It looks like the outer ring with gear teeth is seperate from the hub. How should I go about seperating them?
They were made that way as were most of the older Oliver wheel tractors, I know the wheel tractor version was not meant to be taken apart. I just checked my OC-3 parts book and they were only supplied as one piece.
The track rollers are shown as one piece and I have been heating & pressing them apart matching up the good pieces. My furnace is too small for the bullgear.
About 25 years ago I changed the hub on an OC 4. The steel gear was pressed onto a cast iron hub that was broken. We found parts at a Clark industrial parts supplier and was able to buy the hub alone. I believe that the same tracks and drive are used on some airtrack drills. At the parting line between the hub and gear were three or four large rivits. I ground off the rivit heads, heated the gear a little and drove out the hub. Drove in the new one and made new rivits from some large nails of the same size.