My 15 year old Kenmore Elite HE3t was making a knocking noise during the spin cycle. So I took the lower front panel off (three screws) and taped down the safety switch on the right (Idiots, please don’t do this). When I ran the machine and got the knocking sound during the spin cycle, I pushed (with a stick of wood) on the outer tub (which does not spin), and the knock went away completely. I didn’t have to push hard. I presume that there is backlash (looseness) in one of the tub supports, or perhaps the tub is hitting the frame somewhere. Whatever, it’s been stable for a number of years now. So to fix it, I put a small spring from the top of the left front damper to an existing hole in the cabinet front. That solved the problem. The spring keeps the backlash from banging. Been working fine for a month now. I didn’t even have to move the machine to fix it.