jon9314

Hi I have a 2003 f150 and almost every time I take my foot off the accelerator it sounds like I ran over a piece of sheet metal or a pop can being crushed. I can't for the life of me figure out what it is. Any thoughts would be appreciated

Red-Ford

Sounds like a bad U-joint or bad rear gears. Get under the truck while it's in park and see if you can twist the driveshaft. If you can see if it is twisting at the U-joints or if it goes all the way in the diff.

white89gt

U-joints.

Just went through this myself.

OhioLariat

I agree with the possible u-joint failure. Know, though, that while the "wiggle/rotate test can identify a problem, you can get a "false-good" indication if the u-joint is seized rather than loose. I discovered mine was broken and rusted inside only after removing the drive shaft.

jon9314

I crawled under this morning and there is no movement in the driveshaft. I will try to attach my GoPro under the truck and see if I can capture the sound.

OhioLariat

Drop the shaft. It's easy... 4 bolts, 12-point 12mm. Just remember put a mark on the flange and the mounting point before pulling it off so you get it re-installed in the same orientation. Once removed, check for free movement of the joints. If you find one is tight or seized, get yourself some *good* u-joints (Spicer, Moog, or the like), and rent/borrow a removal/install tool for your local Autozone or Advanced for the procedure. (This is SO much better than the hammer-and-cuss method.

When re-installing, tighten the bolts to 70-95 lb-ft (the most common specs I see are 77 and 83).

If that's *not* the problem, you only spent 30 minutes or so eliminating the possibility.

EDIT: On the other hand... you messed me up with the "sheet metal" comment. I was thinking vibration on decel (like *corrugated* metal), not a singular "pop." Probably not a stuck joint, but I'll leave my post for reference anyway.

Andy