Hi I am one of the few that has a daully that I love. But I lost my rear end last year. So I foound a replacement and installed it my self. Truck moves but it shift late and I noticed that it rev up in the high 3000 (3800 or3900). Not what I believe is ok. I changed gears from a 4/11 to a 3/77 better gas milage. Any body got any Ideas?

 

hard to tell without knowing year of your stallion. anyways, on mine, 2000, and any newer, as far as I know, you have to change shifting points to accomodate in trannie. It's dealership. I tried, it's proprietory software to do.

 

It might be the rear end gear ratio difference, or it could be your transmission. It also could be from slamming it to the floor. Depending on the year, it might be computer controlled. If you accelerate fast, the computer will shift at a higher rpm. Just an idea.

 

Assuming it's a NBS, your PCM needs to be told about your gear change. It still thinks it's the old gears, so your speedo will show the wrong MPH, I'm assuming you got past the ABS by replacing the whole rear.(Which sends the proper signal to your OB system.) Reprogramming is in the works, whether you do it with your own(Superchips or Diablosport, for instance) or you have a mechanic with a programmer do it for you. Once your PCM has the proper gear specs, your shifts should also straighten out.