My tilt motor is acting up, it stops working and then I give it a couple of taps with a screw driver and it starts working again. It looks like it has or should have 3 bolts, is there a 4th around the back corner of it? Looks like one of the three that I can see is broken. I tried to loosen one of the front bolts and she turns but I'm afraid it's just the bolt head getting ready to snap off as it doesn't appear to be rising out of the threads. Anyone have worldly advice on replacing the tilt motor?