03 lb7 range shift inhibited

[03dmaxkolb]

so this started happening before i even built the tranny but has only got worse since. it come up range shift inhibited and will clunk as u go from reverse to drive. sumtimes ull have to shut it off and it will go into gear when u restart. put a new NSBU switch on rodded it around shut if off restart a few times and it was going into gear came back out 15 min later and here we go again! noticed the connectors were kinda gunky cleaned up a lil, used hair dryer on the glue plugged em bac in. took the connectors off the tcm and blew with air then re installed. could it b the pressure switch? once u get it into gear it runs fine until u shut if off and try again.

 

[BigDMax05]

Check the tcase output speed sensor(screws into top of tcase tailshaft). This is also the sensor for the abs rear wheels. Does it go shift range inhibit if you throw it into gear and try to take right off? If it does try putting it into gear and hold the truck still for a moment and then see what happens. If that's not it you may a trim valve sticking in the valve body. I have had trouble with both and both will cause shift range inhibit. It's just easier to check the speed sensor than it is to dig into the valve body. Good luck.

On a side note the more I thought about it the clunk between R and D makes me think it could be a trim valve bore boogered up. Did you have any trouble getting the new trim valves with the trans go to fit in the bores?

 

[03dmaxkolb]

ya im pretty sure its trim valve. the way it clunks. and when the trans heats up the worse it gets. i had trouble had it honed a lil and polished. im jus guna buy a new valve body im sure that will fix it.