A couple of things to try. I always believe a lot in cause and effect downswing faults. You may be over active in the lower body becuase you over rotate and/or slide your lower body too much in the backswing meaning it has to very active in the downswing to get back to the ball

Try and focus on keeping the lower body really quiet on the backswing. In fact try and think about keeping the hips as still as possible whilst turning the shoulders (Mcleans X-Factor) and also try and stay centered over the ball. In other words a really still lower body. The less moving parts on the backswing the better

You *may* find this then slows down your lower body lurch on the downswing because from that position all you have to do (all you can do) is rotate, else youd fall over !