My son bought a 24v 2000 model 4x4 extended cab after saving up and selling his first truck. The truck drove perfectly fine when we test drove it but after buying it, it would not shift properly in drive he had to manually work it up through the gears to get it going. Then the next day it seems to be slipping after driving it 1/2 a mile. But if you kill the truck and start it back up it drives fine for another half mile and starts slipping again. Which to me says something electronic giving a faulty signal. Can anyone shed some light for me before I go bald trying to figure this thing out?

 

Is it throwing any codes? How does the trans fluid look?