Washer will not spin at high speed

I'm trying to diagnose a Whirlpool WFC7500VW1 with a similar problem. Sometimes the clothes are soaking wet. Didn't find any actual blockages, fill sensor and tubing all working well and it's uncommon for the control system to be a problem when things work sometimes but not others (unless there's a loose connection somewhere). In the large hose that connects to the bottom of the drum, there is a ball that is supposed to float on any water and act like a back flow valve. In my estimation, there would not be enough volume in the drain hose to fill the larger rubber hose between the drum and the pump. On this particular washer, the rubber shoulder that the ball is supposed to float up into had shrunk or something and it didn't stay in the plastic drum connection. It would easily fall down into the expanded section of the hose between the drum and the pump. After playing with it for a while, I realized that the rubber shoulder and the ball dropping entirely into the hose make it quite possible to completely block the water from getting to the pump. This might explain why sometimes a load would be fine and other times it would be way too wet. I just pulled the ball and rubber shoulder piece out entirely and we're running a few loads now to see if there's any problems with the high speed spin. So far, we're 5 for 5 with no problems. I think the back flow valve that this ball and shoulder usually provide might be important if the drain pipe is connected directly to a sewer pipe but if it's draining into a sink or an open pipe I don't think the back flow valve is that important especially since the rubber shoulder piece was too loose to provide any sort of a reliable seal anyway.

Also had a bit of a leakage problem on this washer. Turns out water would find its way out of the soap and softener dispenser around the lid. There's no seal to speak of so if the pressure is high enough to cause a splash back, some water can leak out around the lid. I put silicone around half of it where a leak was likely to occur to stop the leaking.

Check for any blockages around pump and air trap area.