Anyone have experience with this issue & what was done?
Does anyone have guidance on replacing the 2 shaft bearings and seal? Or a service manual?

Note that there was also a high pitch noise when the pump was running. I removed the pump and found the rotor would chatter when spun by hand. The chatter went away when I lubed the outer bushing next to the fan blade end.

The techs that answer are pretty knowlegeable about American appliances.

After obtaining the service manual and evaluating all the listed potential causes, I started disassembly and checking per the list. After I removed the magnetic rotor from the bottom of the outer tub, I hand rotated the shaft to see if the bearings seemed rough or binding. To my surprize, I saw the shaft retaining nut move too! The nut was loose and probably only kept from coming off by the mag rotor. The shaft rotated with both a gritty feel and a repeated binding effect. When I removed the shaft, I found that the tubular bearing spacer was very loose inside and after removal, appeared to have been wobbling to cause the repeated binding effect. The loose shaft retainer nut was probably the root cause of my problem: this allowed the bearing stackup to separate enough for the spacer to start wobbling/hanging, driving the bearings further apart. At some point the vibration probably caused some minor seal leakage, because I did find the upper or inner bearing was rusty on top and gritty when turned, even though it is a "sealed" bearing. It definitely was damaged and failing. I suspect the horendous level of noise had actually been generated by the loose spacer wobbling around. I replaced both bearings and the seal, and made sure the spacer was tight between the bearings (to comfirm not worn when wobbling), and that the retainer nut was good and tight.

As a side note: The service manual called for a bearing replacement tool kit, which turned out to be prohibitively expensive. Having experience with changing bearings in various gearboxes, I came up with my own tool pkg, by purchasing a threaded rod, 3 nuts and assorted washers of necessary diameters. Since I knew I had to replace the bearings(comes in a kit), I just used a non metal rod to tap out the outer bearing first, but one has to be careful not to tap too hard due to potential to damage the housing. The rest of the process was performed with the threaded rod, nuts & washers.

Changing The Bearings On a Fisher & Paykel GW512 Excellence
Topload Washing Machine

I used the Fisher & Paykel Parts Manual # 517751 as a reference.

Remove washing machine to a safe area and lay on its side.

Removal Procedure
1. Remove the connectors from the pump.
2. Remove pump and loosen pump hose clamp.
3. Remove pump bracket, hose and plastic shield.
4. Undo rotor nut on bottom of the smart drive assembly.
5. Remove rotor.
6. Undo and remove the 4 bolts holding the stator clamp and remove the clamp.
7. Remove the stator connectors noting the position of the connectors. Remove the stator and pump cables from the cable clamps and undo the 2 screws holding the hose bracket. (I taped the cables to the hose assembly to keep them out of the way).
8. Stand the machine upright and remove the 2 screws holding the top and open the cover backwards on its hinges.
9. Remove pressure sensor hose clamp and hose from rear of the outer bowl.
10. Unclip and remove the top neck ring assembly complete with spring out of the way.
11. Undo and remove the agitator. Remove the 3 screws holding the spline kit assembly and remove. Remove the inner bowl (I had to use a little bit of force because of the scum that had built up on the shaft)
12. Lift the outer bowl assembly and unclip from the 4 suspension assemblies. When all are unclipped remove the outer bowl from the chassis.
13. Undo the bottom bearing nut (I had to use a pair of multigrips on the shaft and a 12ʺ shifter)
14. Remove the drive shaft through the top of the bowl (I had to give it a bit of help with a block of hard wood)
15. Remove the lip seal (I had to cut the seal into sections and use multigrips to pull it gently out from the top)
Note: The bearings are housed in a cast metal insert in bottom of the plastic outer bowl.
16. Knock the bottom bearing out from the top (I used a hard wood rod)
17. Remove the bearing spacer and then knock the upper bearing from the bottom through to the top (I used the wooden rod)
18. Clean the area thoroughly (I put it under the hose and gave it a good wash out)

Reassembly

19. Lightly grease the metal insert where the bearings sit. Insert the top bearing and seat.
20. Insert the lip seal and seat properly (I used the wood and seated it level with the top of the bowl)
21. Lightly grease the drive shaft and insert from the top noting there is a lip on the shaft that sits onto the top of the top bearing (the long threaded end is the bottom of the shaft)
22. Insert the bearing spacer and bottom bearing over the shaft and seat (I used the wooden rod again to seat it)
23. Replace the drive shaft nut and tighten (I used the multigrips on the shaft to hold it while I tightened the nut)
24. Reassemble the washing machine in reverse order from step 12.

I am a bit surprised that there was not a tag washer to lock the shaft nut in place below the bottom bearing. I used some non hardening liquid called 'Loctite" and hope it will do the job.

Not sure what the model would be in the US but it was a F & P Pride 5.5 in Australia