Ok folks I need advice. Long story short I got my dad's truck once he had his stroke. It's a 05 silverado 1500 4.8 4x4. I got the truck 4 years ago and when I got it the new transmission wasn't installed all the way yet so I finished installing it and drove about 50k miles ever since day one I got it. When I hit 55 to65 mph the truck seemed to shutter a little no loss of power once I went over or under the mph the shutter would stop. Well a week ago I was driving then all of a sudden I was going 45mph and the truck acted like it was in neutral. I pulled over tried shifting into even reverse got nothing. I turned the truck off started after 10 minutes I had gears so I took off. Truck had power and shifted amazing threw gears.then about 2 miles down the road truck started bucking and shuttering as I was driving. Then I lost all gears again. So do you think it's the torque converter since the truck had a new transmission put in and also a new used engine all with in 4 years