I tried the search first but I couldnt find anything related to my problem.

My trans shifts hard under heavy acceleration from a stop during the 1st
to 2nd gear shift. Like it has a shift kit. (My truck is completely stock-no shift kit). Its been doing this for 6months+++.(I finally have the money to fix it). Under normal acceleration it shifts like nothing is wrong. Also there is no slipping it just shifts hard into 2nd gear and then shifts normally into the gears that follow like 2nd to 3rd and 3rd to 4th.

I'm basically asking for any suggestions if anyone has had or ever heard of a similar problem.
Thanks in advance

 

How long has it been since you replaced the filter? I would try that first before going to a mechanic.

 

I would say a year ago give or take month.
I read on another forum that it might be the 1-2 shift servo and spring that needs replacing. Looked easy enough to do. I think i will just drop the pan and take a look. I'll change the fluid, filter, and replace the 1-2 servo and spring and see what happens. Combined cost of those parts is cheap enough and easy to do. Hope thats all i need to do.