I drive a 2006, 2500, 5.9 Cummins, automatic transmission. Since I have had the truck, when I check my auto transmission fluid, the fluid is almost frothy is the best way to describe in that it has a lot of air mixed with it. We have changed the fluid and filter with no difference. Is this normal for this setup?

Roper

 

Sounds like the fluid level is too high.

 

Not to long ago I pulled all the fluids out of the truck, front to back, and replaced them all with Amzoil synthetic and actually increased the MPG by 1.5. The fluid is a little above the full mark on the dipstick but I thought that might be due to the air mixed with the fluid.

Thanks

 

The reason its got air in it is because the level is to high.
the trans fluid has to be hot to check it if you check it when its cold. It will be lower on the stick. when oil heats up it expands causing it to be over full.

How are you checking it?

 

Check it in neutral at idle, never had your problem with my 06.