kennyu

I just purchased a 1990 pathfinder 4x4 3.0l transmission doesn't have reverse. Will go forward with no issues. Makes noises when put in reverse. Was told that the tranny made a popping sound when reverse went out. Previous owner didn't know it was the trans due to the fact she was driving the vehicle down the highway when she heard the noise. When she got off highway and went to her destination there wasn't an issue driving it. When she came back out and started vehicle and put it in reverse it didn't move. It made like a whining noise and that's it. So my question is Do I need a new transmission ? My mechanic said it sounds like its coming from the transfer case.. Any and all help will be greatly appreciated