allison transmission

Hi Allison Man,

We have a 1996 Fleetwood Discovery Diesel Motorhome with a 6 speed Allsion Transmission. We can not get the transmission to shift into gear. We have talked to 2 different repair places and checked for codes, no codes show on the display, they both said that it is not a problem with the transmission itself. Please let me know if you have any idea's on what else it could be.

Thank you much,
allison transmission

It could possibly be broken pump drive tangs. If you have access to a pressure gauge, (I recomend a 400 pound gauge) plug into the main pressure port on the bottom of the transmission. The pressure ports are all clearly marked. If you have zero pressure then you probably have broken tangs.