Product review (4 stars): Complete link kit - usually need just one, so you get a spare!
What can I saw about these door balance links?  We'll when one breaks (there are two of them), your dishwasher door will seem to fall down and you will see just how heavy it is!  If you have the symptom, you probably have a broken door link.  The links come with new rollers which I didn't need since mine were still fine.  To replace a link, start by inserting at the door end then run it back and attach to the spring that hooks to the back of the frame.  Take a look at the good side (the side that didn't break) to orient the link properly and see how the spring hooks on.