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I have ordered all the ball joints and bushings with the exception of the K6215
I am getting discontinued, unavailable, no longer available, notify me when.,...
suggestions?"
The original ball joints were riveted in place, and according to the manual, (GMC Motorhome Maintenance Manual X-7725) on page 3A-17 under "Ball Joint Checks", a pry bar is used to check for play. The "reading must not exceed .125". That is 1/8th inch. Unfortunately most alignment shops will check for play and to them any play at all is unacceptable, so they charge you for, and replace ball joints that don't need replacement.
IF the joint is .125" or less, you are best to leave it in place and make sure you grease it regularly. Could last the rest of your life without worry. JWIT