I'm at 25,000 miles. I'm pretty sure it's the original wheel bearings. They're 40 years old and I would like to take the bike on extended trips. Mostly a safety issue for my peace of mind.
Your choice. Personally I'd leave them alone. I had to renew the rearwheel bearings some time after I had foolishly washed my bike at a carwash using pressurized water. A hell of a job it was. Bearings go a looooong way.
If I put the 25,000 miles on it I'd not care as much. However, the bike sat for nearly 20 years and at that point only had about 20,000 miles on it. Since I don't know the history I don't want to be cruising at 70mph on a highway and have one of the wheels lock up on me.
It looks like basically you remove the retainers, the dust seals and then evenly distribute heat on the hub and drive the bearings out. Keep the new bearings in the freezer then using evenly distributed heat on the hub again to drive them home. Having the proper tool helps. Maybe your homemade tool made things more difficult for you?
I've done some loose ball bearing cone/race wheels on mopeds a few times. It's not glorious, but was able to do it OK.
EDIT: And yes, I did read the shop manual and took note that the retainer on the rear wheel is LEFT-HAND THREADED. A nice little trap that would cause a lot of frustration if you forget this fact!
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