2016 F250 6.2 - Auto trans - 4x4, manual auto shift TC (sorry for the typo/misprint - it’s been a long day)

This started more like a rubbing noise a few months ago. It sounded like a tire rubbing on the fender liner, but it’s a stock truck and the tires don’t get anywhere near the liners when fully turned.

Now it’s become more of a vibration. It’s primarily during left turns but will happen to a lesser degree when turning right.

There was no specific moment when it started, meaning no work had been done, 4x4 hadn’t been used in the previous weeks, and no potholes, curb checks or other incidents that could have jarred the front end.

Using a chassis ear, I’ve found the source to be the trailing arm mount bolt at the rear of the left arm, where it attaches to the frame. The bolt wasn’t loose and I removed it to inspect for wear/damage but didn’t find anything on the bolt, frame/bracket or bushing. Same for the right side arm bolt/bushing. There’s no noise coming from any other area of the frame/powertrain - if I relocate the mics to different areas, it’s always quieter. See pic - the noise is loudest at the white and red arrows.




No difference if in 2 or 4 hi/low. Hubs are always in auto and I’ve verified both sides are receiving vacuum (21 in*Hg) as well as holding vacuum.

There’s no other concerns when driving straight or even on gradual road curves. It’s only when making a turn/U-turn that it’s present.

I haven’t felt anything in the steering or brake pedal when it happens. There’s no death wobble, steering pull, uneven tire wear, or anything else to indicate problems with the front end.

I’m at a loss, other than trying to replace the trailing arm bushings, but I’m hesitant to do that when I’m not finding anything to indicate they need replacement.

As always, thanks for the advice/suggestions.

 

My 13’ 6.2 crew cab does that on lefts and I just got all new steering

 

UPDATE:

2 weeks ago we installed new tires on this truck and the customer has since been in to let us know the noise is gone.

The tires were replaced just because they were due - not as an attempt to fix the noise.

The replacement tires were the same brand/tread pattern the ones that were on it so I’m not sure why that made the difference - like I said, there wasn’t any uneven tire wear or other alignment concerns.

I will update again if the noise returns.

 

Front U Joint is bad?
Chassis & drive train noise can be deceiving and travel far from the source.
Strange that new tires solved it.
Would have been nice if you could have swapped the wheel to the opposite side to see if the noise/vibe followed the wheel...or not.

 

At one point, during my initial diagnosis, I removed the front driveshaft just to see if it changed anything, but the noise/vibration was still there. While it was off, I checked the u-joint and it was moving freely and didn’t have any play.

I know what you mean about the noise traveling away from the source but that’s what the chassis ear is for. I checked for noise from both axles at first, then found it was closer to the front and continually relocated the mics until I ended up at the bushings.

We regularly service this truck so I’ll be able to keep an eye on it and see if there’s any other possible causes that are just being masked by the new tires for now.

 

At Bickford Motors I replaced all steering wear parts including steering box. The steering still had a wiggle on 50+ mph bumps. Then I read a forum. I finally got it. All front end was rebuilt (including steering box) but still had a weird wobble at 50+. After some reading I brought it to Oak Harbor Les Schwab alignment guy. They measured "natural state" castor by installing a 0° bushing -still measured +3° of castor. They then corrected camber/castor with +2° bushings. It drives like new now. My son is the senior diesel tech at Bickford (Snohomish WA) and did everything he could with the poor Ford knowledge on this. My truck drives like new again.