Well today i let my dad drive my truck just so he could see the awesome power it has, he took it out on the road, got on it a bit, went through the gears fine, turned around at the church and on the way back he was in 3rd and it just popped outta gear, now 3rd and 4th wont work, it will go into 3rd and 4th but nothing happens, just sits there, just wanna get some ideas on what coulda happen, i did notice the last 2 weeks that the truck sometimes didnt wanna go into 3rd and 4th, guess ill call the shop tomorrow and ill get ready to spend my tax return

 

I,m not a trans guy but here is a good site.Hope it is not to bad.

New Venture NV4500 Transmission Parts

 

any help?

 

I'm thinking your clutch is getting blown. Had this happen to me but in a gasser. Third would grab after about five second the shift to fourth and it would rev up to 3500 before it would grab. had to replace the clutch, flywheel and slave cylinder.