Transmission shifting too soon

[roamer5]

I have a 2007 American Tradition with a Cummins 400, MH3000 Allison, with about 65,000 miles. The problem is: the coach shifts from 1st to 2nd too soon, (before the turbo has a chance to kick in) and then shifts from 2nd to 3rd too soon as well, so the takeoffs are very slow. Once it's in 3rd and from there on up, it's fine. I've heard there's an easy way to program the transmission, but have no idea how. Any ideas? Don

[BFlinn181]

I'd note at what RPM the engine is up-shifting. The transmission has a limited ability to 'learn' your driving habits. Have you tried really flooring it on starting from a stop? Seen any changes in shifting points? While programming the transmission is easy, that's only if you have the Allison program and ability to connect the transmission to a computer. Check with an Allison shop to see if your transmission needs reprogramming.

[Pigman1]

Do you have the MODE button depressed and is the transmission in economy mode? On mine when I set economy mode the acceleration from a stop is quite poor.

[BFlinn181]

I agree with Pigman1, make sure the display doesn't show an 'E' for economy. I'd think that the trans should reset each time it's shut off, but maybe not. Try pushing the 'Mode' button while driving and see if you can shift from regular to economy mode.