Sorry guy's just reading this post out of interest, I use the metal hose reel and its the corgies conkers.
If I did use the plastic type and kept getting the problems you guy's were having, I would be looking for a better solution to keep it all locked together.
Can you not go into B&Q and look in the threaded bolt section, now these threaded bolts come in about 1m lenghts, drill a couple of holes through your reels, cut these bolts to lenght, stick a couple of washers and nuts on them and they will never come apart again. I would suggest using locking nuts as all the spinning might just undo the nuts.
Hope it helps guy's?