My machine is over 30 years old. Shaft that wigwag mounts on was rusted. It was hard to get it off. set screw was hard to break loose. wigwag was hard to break loose from the shaft. Once everything was "loose" I still had to tip the machine toward the front so I could under and hammer the wigwag off of the shaft. New wigwag was equally hard to get back on down the shaft even after I sanded the rust off of the shaft. I ended up using a wood prybar to put pressure on top of wigwag while I rotated the wigwag back and forth on the shaft.
Washer is working now. Would not spin. no special tools required just a lot of time.
my washer Kenmore 70 series 110.82374110. original wigwag p/n 35999. I bought p/n 84867. Sears said it would not work with my model. Internet said they were the same. It looks the same and is working. Sears had the best price by far.