professional help if needed.

Benefits of converting to an Allison 1000PK Transmission

Converting from a Dodge G56 transmission to an Allison 1000PK automatic transmission can bring several benefits, depending on the specific needs and use of the vehicle. Here are some notable advantages of making such a conversion

Enhanced Durability and Reliability

The Allison 1000 series transmissions are renowned for their durability and ability to handle high torque outputs. For truck owners who use their vehicles for heavy towing or hauling, an Allison 1000PK can offer a level of reliability that exceeds that of the G56.

Automatic Transmission Convenience

The Allison 1000PK is an automatic transmission, which makes driving more convenient, especially in heavy traffic or over long distances. For those who prefer not to manually shift gears, this can be a significant advantage.

Improved Towing Performance

Allison transmissions are designed for heavy-duty applications and are often chosen for their superior towing capabilities. The 1000PK can handle heavy loads with ease, often outperforming manual transmissions like the G56 in towing scenarios.

Potential for Better Fuel Efficiency

The Allison 1000PK, with its advanced torque converter and gear ratios, may offer better fuel efficiency under certain conditions when compared to the G56 manual transmission.

Lower Maintenance

Automatic transmissions like the Allison 1000PK can, in some cases, require less frequent maintenance than manual transmissions. There is no clutch to wear out, which can result in less frequent service intervals.

Resale Value

Having an Allison transmission in a truck can potentially increase its resale value, especially for buyers looking for a vehicle with proven heavy-duty capabilities. The Allison name carries weight in the trucking industry, and prospective buyers may view it as a premium feature.

Adaptability for Different Applications

The Allison 1000PK is designed to be versatile and can be adapted for various uses, including commercial and recreational towing, making it a flexible option for various types of truck owners.

What's included in an Allison Conversion kit?

We provide everything you will need to get the swap done right

Duramax with Allison Transmission
    • Kit Includes
    • Transmission
      Torque Converter
      Wiring Harness
      Flex Plate adapter
      Transfer Case
      Mounting Kit
      Cooling Kit
      Digital Display
      Allison TCM
      CAC TCM
Allison 1000PK Transmission

Allison 1000PK Transmission

Upgrade your vehicle's capabilities with the esteemed Allison 1000PK Transmission. You have the option to either include this component in your kit purchase or use your own pre-acquired Allison 1000PK transmission. To cater to your needs, we also provide transmission rebuilding services. Explore a comprehensive selection of other Allison transmissions here that we can expertly convert.

How to determine the Right Torque Converter

Maximizing Performance: Using Tire Diameter and Gear Ratio Calculations to Choose the Ideal Torque Converter

How to determine the right torque converter


Converting your Dodge Ram's transmission to an Allison can result in numerous benefits including improved durability, enhanced towing capability, increased fuel efficiency, and smoother gear shifts, thus optimizing your vehicle's performance.

Most Dodge Ram models can benefit from an Allison transmission conversion, but it's advisable to consult with a specialist to ensure compatibility with your specific model.

Yes, with the right adapters, your existing Dodge Ram transfer case can be utilized in an Allison conversion.

The Allison 1000 series is a popular choice for Dodge Ram vehicles due to its reliability and performance, but the best option depends on your particular needs and vehicle model.

The conversion process involves removing your Dodge Ram's current transmission, fitting the Allison transmission with the necessary adapters, and installing it. The wiring harness, TCM, and other components are also adjusted accordingly.

Yes, an Allison transmission is designed to provide smoother shifts, increased durability, and better fuel efficiency, all of which contribute to improved vehicle performance.

An Allison conversion kit typically includes components such as the transmission (if chosen), TCM, torque converter, wiring harness, adapters, and other necessary parts for the conversion.

You have the option to either provide your own Allison transmission or include it with your conversion kit purchase.

While it's possible for experienced individuals to do the conversion, it's generally recommended to hire a professional to ensure the job is done correctly and safely.

The conversion time can vary based on the vehicle and the specific conversion kit. On average, it might take a few days to complete.

An Allison conversion could affect your vehicle's warranty depending on the specific terms of your warranty agreement. We recommend checking with your warranty provider before proceeding with the conversion.

If you face any problems after the conversion, it's best to contact your conversion specialist for troubleshooting assistance or potential service needs.

Yes, an Allison transmission from another vehicle can be used, provided it's compatible with your Dodge Ram model. Ensure to consult with your conversion specialist before proceeding.

Yes, we do offer rebuilding services for Allison transmissions, ensuring your transmission is operating at peak performance.

The cost can vary significantly depending on the specific Allison model, whether you're providing the transmission or purchasing it as part of the kit, and any additional services required. Please contact us directly for a more precise estimate.

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