The nut on top was a 5/8-18 nylok nut which measures 15/16". Problem is the way they designed the top of the nut well. I called 4 places and nobody had a thin wall socket. I went and got a Plumbers shower valve socket set since I remembered how thin the walls were on them, one of the sizes was 31/32 which is just slightly oversized, but it worked good for my specific application. My older brother is visiting me and provided the wrenching. We drilled out the stock 5/16" holes in the caster forks for the new 10mm bolt. It took 7 washers between the inside of the caster forks to the wheel bearing (6 of the 1/8", and 1 of the 1/16" thick . That made up the 11/16" space, as I had no one to machine a SS spacer, so I had to do the shade tree engineering method. There is only 1/4" or so of clearance between the tire and the inside of the fork. With the tire wobbling slightly, sometimes likely 1/8" of clearance.
It raised the front of the chair so much that my recline wouldn't work, so I knew that the mercury switch was likely locking it out. It was held on to a small bracket with cable ties, so I clipped the rear one and installed a new cable tie under the switch that pulled the switch up to make it functional. The other bad part of the installation is now the anti-tip wheels are making contact with the ground
I need bigger diameter tires on the rear. I read that the shocks could be adjusted with a spanned wrench which will lower or raise the back end.
Earth: The Insane Asylum of the Universe-nowhere else could things be more screwed up.
Invacare M61
Quickie S636- 3.00-4 tires, Chevy seat