Transmission Question
 

Hello, A few months back I bought a 2001 2500, 5.9 Cummins. 160k miles. I love the truck! Maybe I'm naïve. I bought it thinking it was a simple 3 speed automatic transmission. Every thing seems to work perfectly. The gear shift is worn and so it doesn't say anything. The other day while driving a noticed a button on the end of the gearshift. Obviously I pushed it and the O/D Off light came on. Now I know about O/D off but I was assuming my truck didn't have overdrive. It shifts through the gears smoothly, no leaks, no problems and doesn't even act like it has overdrive......help?

Yep, four speeds plus lockup converter. 4th gear is Overdrive.

Welcome to DF! Check out the 2nd Gen Ram section. :D

Any ideas you can give me on why it might not be going into 4th?