I contacted some of my buddies concerning the mount you mentioned. You may have a flawed mount. I was told that sometimes the milling of the parts are not up to tolerences specified by the maker. Though they should have tested it before it was shipped to be sold, a few crappy ones slip through. Also consider that the 8" SCT may be too heavy for the mount, but I don't think so. Check the "hinges" or bearings with no wieght and see how much slop you have. See if there is a way to tightened the bearings. Sometimes a bearing race will be too big or too loose. The pivot points have been known to be loose on all kinds of mounts and all is needed is to tighten those points. Good luck..and I hope you didn't get a crappy. Also I would hold off on drive system untill you work out the bugs...