Repairs ZD326 anti-scalp wheel shaft assembly has a blocked grease channel

Am a new owner on a 2008 Kubota ZD 326S. It has 186 hours. After purchasing the user manual from the local Kubota shop, I began adding grease to all the grease fittings. It appears this was not done for some time. The right front mower deck anti-scalp wheel mount assembly would not take any grease. I replaced the grease fitting, no joy. I removed the wheel and shaft, cleaned inside the assembly sleeve and tried to test grease flow by pumping grease without the shaft in the sleeve, no joy. I put the old fitting back on and tried again, no joy. I suspect the sleeve grease channel within the wheel mount assembly is either blocked or the sleeve has slipped within the cylinder and the original port for the grease channel is out of alignment with the grease fitting channel. Looking for an inexpensive solution that won't require a service shop visit. My plan at this point is to remove the grease fitting and using the opening as access to the exterior surface of the cylinder sleeve insert, drill a small hole through the sleeve to allow grease to fill the space between the shaft and the cylinder sleeve insert. Thoughts? Thanks in advance for any input.