I am sure this has been asked b4, but I haven't found it. I have a 1991 stock XJ, 4.0 5 speed tranny, and I have changed my speed sensor 2 times thinking something is wrong with it, because when I install it, and tighten up the nut that holds it to the mount, it is still lose...it swivels and wiggles...is that normal ? am I wasting my money changing something that isn't bad ? or is there a problem somewhere....it is pretty simple to loosen it up, and when it gets tight, it seems like it is all the way down and secure, speedo works and everything, just have a lose sensor...thanks guys...