NV3500 transmissions 2000 Chevy Problems?

I have a Silverado, Chevy 2000 1/2 ton 4WD.Question:  Just bought this truck. Will not go into reverse. It grinds and pops out. It also makes noise going forward. Should I repair or replace. Previous owner towed 8000 lb. trailer and backed it up. It stopped working shortly after. Also says 5th is bad too. Is it bad 5/R syncro or gear? Shift fork?Answer:   From your description of all the problems it sounds like possibly excessive bearing wear is allowing shafts to move, plus damaged 5th reverse gear and synchro assembly and shift fork wear beyond the limits. The best option would be to install one of our rebuilt NV3500 transmissions in your ½ ton 4WD pickup truck.Order our part number MTGM007 your cost is $1133.33 plus $250.00 core deposit plus Shipping. This transmission will have all new bearings, gaskets, seals and syncro rings and a one year warranty.  See the other parts we can provide for the NV3500 HM290 0n our site.For more information give Scott a call toll free 888-824-2012 he can help you.