A downhole tool includes a valve assembly and a shock absorbing assembly. The valve assembly includes a valve spring operatively connected to a valve body. The shock absorbing assembly includes a spring operatively connected to a shock absorbing body having a fluid passage therethrough. The valve body is configured to selectively engage the shock absorbing body to create a fluid tight seal over the fluid passage in a first position, and to allow a fluid flow through the fluid passage in a second position. The repeated movement cycle of the selective engagement between the valve body and the shock absorbing body generates a pressure pulse or a varying pressure differential across the downhole tool. The repeated movement cycle is powered by a fluid flow. The tool may be selectively activated and deactivated.