installed a hd2 kit out of another trans the one i took it out of was an 05 the one i put it in was a 2000 are the valve bodies the same because now it seems to try and take off in second gear and theres no OD the piston in the case told me to flip it and add yellow spring do you still need the blue spring on top of the piston for 4th gear.

 

No in the directions it should state to discard the factory spring if there was one there and then use the yellow one. The valve bodies are the same for the most part and this would not be your issue. With a second gear start I would look at the 1-2 accumulator piston to make sure that it is not cracked or that the seal is not cut. The no 4th gear condition sounds like a 4th gear servo issue or adjustment of the band. You might have also installed the tightly wound blue/purple spring in the wrong place and blocked the 3-4 shift valve. Go back over your install and I bet you find it. Vince


Edit make sure that the 1-2/"A" solenoid is plugged in. This solenoid is used for 1st and 4th gears.