Thanks for the replies. The pump feels like it is sticking in one spot as you rotate the shaft. The tractor has done a lot of sitting in the past so I'm trying to determine if it has trash that has gotten down around the shaft in an area that I can't see or if it is damaged. The reason the engine is apart is it spun a connector bearing. So I am also trying to make sure the oil circuit is good and clean and everything is operating like it is supposed to before I close the engine block back up.
It sounds like some special tooling might be needed to get that apart then. If that is the case, would I be better off just to replace the pump? I'm just hesitant about putting a questionable pump back in. I'm still not 100% sure of what caused the bearing to spin so I was trying to ensure the oil circuit is working correctly and within spec. My plan was to measure the spacing in the gears and all the other checks it recommend in the manual but if it requires the purchase of a lot of tooling I may consider just getting a new pump. Talking to some diesel mechanics who work on frieght trucks, they most of time go ahead and replace the oil pump when a bearing spins to make sure a weak pump was not the root cause. But some of the machines they are working with are not near as forgiving when things are not at optimal spec.
Thanks for the replies.