Question: how do you know when your transmission is gone?
Answer: Refusal to Switch Gears. If your vehicle refuses or struggles to change gears, you're more than likely facing a problem with your transmission system. ... 
Burning Smell. ... 
Neutral Noises. ... 
Slipping Gears. ... 
Dragging Clutch. ... 
Leaking Fluid. ... 
Check Engine Light. ... 
Grinding or Shaking.