My double kick pedal has suffered a failure in the joint that drives the left pedal. Here's a picture of the joint with the rubber boot removed.
What happens is that it's fluid on one axis but the second axis is really really tight, and doesn't move unless under extreme force. A rubber mallet will cause it to rotate, for instance but a foot, and a hand, will definitely not budge it.
What causes a joint like this to fail and is there any hope for repair on a joint this small? They don't make the part anymore and new pedals are multi-hundreds of dollars.