I cleaned and repacked mine at 15,000 miles. Now at 21,000 still no problems. However, in thinking about it, an 80% solution for about 10% work effort and 50% of the cost, might be:
1) replace the upper bearing and race
2) Leaving it in place, "wipe only" and repack the lower bearing and race. Then rotate the race if possible.
All this can be done without loosing the lower fork clamps, removing the forks, wheels, etc., etc. and should take one half to one hour. If it does not solve the problem, you have lost no money, and only one hour of your own time, and you might have learned something also.
Good luck,
