Jumps off road when hit a bump

Hello, this is obviously a safety issue! A wheel alignment check - including checking the rear axle - should be performed. A suspension that has the rear wheels in a "dog tracking" kind of position can cause this kind of harmonic disruption over bumps. That said, other broken, frozen or worn suspension components can contribute to this kind of issue and must be closely inspected. https://repairpal.com/repair-shops/toyota-repair-and-service-in-jackson-minnesota