Here are pictures of the Allison Deep Pan install as well as part numbers

Here are the Parts Needed Part Name Allison Part Number Deep Pan 29536522 Internal Filter 29537966 Pan Gasket (reusable) 29536526 External Spin On Filter 29539579

The deep pan (actually called the standard pan by Allison) adds an additional 3.2 quarts to the capacity of the transmission. This brings the total number of quarts up to 15.9 for the total system. This additional amount of fluid, in theory, will help keep the transmission running cooler due to the fact there is more fluid to carry the heat away from the transmission. Allison also states that by using their Transynd synthetic transmission fluid, drains of up to 150,000 miles are allowed due to the formulation. At nearly $30 a gallon it better!! I purchased 4 gallons of Transynd fluid as I intended to "flush" the regular DEX III transmission fluid out to have as close to 100% synthetic fluid in my transmission as possible.

This project was very simple and took about an hour or so to complete. First, I raised the truck and supported it on jackstands to give extra working room underneath. I then drained the transmission fluid by taking out the drain plug. Once drained, you can then remove the pan bolts and remove the pan from the transmission. Use care with the gasket as it is reusable, there is no need to buy a new one unless it gets damaged. Then, the internal filter can be removed. Make sure the seal comes out with the filter when you pull it out. You can then install the new internal filter back into the transmission. Remove the pan magnet, clean it and place it in the new pan. Install the new pan with the old gasket and torque the pan bolts to 20 ft-lbs. At this point you can then change the external transmission filter. Please note, the magnet that is installed on the old filter must be cleaned and placed on the new filter.

Now it is time to add your choice of transmission fluid. I chose to overfill the transmission by 4 qts because there are about 4 qts left in the system (torque converter, cooler and lines) that need to be flushed out. I removed the "from cooler transmission line" from the transmission and placed a 5/8" hose on the end of the line and ran it into an empty milk jug. In case you haven't seen the Jiffy-Tite style connectors used on the cooler lines before: Slide back the plastic cover over the c-clip-shaped spring, then use a small screwdriver to pop the spring out of its groove. KEEP A FINGER ON THE SPRING AS YOU DO THIS, because those springs just love to go flying off into some dark hole where you'll never find it. Once the spring is out, just pull and wiggle on the line until it comes out of the fitting. As soon as you have the line out you can put the spring back into its groove so you don't lose it - the line will snap right back into place when you're done, even with the spring there. Now you can start the truck and run it until the milk jug is full (generally having a second person around to help is a good idea). Once done, you can reconnect the transmission line, restart the truck and check the cold fluid level. Add any fluid necessary to fill it up to the cold level and then take the truck around the block to warm it up to operating temperature (160-190 degrees) to make your final fluid adjustments.

Here are some pictures I took during the process: