No freaking idea. I don't abuse the truck. Never been wheeled, hardly even been off pavement. It's been a street queen (My primary DD is a Harley Softail Custom
ainkiller
. In fact, I would have to say that I noticed the first symptoms at around 6500 miles if I recall. I put on some running boards when my elderly Dad came to visit and I thought I had somehow not tightened the bolts properly, checking them again and again. It wasn't the bolts, it was the friggin X-REAS.
The rattle didn't get beyond a rattle until recently when it got really cold out.
I took the truck in for its 18 month maintenance on Dec 6th and I specifically asked them to check the X-REAS system. Of course, they tell me that the tech couldn't find anything wrong, all joints and links were tight, they said. So they asked if I wanted to go on a road test with the tech. In their defense, the problem has been somewhat intermittent, and I admit that we didn't hear anything dramatically out of the ordinary that day.
In the following week, the temps dropped to well below freezing and the rattles became clanks and bangs. I suspect the hydraulic fluid in the system had absorbed so much water in 6-7 months that it was able to freeze?
So, I decided to take it back in on Friday and tell them if they couldn't find the problem, they needed to get Toyota involved, as I was not taking the truck back in it's current condition.
Hey what do you know, after a two hour wait, they have determined that the "X system" was bad and they ordered parts which will arrive on Tuesday and be a two-day repair.
I am actually relieved that the truck will be repaired, but my confidence in Toyota quality is challenged to say the least.
Well, if the replacement XREAS ends up crapping out too, at least there's a ton of aftermarket options open to you 
