Sausage

It's a Cummins not to sure about the details of truck as I am the driver not a diesel mechanic in any way I do know it's a remanded transmission it's a mack maxitourqe 18 speed everything should be tight as a tranny shop did all the work the range valve is new on top of tranny as is the shifter knob I think it's an air issue it shifts fine in morning until tranny temp reaches 150 degree or the air pressure drops below 110

I have a 07 mack cl700 dump I've been having issues shifting into low range it will grind and not move I have put over 10,000 dollars into this truck over last week or so new Tranny new shift selinoid and new shift handle and still having same issue has anyone else had this problem and if so what was the cause it's an 18 speed Tranny