The life expectancy of a garbage disposal is 6-10 years depending on how much use it gets. After years of use the blades will wear down.
You Should Avoid Putting the Following Down the Drain
Uncooked Rice / Pasta
Fats and Oils
Dog Food - When wet it expends and will clog the drains
Fibrous foods - These effect the motor
Grease - Reduce the blades effectiveness
None food Substance - Such as plant clippings, sponges, twist ties, cigarette butts
Signs You Need a New One
If it won't run
Clogged or Jammed
Doesn't make any noise at all.