Wow, some great info here! I have a Country Coach Lexa that has the same shower, and same issues, I hope it's ok if a non (Yet!) Newell owner takes advantage of all your expertise!
Before I snap the joints by trying to push up my sagging middle bar, I can't quite tell if the joints have an adjustment screw - in CKNuth's great pictures in Post #52, I see a Phillips head screw in the joints at
http://newellgurus.com/attachment.php?aid=8154 (image 10 of 14), that I think might be accessible through the plug in the center round piece. Does that adjust the 'tension' of the center piece at all, or is it a fixed location?
From the pics, it looks like that Phillips screw might replace the Allen screw in older/original versions, is that the adjuster that some have tried (to varying success)? Such as in the comment by bikestuff in Post #7 "There are adjustment screws at the top of door inside the little round thingy. (Look at Tom's document at top of thread for instructions)." and I'm not quite sure which screw and round thingy is being referred to, is it the Allen screw (that might now be Phillips on replacement joints)?
I figured I'd try this before trying Chester Stone's 2x4 and jack in post #8, given the # of broken joints I've seen on this thread :-) Chester, did you hang the 2x4 below the center piece from the two ends, and jack the middle up using the two ends? (ie. ratchet straps at the ends, a little slack at first, then tightening?) I'm trying to picture exactly how you did this.
Cheers!
-Jim