I have an issue I cant quite figure out. My 2001 F250 ext long bed Lariat is 1/2-3/4" lower on the drivers side.

History: Bought new in Detroit area, driven to Denver area, about 7000 ft elevation, been there until this year. Not used much, 73k miles. Sat until recently, outside with the passenger side facing the sun, front sitting higher than the rear, parked on sand. Driven occasionally by extended family. It was poked slightly in the driver rear (or they backed into something). Pushed the bumper into the box corner. Very slight wow in the bumper bracket. I fixed the sheet metal and replaced the bumper. It has original everything, shocks, springs brakes....everything.

I notice when driving lately (the weather is warming up) that there are some noises when turning. Like body mounts are bad...but I looked at everything underneath and its all like new and nothing loose or decayed.

Could the frame be tweaked or bent from that slight hit in the rear? Or did the sun do something funky to the springs? Help me out here. Dont want to just start throwing money at it but want to figure it out.

The pic is that box damage before I fixed it. I will add a pic of the bumper bracket later. The bumper was pitched as it was junk.

 

Sat with a full gas tank alot. Most trucks lean a little to the drivers side when tank is full

 

Common problem on a super duty, even the new 2021'S! Weight from the gas tanks makes the drivers leaf spring sag and you get that dreaded lean. Ford has a TSB about this and they sell different leaf shims to compensate for how bad the lean is

Your thud sound is most likely front sway bar links are shot. Again another common problem on the leaf spring font super duty trucks. Remove sway bar to verify it's the problem, order poky bushing kit and install them. Then never worry about them again

 

If it sounds like a duck, your body mounts could very well be quacking. Or is it cracking?

Ford's Special Service Message 13940 addresses an issue with the rear cab mounts on crew cabs built before February 25, 2000, but your truck appears to be an extended cab 2001 model, so that SSM wouldn't be applicable.

Or would it be?

I have discovered that the cab sheet metal tail flange at the bottom of the back wall of the cab, inline with the rear cab mount, on the driver's side, can crack.

It is as if the back wall sheet metal tail flange resolved the twisting stress by cracking apart, where there was not enough give in the cab insulators that could resolve the stress or absorb the twisting difference between the frame and the cab.

To find the crack is very difficult, but go to the rear cab mount, and draw an imaginary line from that cab mount straight back, parallel to the frame, but outboard of the frame, similar to the manner in which the cab mount is outboard of the frame.

Three pieces of sheet metal are overlapped and spot welded together in a sandwich. The rearmost, outer most sheet is the exterior sheet of the cab wall, which drops lower than the other sheet metal elements, and forms what I call a tail flange hanging down. You might find a vertical hairline crack in that tail flange, going vertically, for up to an inch (the longest I have seen).

When sheet metal cracks, it makes a snap crackle and pop.

 

I looked at oasis and there were no tsb's on my Vin. I guess it didn't occur to me that the fuel tank would make that difference on one of these. A bit surprising but makes sense. Not sure if I want to do the work but I guess I could swap the springs side to side. It would be easy, it's like new under there.

On the creaking noise, I'll look at the cab corner for that crack. I checked all the bushings inc the sway bar and everything is solid. I'm still going to remove it to see if it makes a difference.

I have a rubbing nose in the column too. May be clock spring, not sure yet. Will pull the wheel and have a look.

Remember, this thing only has 73k on it. I don't think anything is worn out yet.

Thanks for the replies!