First, only twice has someone worked on my 2008 Superduty besides me.
1 - Warranty alternator, right side of truck - This Ford dealer is now out of business
2 - Warranty radiator and centerlink - This Ford dealer, a different one, is also out of business
Second, I have only Snap-on tools
I would turn left, if going a decent clip I would hear a snap. Very repeatable, but didn't do it when I was going slow
Original ball joints, original brakes, original wheel bearings, aftermarket shocks that I installed. I was sure that I had a sticky ball joint, or worn sway bar end links, not unusual any time after 60-80K on a Ford 4x4.
Couldn't get it to do it standing still, couldn't get it to do it going slow.
Finally today I stripped it down, checked wheel bearing on that side, disconnected sway bar, took brakes off, worked everything hard.
Even decided to drill and tap ball joints for grease fittings (I would have replaced the ball joints if the snapping changed, I figured if they were bad and I pumped grease in, something would change and at least give me a clue)
Bounced the 8200 lb truck up and down, jiggled everything, pried everywhere, finally when I dropped it off the jack, purposely, I heard a snap/jiggle noise from the back of the fender.
Slapped the fender a few times, and there was my noise
Two 3/8 Craftsman short extensions and a 15mm Craftsman shallow socket. Sounds like tools needed for an alternator R&R!
Got to love it that the truck wasn't broken, but I can't believe a mechanic would leave their tools in a vehicle if they couldn't find them
Not sure where they initially landed, because it didn't make any noises for at least a year, which compounded my troubleshooting issue. In the end, they worked their way down and made a good KER-SNAP now when the body flexed a little
Happy ending for me I guess, but sure took a while to find. Goes to show, don't talk yourself into a solution!