All gears act like neutral

[nick056]

Well I bought my first diesel yesterday. Got to drive it a whole day before it started giving me trouble. I was on the interstate in 6th gear (its a 6 speed) when there was a loud spinning noise coming from the shifter. I took it out of gear but the noise continued. I tried putting it back into gear but it didn't do anything. I tried dropping a gear and it still did nothing but now the noise had stopped. I pulled off and tried each gear and they all act as if the truck was in neutral. I checked the clutch fluid and it was fine but haven't really had an opportunity to look it over as I was on my way to work and had to get it towed back to the dealership. I feel like they will charge an arm and a leg for any repairs as it is not under any warranty because of its age and mileage (177k). Any info will help. Thanks.