I believe the O-Rings on the power steering at the shaft on my MF 35 are leaking. What will be required too replace them?
There are no O-rings between the steering wheel shaft and the outer housing. The power steering valve is a sealed unit that slips over the steering wheel shaft. If you have oil leaking through the steering wheel shaft the power steering valve is very likely leaking. There are O-rings at the top and bottom of the valve assembly but the leak may be due to a worn valve assembly.
I am not sure the rebuild kit for the valve is still available, but replacement valve assemblies are still available from after-market suppliers. There was a change in the assembly on the MF-35 at serial number 231862. I can send you copies of the section on the power steering valve from the factory shop manual, and an exploded view of the parts, and part numbers from the parts book, but I need to know your tractor serial number to send you the correct version.