autoshift will not go into any gears no error code, just flashes

My eaton fuller autoshift suddenly will not go into any gears in my driveway, just shows down arrows and R or 2(flashing) when I try to go into any gear. When i have the truck off and turn key to start position and try to shift gears i can hear the transmission shifting successfully, however once the engine is running it will not shift gears. There are no service lights or error codes being displayed. I called Eaton and they told me its either the clutch brake worn out, bent linkage, or a bad transmission. I'm skeptical, i had the truck moving in my driveway just the other day so i dont understand how the clutch brake got bad from sitting overnight. I ordered a speed (RPM) sensor ...doubt that will help. I also disconnected power to the shifter but that does not seem to have corrected the problem. Again I can hear it going into gear when the truck is not running so that must mean something...also the lack of error codes/service light.

 

Not sure a tech will come out to my house and bring computer, probably expensive. Eaton tech said its the clutch brake. A buddy is a road tech said he can swap the brake out for $300... i agree dont want to throw parts at the problem, but also not sure a tech with a computer can diagnose exact problem

 

"If it's the clutch brake you can swap it out yourself, as it should be no different than a manual transmission clutch brake."

i guess the clutch brake would need to be torched off, something i'm not comfortable doing myself.

On another note i just wasted a few hours picking up a speed sensor that did nothing to fix my problem. Also asked the nearby international dealer, tech can come out for a few hundred dollars, said either entire clutch needs to be replaced or the xy shifter, but he was just guessing. The #### thing literally was working yesterday, i just moved the truck a few feet.... What else can i try? or test. The tech told me to see if the clutch brake plate was spinning or stopped when the clutch was engaged and trying to get in gear. going to be fun to try by myself....#deathsentence

 

i was told its a gen 3 autoshift
how and where can i check my grounds? I would definitely like to do this first thing tomorrow, the mechanic also mentioned doing this but not sure where to find the grounds.
i changed the speed/rpm sensor, what next?
1.6 MILLION miles on truck
not sure what you mean by wet.
no flashing service lights
it does not fall out to gear, it just does not want to shift from Neutral into any gear.

 

anyway of testing the xy shifter and clutch brake to rule them out? Also how do i test the ground? The xy sounds like it is working when i put key in start position and select different gears