At left, NAG1/722.6 transmission with the filter installed.
The 722.6/NAG1 is a 5 speed transmission. Chrysler makes the NAG1 and Mercedes makes the 722.6. They are basically the same except for the torque converters. The W5A580, W5A380, and W5J400 are in the family of 722.6/NAG1 transmissions. The W5A580 is also called WA580 when people drop the first 5 from the name.
Although these transmissions may have slightly different internals, the external part, where the transmission housing connects to the stock pan, is the same. So when you are looking for a heavy duty after market transmission fluid pan, you need to first make sure you have a NAG1/722.6 transmission and then look to see how much space you have around the stock pan for a larger, heavy duty replacement pan.
PML makes three pans for the NAG1/722.6 transmission. This video gives an overview of the pans. Continue reading this page for more information.
The vehicle specifications should list the transmission. A dealer can usually tell with the VIN number. The shape of the stock transmission pan can also identify the transmission.
The stock pan has 6 retaining clips around the edge to hold it to the transmission.
Sometimes the pan is partial under the exhaust or frame cross members or covered by an underbody plate.
Measure how much space is between the stock pan and the frame, exhaust, or other parts of the vehicle. Also check the ground clearance. The transmission pan should not be the lowest thing.
It can be a hassle to check, but it's important so you know which pan will work for you. Take a ruler and a cell phone or camera to snap some pictures when you check for clearance.
PML makes three pans for the NAG1/722.6 transmission. All are heavy duty, sand cast aluminum with raised fins on the bottom. They are all larger than the stock pan. General guidelines:
This is a partial list of vehicles that usually have the NAG1/722.6 transmission. Configurations vary. Some years are transition years. Always check your vehicle to confirm transmission and clearance available.
Height and capacity differences: