94 Tranny

[94jimmy]

Hello,
New to the board.Having some tranny problems.
Before the tranny seem to be making like a roaring sound.
Now when i go to put in 3rd gear in grinds as i go to put it in the gear.When i try to go into 4th gear it just keeps poping out of gear.I was told it was the syncros in the tranny and would need new tranny.Anyone Know If Thats Right?


Also anyone know which tranny i have and can i enter change it with another kind.

Truck Info:
94 GMC Jimmy 4x4 /
4.3 vortec
5-speed


Thanks in advance for any help.