The problem with the stock Allison 1000 5- and 6-speed pan is simple: the drain plug isn’t at the bottom. The sheet metal is pushed up, the wellnut sticks into the fluid volume, and that leaves a layer of old fluid across the pan after you pull the plug. In this case, it’s nearly two quarts still sitting there. If you want that dirty fluid out, you have to drop the pan. Our Banks Ram-Air Transmission Pan fixes the service problem by putting a magnetic drain plug at the true low point, so you get a more complete drain without pulling the pan. It also adds Ram-Air cooling with Flow-Thru Fins®, so the pan does more than hold fluid—it helps reject heat and makes routine service cleaner and easier.
The segment focuses on a problem with the stock transmission pan: a significant amount of old fluid remains trapped even after draining. The cause is identified as a protruding weld nut inside the pan. Because it extends upward into the fluid volume, it prevents the pan from emptying completely through the drain.
Some fluid remaining elsewhere in the transmission, including the torque converter, is expected. The issue demonstrated here is specifically how much fluid remains trapped inside the pan itself after a normal drain.
To quantify the problem, the remaining fluid from the removed pan is poured into a graduated cylinder. The measurement passes 1,000 mL, roughly one quart, continues beyond a quart and a half, and ultimately reaches approximately 1,850 mL.
That is nearly 2 quarts of transmission fluid left in the pan after it had already been drained. The demonstration shows that a substantial amount of old ATF remains unless the stock pan is physically removed.
With the pan removed, the reason becomes clear. The sheet metal around the drain is raised by approximately half an inch, while the internal nut adds roughly another half inch. Together, those features create approximately an inch of trapped fluid depth at the bottom of the pan.
Because the effective drain point sits above the lowest portion of the pan, a layer of old ATF remains after draining. Removing that residual fluid therefore requires taking the stock pan off the transmission.
The Banks Ram-Air Transmission Pan for Allison 5-, 6-, and 10-speed transmissions addresses the problem by placing its magnetic drain plug at the absolute lowest point of the pan. This allows the fluid in the pan to drain more completely without requiring pan removal.
The Banks design also incorporates its Ram-Air cooling system and Flow-Thru Fins® as part of the pan's thermal-management strategy.
By eliminating the raised drain geometry of the stock pan, the Banks design allows more of the old transmission fluid to be removed during routine service. The magnetic drain plug is positioned at the lowest point while also providing a way to capture ferrous debris circulating in the fluid.
Beyond serviceability, the pan incorporates Banks' Ram-Air cooling concept and Flow-Thru Fins®, combining improved drainage with features designed to increase heat rejection.
The demonstration shows approximately 1,850 mL, nearly 2 quarts, of transmission fluid remaining in the stock pan after draining. Banks attributes this trapped fluid to the raised sheet-metal geometry and protruding internal drain nut, which position the effective drain point above the bottom of the pan.
The Banks Ram-Air Transmission Pan addresses that limitation with a magnetic drain plug positioned at the lowest point, allowing a more complete pan drain while also incorporating Ram-Air cooling and Flow-Thru Fins® for improved thermal management.
