You never did tell us whether or not the truck does it without the chip installed now.....

If it doesn't do it with the chip out, then it's a tuning issue.

 

im more than sure it is a tuning issue because every now and then my regular shifts come back. but lately its been staying like its on overdrive. I havent took out the chip out yet though . i ll keep you updated!

 

Taking the chip out would be the way to ensure that it is a tuning issue... It takes a few minutes..

 

A GOOD trans build will run from around 2K and go up the stronger it is. If your chip is messed up, $100-$200 is a good price. The mechanic will likely take money from you until HE figures out the problem, that could be from $100-??????. But if the chip is bad, you don't find it, the mechanic doesn't figure it out, and the tranny goes...you'll end up paying the price for all 3.

 

see I took it to the mechanic said its my overdrive switch. I can go up to 50mph but then I have to hit my overdrive button for it to shift. says I might have to replace my whole shifter because its going out already.