i just recently bough a 97 gmc sierra 1500 with 140k on it ive only had it for about a week. last night i was at my buddies house and we were messing around in his pasture gettin muddy. so as im going through a mud patch i start to get stuck so i let off the gas wait for the truck to stop to put it in reverse when i shift into reverse i hear a grinding noise and when i go to give it gas my tires dont spin. (im in 4h while this is going on) so i put it in neutral for a second and then back in reverse but it still wont engage it just revs up like its in neutral. my buddy gets me unstuck and i take it out of 4h thinking that might be part of the issue but when in 2h it still wont go into reverse i checked the linkage for any obvious problems and there was none that stood out so i call it a day and headed home and i notice that it revs higher than normal before it shifts into 2nd but after that it runs fine so im wondering did my transmission just s*** the bed or if its an easy fix
any help would be apreciated thanks

 

the engine is a 5.7L v8 if that helps any

 

The reverse gear may have gone out.
maybe swing by a tranny shop.