here is the problem, there are three little balls that normally rest in slots in a cup, thats how the joint works, these balls are on the outer axel side held by a spider and are spring loaded outwards against the joint slots, and if you pull the axel out too far, they pop out. you can feel them under the rubber boot. the fix is really really easy, just push them in and push in the axel, I will now include a picture to demonstrate. someone save this pic because my photobucket might not always be around and I'd like this to stay
top two pictures are the axel and joint, one looking cross section from the side and one from looking straight at it (the right side picture, looks like if there were no dust boot, conceptually at least). they are in the happy normal operational state. the bottom two show where the axel has popped out and the axel wont go back in. just press the balls in as shown, and it slip right in. took me 5 seconds once I figured this out.



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