ATS Upgrades for the Allison 1000 Transmission

The Allison 1000 transmission has been designed with many good features and provides a solid foundation for us to build on to handle high HP and torque loads. The Allison 1000 transmission is a 5 speed automatic with a single disc lock-up torque converter. The five forward gears provide excellent gear selection for the 6.6L Duramax diesel. The Allison 1000 has a very low first gear ratio of 3.10:1, providing excellent acceleration when pulling heavy loads. Fourth gear is "direct drive" or one-to-one, and 5th gear is over drive with a ratio of 0.71:1.

The 1000 series Allison Transmission also has many limitations that prevent it from handling much more power than the stock 6.6 Duramax. The ATS transmission upgrade kit for the Allison 1000 is the fix for all of the design problems that limit power transfer to the rear wheels. When designing the upgrade kit we worked hard to keep the fix inexpensive and easy to install while correcting all of the faults with the 1000 series transmission.

Level 1 (up to 335 horsepower)

Eliminating 5th gear Slippage

As you increase the power of your Duramax, a cascading series of problems with the Allison 1000 begin to occur. The first problem to occur is slippage in 5th gear which causes the transmission to go into fail-safe mode. One good design function built into the control system of the Allison is the fail-safe "protection mode" to protect the transmission from damage. In the event the transmission control system senses slip it immediately throws the transmission into a neutral condition. Backing off the power when the transmission starts to slip is good for protecting the transmission, but it is not good for transferring power to the ground. Due to the limitations of the factory transmission, power out put of the Duramax is restricted severely.

We supply a new valve that replaces the factory line modifier valve in the pump with our specially designed billet valve assembly. The ATS line modifier valve corrects part of the 5th gear reduction that exists with the factory transmission, and will eliminate 5th gear slip with engines up to 335 HP.

Eliminating Torque Converter Lockup Clutch Slippage

The second major limitation of the Allison 1000 is the single disc lockup torque converter. A torque converter has two basic functions: fluid coupling and lockup The torque converter in the Allison 1000 needs major improvements in both of these areas. Once the 5th gear slippage problem is eliminated, the singe disc torque converter clutch begins to slip. The stock torque converter simply isn't designed to handle the increased power. Installing a TripleLokô torque converter easily addresses this issue. The three clutch discs on the TripleLokô will not slip even with when running very high horsepower. In repairing the 5th gear slip problem, the torque converter is removed to access the lockup valve inside the main pump located in the front of the transmission, so this is the time to replace the stock converter with the ATS TripleLokô torque converter. If your engine produces 335 HP or less, our Level 1 kit will solve both the 5th gear slippage and torque converter clutch slippage problems and your upgrade is complete.

Level 2 (over 335 horsepower)

The 5th gear fix described above only holds for engines producing 335 HP or lower. If your engine produces higher HP, a Level 2 upgrade is required, as both 3rd and 5th gear will begin to slip (1st and 2nd will follow soon after). These problems are addressed with ATS valve body modifications and the use of the ATS 1000 Commanderô.

In order to correct the 1st, 2nd, 3rd, and 5th gear slip condition above 335 HP, an auxiliary valve body must be installed, and the factory Allison valve body must be modified. the valve body must be additionally modified as follows:

  • Add the ATS auxiliary valve body that houses two additional solenoids.
  • Install the ATS 1000 Commander and wiring harness. The ATS 1000 Commander is an electronic controller that controls the Allison valve body, the engagement of the TripleLokô lockup clutches and will also control an exhaust brake.
  • Install recalibration kit into valve body

The ATS Level 2 upgrade kit builds on the Level 1 kit, and installation of the Level 1 kit is required before installing the Level 2 kit. Installation of the ATS Level 2 kit for the Allison 1000 transmission will enable you to get your Duramax power to the ground with no tranny slippage!

Features of ATS Level 2 kit for Allison 1000 Transmissions

  • Eliminates 5th gear slip
  • Eliminates torque converter lockup clutch slippage
  • Eliminates 3rd gear slip
  • Eliminates transmission from going into fail safe mode under high power conditions
  • Only raises load capacity when engine is under heavy load, 13 PSI or more manifold pressure
  • Does not use higher line pressure so it will not cause additional wear on rest of transmission
  • Converter is better matched to engine torque output
  • Cooler transmission and ATF temperatures

Due to the design of this transmission it is not possible to build it up in many small stages like we do on Ford and Dodge Transmissions. The upgrade kit will not work without installing the ATS TripleLokô torque converter because the transmission will default to fail safe mode due to torque converter clutch slip. Installation of only the ATS TripleLokô torque converter and ATS lockup valve works extremely well up to 335 HP, however, once you exceed 335 HP, 3rd and 5th gear will begin to slip and you will need the ATS Level 2 kit. The only effective fix for high horse power engines is installing both the Level 1 and Level 2 kits.

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