Hello, this morning my truck lost all forward moving gears and reverse as well. I can stick the truck in gear running with or with out the clutch. When the clutch is pushed in while the truck is running it has a slight squill sound. The truck is 4wheel drive with 210,000miles and mostly stock. I put a #100 fuel plate 191dv (putting stock delivery valves back in) cold air and a 5" turbo back exhaust about 20,000 miles ago. I've never had any issues with the trans other then 5th gear and the stock clutch.

 

Sounds like it could be a broken input shaft. What happened when you lost your gears

 

What were you doing when it happened?