Iv'e been noticing in some Whirlpool parts documentation such as for the Estate ETW4450TQ0 and others, the part number reference for the drive motor states that "spring P/N 388492 must be ordered when replacing motor". This spring is the counterweight spring in the back part of the tub support. Why "must" the spring be replaced??? Actually, it just says it must be ordered, but I assume they want you to replace it. Other parts manuals for various direct drive models make no mention of this. I don't get it.