Ok, here is the only advice I can offer you... since you said your father is able to help you, and your still a minor, I would suggest that you ask him to make copies of all the bills that you guys have paid out already, and bring copies to the two mechanics that worked on your truck. tell them that either they best get it working properly or your going to take them to small claims court. that you've paid for a service you have not received and they have BOTH allowed your truck to leave their possession not working properly. also that if it causes any other damage they will be paying for that as well.

I would also suggest that you tell them that you are MORE then willing to call the cops on both of them to help with the situation. it sounds like they are being unreasonable... and they have NOT repaired things properly. the one that gave you that transmission should have never let it leave working the way it does. do you know if it was a junkyard tranny and was it rebuilt or just thrown in?

 

Alright Cuppy.

You did check the tranny fluid to amke sure it was full correct?
Full while the engine is running and parked on flat level ground after driving 20 minutes correct?

If your tranny fluid is fine, then there is a good possibility your problem is in the governor on the tranny. The governor is ont he drivers side and inside of a half ball shaped thing. You have to pry the cover off, carefull of the rubber gasket. It will leak a little fluid once the cover is off. Reach in and pull out the governor. There are two wings that fly out as the governor goes faster. See the gear at the end of the governor, it turns the governor. Inside the governor is a valve, if this valve is sticking, you can have the problems your talking about.

You may have to disconnect the t-case linkage to get the governor out. I don't remember what year your truck is.
This is something you can do at home. If the governor is stuck. Post up and I can tell you how to clean it.

 

There is only one mechanic shop in my hometown. Everybody takes their car over there for oil change or any type of maintenance. (not me, I never have) Well, if this shop is running low on cash, they will mess with stuff in someone's car when it's getting an oil change just to be able to fix it and make money. My grandmother has a 2001 blazer. She wanted me to take it there to get the oil changed. So I checked all fluids and everything before they touched the car. An hour later they call my grandmother and say it has a bad radiator. We tell them I will be there in a minute. When I checked the coolant, there was nothing wrong with it. But when I got to the shop, they took off the radiator cap and there was mud oozing out of it. They say, "We were just checking your fluids and found this. We can fix this, but it'll cost you a radiator flush and maybe a new radiator. The radiator flush will be only....say....$150." I am not kidding. So I laugh at them and tell them I will get a second opinion. Turns out that they just poured what looked like pond water in the radiator. Just took a little bit of a flush and never had a problem with the coolant again. By the way, I have never taken any of my vehicles there for anything and never will. I only took my grandmothers blazer there because she is friends with the lady that works the cash register there. That will never happen again. So I know what it's like when a mechanic tries to screw people out of their money.