Quoted from Hi-Fi:Does your shaker motor have a threaded rod going across the top of it between the vertical brackets?? If so, keep tightening this threaded rod and check to see if the rattle lessons or goes away. I bought a shaker from Pinball Life and it had this threaded rod.
I put the shaker in test mode and kept activating it and holding anything that could possibly rattle and it eventually came down to the motor itself. I was ready to send it back to Terry and exchange it. Tightening the rod fixed my rattle issues. Don't go crazy and reef it down too tight! Just tight enough to fix your problem.
Thousand thanks, that really solved my problem and the shaker is 100% pleasure again, the ratlle was really, really annoying me.