Jay - According to the FAM the square steel washer is indeed for the front cab mount. From my perspective, the stack goes from bottom to top as the nut, lock washer, square washer, then any shims to get the specified "TOP OF FRAME TO BOTTOM OF FLOOR PANEL" dimension of 1.83" +.06 -.00.
The square washer prevents the lock washer from gouging into the rubber shims.
I have a FAM, just didn't find that illustration - thanks for pointing it out to me!
So, does this sound like I have it correct here?
Starting from bottom up, nut, lock washer, steel square washer, a rubber "pad washer" (sent with bolt kit), then the actual metal frame mount the bolt goes through, then another rubber "pad washer" (with kit), then any standard metal body shims to attain the correct measurement between the frame and the floor board.
