Quadcopter shaking

So my quad is shaking. I know what's causing it just need some understanding on the concept of balance. 450 quad with an extra plate mounted 1cm below the original bottom plate have attached retractable landing gear and a gimbal. Recently switched to a new carbon fiber gimbal. Different dimensions and weight of course. Since then, in flight when I activate the retracts and they get into their locked up position the quad starts shaking. Took off the gimbal and when the retracts go up, no shaking. I'm thinking the center of gravity is off now. Any suggestions for a fix? I know the props don't need to be balanced motors are all fine as well. Oh and also it's shaking on all axis.
 


Top