I have a 2016 F-150 XLT 4x4 with about 26k on it. At around 3k it developed a clunk in the drive train. I'm not a mechanic so I'll do my best to describe the situation. It happens at speeds above 30 (4-6 gear). When I let off the gas during normal city driving and get back on it there is a clunk sound towards the rear of the truck. It happens about 75% of the time during normal driving. I have taken the truck to the dealership (Crossroads Ford of Cary, NC) at least 6 times, likely more, trying to get this issue resolved.

Initial visits focused on lubing up everything to resolve it, no luck. The last visit had them replacing a component of the torque converter and they kept the vehicle for over a week to better "troubleshoot" the issue. We also tried the service department of a different dealership in the same dealership family (Crossroads of ***uay-Varina, NC) with no luck. I'm want to resolve this issue during the warranty period and I don't want to let this issue go. Crossroads has told us they can't fix it, or don't know how to. We feel like we're at our wits end. We love the truck but don't want this issue to become a bigger problem down the road. Part of me wants to trade the truck in but I can't afford that as I'm still upside down in the loan and will be for at least 1.5 years.

Has anyone experienced anything similar? If so, did you get it resolved?

 

Mine does the same but at low speeds. For me its just the natural play in the u joints, splines, and ring and pinion of the diff as you step on the gas. I wouldn't stress about it unless it sounds like a rabid 4 year old with a gong.

 

Common issue on at least the last 4 generations of F150s. There are a ton of videos on YouTube where guys have mounted cameras under the truck to figure it out. Commonly the noise is the time it's the slip yoke on the driveshaft that gets dry and makes a clunk at low speeds. The transmission cross member is also forward on the trans body. This leaves more trans and transfer case able to move around under drive line stresses. This movement in addition to the axle going up/down and the motor/trans mounts flexing cause the driveshaft to absorb all the the motion. When this happens it can make a popping sound. I wouldn't worry about it too much. I certainly wouldn't take a big financial hit because of it.

 

I have a 15 and have sort of same issue. Between 4th and 6th driving when I let off gas and accelerate again I get a metal rub/vibration in the trans area. This was at 39k. The dealer rebuilt the trans with upgraded clutch packs per TSB. All was good till 45k and issue is back. Same sound and I also lose power, as I let off gas and reapply Feels like trans goes neutral for a quick sec sound occurs and truck moves again. That's one issue I'm still battling the IWE, vacuum issue with the front hubs. Truck goes to a different dealer this coming Thursday I'll leave an update.

 

I don't suppose they would get a factory rep involved?

 

Pretty common all the way back to the 9" rear ends of the sixties. It really depends on how much play is in the rear end design. Some rear ends have more play than others. I don't think I have owned an F150 that the rear end does not clunk now and then. Some are louder than others. Six trucks and counting.

 

It's most likely the driveshaft slip yoke where it connects to the rear diff. The factory grease sticks when the slip yoke moves in and out of the diff. The issue can be resolved by removing the factory grease from the slip yoke and applying teflon grease in its place. I had to do this on my old 2011 crew cab I used to have. Since the dealer wouldn't do it under warranty, I took it to a local guy who specializes in Fords and he did it for 50 bucks. If I were you, I'd give this a shot (it's worth $50 just to be done with it). Seems to be an issue more prevalent with crew cabs, because my extended cab has never done it. My truck has a one piece driveshaft, and I think the crew cabs have a two piece. I believe it has something to do with that. Teflon grease should do the trick.