Don't mean to take the thread too far off topic, but I've seen the u-joint cap issue a handful of times from various sources online (this makes 4 if I remember correctly). A guy I follow on YouTube just had the same issue and he's got this video up about it:
It was the front U-Joint that lost the cap on mine. Came off without warning, but I had read were others had the same issue we had on a Facebook Talon group.