03 trans issues

[12vriviera]

my brothers work truck is an 03 lb7 4x4
after trans warms up it loses 4th and 5th gears and shift indicator in dash goes off...
let it cool down over night and the next morning everything was fine..
by the time he got to work 30 miles away the indicator had shut off and again lost 4th and 5th gears..
fluid level is ok and looks pretty good...

Any ideas for the allison gurus out there???

 

[JD4440]

That's a good one. Bump to the top for ya'

 

[Diesel Tech]

The NSBU and IGN Switch would be the items I would be looking at.

 

[12vriviera]

nsbu?

 

[Red_ver_2]

Neutral saftey back up sensor

 

[12vriviera]

ahh thanks... will let em know....
appreciate help guys!