Typically, garbage disposals usually last anywhere from 5 to 10 years. Well manufactured units may even last longer than that. If you’re really looking to save some money, you can always disconnect your unit, dissect it, seal the crack and reattach it. However, this is just a temporary fix. If you have the money, it’s best just to invest in a new unit.
Another common cause for a leaking garbage disposal is the disposal flange. A leak at the very most upper area of the garbage disposal could be the garbage disposal flange which goes through the sink. A garbage disposal flange should be sealed with Plumber’s putty and then tightened from underneath the sink. If this is not tight enough or if it has managed to come loose (which can happen) then the garbage disposal will have to be taken down so the flange can be resealed and then the garbage disposal can be rehung.