I got the answer. I hope I save someone some pain. Over the last year the Synchronizer in 6th has been out but you could slide it in and keep trucking. When the clutch throw-out was replaced the person who did it put the rubber block that is at the bottom of the shifter back on the mount he put it in upside down. This caused the transmission to through fluid out the top of transmission where the shifter goes in. This caused the transmission fluid be low. When the driver hit the hill he put it in 6th and the low fluid caused 6th gear to go out. Once we got the weight off truck it drove fine to shop about 10 miles. Then they took the shifter out and seen the rubber block on wrong. Flipped the rubber block back over and put shifter back in along with 4 pints of fluid and truck was back to normal in 1,2,3,4,and 5th gear but it was to late for 6th gear. I am not sure how much damage is done in transmission but I am going to get it out and take it to someone to see how bad. I have no way of proving that was what did it but me and a few others are think that is what caused 6th gear to go out. The under side of the truck is covered with fluid and when the rubber block was put back in correctly it seemed to stop. Moral of the store..... even the smallest thing like a rubber block has to be put back correctly. I am just out a transmission repair? Thanks for your help guys.

 

it is as you thought unglued. The bearings are out in front and back and the main case is busted. Not sure if the main case can be fixed. If I can get that fixed / replaced then I can get the other parts. I checked with dealer and it is only 1500.00 for a new one heck at that price I guess I will just get two!!!! Anyway I am looking all over for a main case that I can afford and then I will order get with the guy who is actually doing all of the work on the transmission and get a good parts list from him. This has turned out to be a rough.

 

give me a call tomorrow i've got a great source for those parts or a complete reman trans