Sounds like you have a bearing or bearings that are worn......a new bearing kit should fix the howling....they can be bought from several suzuki vendors.
The shifter popping out could be the shifter sheet.....you can get them from suzuki vendors in either brass or polyurethane. It could also be that the front output shaft is worn, upgraded ones can also be bought from vendors.
If you can find a known good tcase, it will probably be cheaper than buying all the above parts.