sonoran rock trucks

So we found what the problem was. In the deep reduction cylinder the thumb button cylinder was getting stuck. A new O-ring kit for the high and low did the trick. The truck now shift into high gear is no problem.Thanks again for the help I’m sure somebody will learn from this

ya man it was thick and looked like water got in there

I did check the transmission fluid and the oil Looks like hair gel

I purchased the truck this past October drove it home no problem the truck sat for five months and now it doesn’t want to go into high range. I have change the air filter valve in the back of the transmission. I also changed the range selector valve “slave valve” I currently do not hear any leaks in the shifter nor any of the valves. The transmission is still not going into high range. It was running perfectly fine before I parked it five months ago. Any suggestions would be greatly appreciated thanks