Suzuki: wont shift into reverse, suzuki samuri, mechanic friend

Question
1989 suzuki samuri. While driving I smelt something burning and then it started shaking and the drive shaft came out. It was toad in and a new drive shaft was put in buy my mechanic friend. It will no longer shift into reverse. Any idea what might be wrong. I'm hoping for a simple fix, add oil, take the drive shaft out and move it to a differant position, the wrong drive shaft, or will I need a new trans.

Answer
Does the trans have enough lube?  Have you drained and refilled it, paying very close attention to how much comes out, and whether there are any metal filings/material in the oil?  But FIRST, check the shifter where it goes into the top of the trans, comparing what you see with the illustration in the shop manual.  The shifter pivot and bushing does wear out and cause shifting problems.
You can get parts at one of the businesses at the links at www.izook,com
scotty