Clearly, Russell is guessing.
Again, if the shaft is bent, I don't think there is any alternative to replacing it. Of course, the center spindle is driven by the gearbox. So, that means disassembling the gearbox.
*If* that shaft is bent, that was a mighty immovable rock! Are you sure the "wobble" is not just a bent blade? That would seem more likely...
When I rebuilt my RC54, to remove the gearbox, I simply removed the snap ring (aka circlip, C-ring) under the blade that retains the blade boss to the shaft. When I lifted the gearbox, the shaft slid out of the spindle bearing. That was surprising, because on the other spindles, the bearings are pressed on.
The spindle bearings in all three housings are held in place by large internal snap rings.
Removing the pulleys from the shafts wasn't easy either, because the shafts are not tapered at that point. You'll need a gear puller. [You have to remove the center pulley to replace the lower seal in the gearbox.] I was surprised to see that the recommendation in the Operator's Manual for the RC54 is to replace the gear box seals every 2 years of use! Probably wise, because a gearbox doesn't last long without gear oil in it!
I thought about taking that snap ring off the shaft that is just under the top cover of the gearbox. When I did that, the gearbox did not want to easily slip off the shaft, and I thought better of it, considering that it might be difficult to line up the two bearings and two gears when replacing it. Especially since I didn't need to rebuild the gearbox itself.
-Paul
PS, I sent wayne the Parts List for RC54, thinking that might help him get his head wrapped around the scope of the job.
