I have an 08 F-150 5.4 XLT with roughly 130k on it. Twice in the last month reversing into the driveway the truck started acting up. Each time you could noticeably hear and feel the truck kinda jerking/clanking. Once was with no load and the second time was backing the boat up.

I couldn't quite tell if it was the engine or transmission. I was just quick to put it back into drive as it would make it stop. Then the other day I had the same problem for just a second while driving on the highway going up hill at about 45.

I have recently replaced the whole front knuckle on the driver side and that's about it. I'm the third owner and have had it for only about 8 months so I'm not sure of any prior work or when any of it was done.