I have a 2005 Cummins with about ninety thousand miles on it. I'm currently having problems with it not shifting out of first gear. It doesn't matter if i drive it easy or hold it to the floor it wont shift untill twenty four hundred rpm. Any ideas would be greatly appreciated. It seems to shift fine through all other gears.

 

May need a new pressure solenoid switch, there have been a number of failures causing poor shifting. The switch, I believe will run you about $200.00, might be worth having some one look at it, could be that it just needs bands adjusted.

 

Governor pressure sensor and solenoid.