Robot arm Pan Load

Hello everyone, I am building a robot arm attached to a mobile tank chassis (much like an excavator), and the problem I am having is the robot arm is trembling whenever the robot arm tries to swing left and right. What could be the problem? I suspect it must be the radial load on the base rotation (pan mechanism / horizontal swing). Any solution to counter the trembling? The servo I am using apparently is strong enough to swing the robot arm, it only trembles whenever it swings. My robot arm weighs about 500 grams + another 500 grams to grab load. Will replacing the servo with stronger servo solve the problem or do I still need bearing to counter the load no matter how strong the servo?

The entire arm seems to be supported only at the connection between the pan servo horn and the spline - normally that area needs to be reinforced.
Ex: robotshop.com/en/lynxmotion- … servo.html
You can see what other arms do for support here:
robotshop.com/en/robotic-arms.html

Nice robot by the way - would love to se a video.

I am aware that the entire arm is supported only between the pan servo and the spline servo horn, and when I test the pan mechanism, it confirms my suspicion. I need some sort of bearing to support the weight of the robot arm. Do you think Lynxmotion Base Rotate Kit can be mounted on my chassis? Because I think the casing looks too big to mount to the chassis. or maybe I dont need the round casing, just the inside parts?

Honestly don’t know - perhaps? The spline may not be compatible though - unfortunately we are not familiar with the arm nor the servos used.