GMC Repair: 98 GMC sonoma Tranny question, gmc sonoma, cluch

Question
I have a 1998 GMC sonoma 4.0 V6 5 speed. The transmission has made no sounds, or shown a fluctuation in power/speed. I park it one night, hop in the next day to back out of the driveway and nothing. The gear shift went into the reverse position (with or without the clutch pushed in) but the truck would not move, no slipping, nothing, just wouldn't move. like as if it were in neutral still. The other five gears worked fine. then I had it in 5th gear, pushed the cluch in to downshift and it would not go into any other gear, the gearshift moves freely from fifth to neutral and into reverse, all while the truck is stuck in 5th gear. are there any suggestions as to what this could be? like i said there were no sounds, or any type of thing that lead up to this point. thank you so much :)

Answer
Hi
I would HIGHLY suspect either the shift fork or the shift shaft being your problem.
These items are VERY diffucult to replace on theis NV1500 tranny.
I would HIGHLY recommend having a professional transmission mechanic preform this work. I would recomend a rebuild OR a replacement trans.
You May also get it to a good tranny shop and have them diagnose it, also.
Good Luck
Pawl