Advantages of the Allison 5 or 6 Speed Transmission for Cummins Engines

August 20, 2023

Why Opt for an Allison 5 or 6 Speed Transmission with your 12V, 24V 5.9L, or 6.7L Cummins?

The history of automatic transmissions, especially from 1989 to 2002, shows a pattern of outdated technology. The 47 RH and later the 48-RE transmissions took inspiration from the 727 Torqueflight Chrysler transmission, which was never tailored for the diesel market. Despite modifications and evolutions, the legacy technology issues persisted, making these options suboptimal for those looking for smoother and more consistent shifting experiences, especially in towing scenarios.

  • The older automatic transmissions used bands, hydraulic throttle valves, and governor pressure for shift timing.
  • The 48-RE, for instance, had uneven gear spacing. The jump into the overdrive was particularly noticeable.
  • Its torque converter felt more like an afterthought, leading to inconsistent TCC shifts.
  • While upgrades are possible, they are limited by the design constraints of the transmission itself.

Examining the 68-RFE Transmission

While the 68-RFE transmission boasts a better gear split, its merits tend to end there. Designed to be cost-effective, many of its components require upgrades to match the demands of modern engines and towing needs. Strikingly, its design lineage can be traced back to a Dodge Caravan transmission from 1989. Although strengthening is possible, the Allison conversion offers a more robust solution.

The Aisin Dilemma

For those with Aisin variants like the 68-RC, AS-69RC, or AS-66 RC, the Allison is a no-brainer. Aisins share challenges with the older models but come with unique problems too. High costs, limited upgrades, and parts scarcity make them less appealing. Hence, Custom Automatic Conversions (CAC) focuses on making the Allison conversion affordable and efficient.

Allison's Adaptive Advantage

The Allison stands out as it adjusts to your driving style, optimizing shifts for different habits and power levels. Notably, with CA Conversions' expertise, tap shift has been perfected for various vehicles. The Allison is unmatched in power handling, functionality, and longevity. Whether for daily use, towing, or racing, an Allison Swap is a worthwhile investment.

The Ultimate Choice: Allison 1000

If you're looking for the perfect blend of power, reliability, and seamless shifting, the Allison 1000 is the answer. CAC enables its seamless integration with the Cummins engine. While the Allison is a stellar transmission, CAC's experience shows that with the right upgrades, its performance can be further optimized.

Successful Allison Conversion with CAC

Ensuring the Allison transmission fits flawlessly in the Dodge Pickup is a task CAC has mastered. From billet adapters to cross member mounting kits, every detail is addressed. Only minor drivetrain modifications are required, and the recalibration of the engine is paramount. CAC recommends the ideal tuning for your application, ensuring optimal performance. For more information, contact us at 865-253-1133.

What's Included in the Allison Conversion Package:

  • Adapter & Flex plate
  • Transfer case adapter (4WD)
  • Properly programmed TCM and CAC's proprietary blue (5 speed) or black box (6 speed)
  • Mounting kit

Additional Options from CAC:

  • Re-manufactured Allison 5 or 6 Speed transmission with new electronics
  • Custom torque converters tailored for your conversion
  • Gear reduction 6.0L Ford style starter

3524 Garcon Point Road

Milton, FL 32583

(865) 253-1133