ALLISON 5 OR 6 SPEED TRANSMISSION SWAP
CUSTOM AUTOMATIC CONVERSIONS, (CAC) NOW OFFERS COMPLETE KITS SO THAT AN ALLISON 5 OR 6 SPEED AUTOMATIC TRANSMISSION CAN BE INSTALLED BEHIND THE CUMMINS 12 VALVE, 24 VALVE, 5.9L AND 6.7L ENGINE.
For those of you who are not satisfied with the Dodge automatic or manual transmission behind your Cummins engine, the Allison 5 or 6 speed swap is an excellent alternative. Whether you are traversing steep terrain, towing at highway speeds, or just looking for increased reliability and power you will find that the Allison 1000 built by Custom Automatic Conversions (CAC) is superior to the factory transmissions offered by Dodge. The Allison is also a more reliable alternative to the “built” or remanufactured Dodge transmissions available in the market place today.
Dodge offered several transmission designs behind the Cummins equipped light to medium duty pickup trucks from 1989 to 2018. While many companies offer rebuilt versions of these transmissions using heavy duty upgraded parts, they DO NOT offer all of the benefits of an Allison 5 or 6 speed automatic, which can be stock or built to suit your application.
Below is a list of the Dodge offerings by year behind the Cummins motor:
1989 to 1993 2500/3500 5.9L came with the TF727 3 speed automatic transmission, then the A518 4 speed from 1991.5 to 1993 and the Getrag 5 speed manual
1994 to 1995 2500/3500 5.9L came with the A518 4 speed automatic transmission and the NV 4500 manual transmission
1996 to 2003 2500/3500 5.9L came with the 47-RE 4 speed automatic transmission and the NV 4500 or NV 5600 (01/02 HO motors) manual transmission
2003 to 2007.5 2500/3500 5.9L came with the 48-RE 4 speed automatic transmission and a NV5600 manual until 2005.5 then a G56 manual
2007.5 to 2018 2500/3500 6.7L came with the 68-RFE 6 speed automatic transmission and a G56 manual transmission
2007 to 2014 3500 Cab and Chassis came with the Aisin AS-68RC automatic transmission
2014 to 2018 3500 came optional with the 69-RC automatic transmission
Due to the nature of the Dodge transmissions, they all have very small shafts, gear sets and clutch packs, the factory Dodge transmissions require extensive modifications and expensive hard parts to even begin to compete with an Allison 1000. These parts include the hydraulic pump, clutch packs, shafts, and torque converter. These modifications are an attempt to strengthen the Dodge transmission in order to better handle the massive torque of the Cummins engine. The Allison 5 or 6 speed automatic transmission comes from the factory with large shafts, clutch packs and gear sets. This gives the Allison a direct advantage over all the Dodge transmissions and the AS 68. The AS 69-RC has similar size components to the Allison, clutch packs, shafts and gear sets, yet they are much weaker and the 69-RC does not have an ideal gear split, so the 69-RC always seems a bit “clunky” and does not handle increased power levels well. All of the Dodge torque converters are similar in size to the Allison but not as hardy, the GM torque converter in the Allison is the number one cause of failure associated with the Allison transmission in the automotive market, as it has a poor design and an extremely weak stator. All of the Dodge and GM Allison torque converters are under-designed, which means they must all be upgraded. Upgrades should include billet covers, other options are: solid components and multiple disc designs in order to be reliable and hold increased power and load.
When all costs are taken into consideration with regards to what it takes to upgrade all of the small and under-designed parts of the Dodge transmission, the upgrade to the Allison conversion can be argued to be the most cost effective solution. There are a few questions you should ask yourself when weighing the decision of whether to go with an upgraded Dodge transmission or to replace it with an Allison conversion:
Is your Cummins engine modified?
Do you tow heavy loads, especially for long distances?
Do you have over sized tires?
Does your vehicle appear to be "under stress" with the workload you are subjecting it to?
ARE YOU TIRED OF REBUILDING/REPLACING YOUR DODGE TRANSMISSION?
If you answered yes to any of these questions, you are a prime candidate for an Allison 5 or 6 speed conversion!