tranny problem

[wheelin1978]

hey guys I've got a few problems to ask about. I have a 99 f-250 w/7.3 and automatic trans. K&n airfilter, chip(100hp),4 inch exhaust, 35 inch mudders. I 'm on way to the dealer to buy trade this truch in on a new one and about half way there the tranny decides not to shift out of first. this happened without any warning no previous problems? I was told by someone to check the fuses, but i trust you guys opinion more than his so please help and thanks again for being here

[Ranch96]

My brother's dodge did the same thing and he cleaned the air filter and that at least let him shift it manually.
I'm sure someone else with more info will be along soon.

[ruffneck_davis]

im havin the same problem please reply what was wrong. KRIS

[CSIPSD]

Could be the VSS (vehicle speed sensor) on the rear pumpkin... Could be a dead tranny too... Just put a new tranny in the wifes X... Would shift to first and second but no farther...