I've got a 4x4 2016 XLT with the 3.5EB engine, about 22K miles.. About a week ago I noticed the truck would occasionally shudder when accelerating, almost like I was hitting a rumble-strip. This would only happen when I was in 5th or 6th gear and accelerating just enough to unlock to torque converter, but not enough to downshift.

Then yesterday I started accelerating up a tight onramp and loud banging from the front end (sounded like from the front passenger tire area, but hard to be sure). Stopped immediately when I let of the gas, resumed immediately when I started accerating again. Was in 5th gear at the time, unsure of speed (maybe 40-50 mph)?

My question is: Does this sound like an IWE or front hub problem? If not, what do you guys think it is? I'm trying to get an appointment at the dealer to get it looked at, but I want to at least be able to point them in the right direction.

 

More datapoints after troubleshooting yesterday:

1. Disconnected the vacuum lines from the IWE solenoid and drove (as I understand it, this engages the hubs, but not the transfer case). Behavior was unchanged (stuttering/shuddering in 5th or 6th)
2. With engine running verified there is vacuum at the IWE solenoid.

#1 leads me to believe that this isn't a hub issue. At this point I have no idea what is going on. I've got an appointment at the dealership tomorrow, we'll see what they say.

 

Let us know what happens!

 

Just heard from the dealership. All they would say on the phone is that a "check valve went bad," and that was the cause of all my problems.

 

Just wanted to give a quick update: Problem is still not fixed. Dealership has replaced the check-valve and both front IWEs. Truck still exhibits the issue (specifically vibrating while accelerating in 5th and 6th). To be fair, the truck doesn't bang or bind up while taking an off-ramp anymore, so I think they definitely fixed something, just not everything yet. I'm trying to get the truck back in for service.

Has anyone dealt with this before? I thought for sure it would be an IWE issue, but with two new IWEs and new check valves I'm at a loss.

 

Quick update: Dealership finally diagnosed it as a bad torque converter. Ended up pulling the transmission and replacing the converter. Runs fine now.

I was unaware of torque converter issues on this truck. Is this a common thing, or did I just have some bad luck from the factory?

 

Wanted to post another update:

Problem ended up recurring a couple of weeks after the new torque converter was installed. Brought it back to the dealership and the found a small coolant leak in the transmission cooler, which apparently allowed a little coolant to mix with the transmission fluid. They ended up replacing the radiator/transmission cooler and overhauling the transmission to deal with the coolant damage.

Got my truck back a week ago, and everything seems to be running correctly again. I'm crossing my fingers that this is actually the solution this time. . .

 

Hm, My truck does something similar, I figured the torque converter was a lock-up unit and what I was hearing/feeling was the clutches engaging/disengaging when I was going on and off the throttle. The noise isn't super loud, and it only jolts the truck if I abruptly let off then stab the throttle (like if someone cuts me off then I have to get around them)