Per your problem:
I do use dry graphite compound on the joints to keep them relatively smooth until a total rebuild. Flush them out after each day of running.
The best idea I can think of at this time is making your own mini foam covers like they have on many 1/10th ballcups. You will of course need the replacement items before this will be effective.
As per the oversite:
I noticed this happening on my m18 on just tennis courts (in that case, they wouldnt pop out, but my front end would begin to bind with all the dust between the ball and the ball hole). I thought that seemed to be a oversite since the first versions of the truck were shown.
In fact this weak area was mentioned by the community way before the truck was released:
http://www.teamxray.com/xforum/viewtopi ... 62&start=0
What a possible solution would be is metal pivot point balls. Maybe this is a planned upgrade?
Post your wants in this thread:
http://www.teamxray.com/xforum/viewtopic.php?t=2264