I just bought a 2006 6.0 SD CC 4X4 after spending a year with a 99 v10 and it's lovely 4r100 puking habit. I added the 6.0 cooler to the 4r100 but the 1/4 million miles just wore me out thinking of the 10% + grades I have to pull my boat and family.

My questions:
Is it nornal for the 6.0 auto trans to "warm up" to the middle of the factory gauge with no load?

Is the 2006 tranny totally different than the 4r100?

 

The 6.0L Power Stroke and the 2005-2010 trucks got the 5R110W Torqshift transmission. Yes, it is a totally different beast from the 4R100, a much better transmission.

Yes, the middle of the factory gauge is about normal. The gauge is basically worthless anyway, so don't pay much attention to it. Mine rides in the middle when I an cruising with no load, doesn't matter if it is 98 degrees or -10 degrees. It stays in the middle when I am towing 9000 pounds.

 

The gauge will stay in the middle of the range when the transmission is warmer than 50°F and cooler than 230°F.