I am about to have the bearings replaced in my 2016 lariat 8.8 front diff (again). Truck has 34K on the odometer.

I'm curious if the most recent repair (by a Ford dealer in Jan 2020) was just done incorrectly, or if there is something lurking to cause this again. With this failure i measured .009" of thrust play in the pinion flange, so it was either over torqued, under torqued, or there is something else going on. Really no way to tell, so i guess we will just have to see how this next repair goes.

Anyway, i know that some of us are dealing with this more than we want, but it is the source of the front end noise (in my case), which i describe as a wining noise, which is present almost all of the time.... 2wd, 4wd, coasting, accelerating, doesn't matter. Very easy to hear, and diagnose. Once i removed the front drive shaft i immediately noticed the pinion play, and the truck drives quiet as can be.

 

The front differential should not be making any noise in 2wd as nothing should be moving. We have vacuum IWE(integrated wheel end) that disengage the CVs from the wheels and the transfercase disengaged the driveshaft. One or both of those are not disengaging.

 

On the lariat version with the torque on demand transfer case, you actually do spin the front end in 2wd due to fluid drag on the transfer case internal clutch.

The noise that I was getting was not from a wheel end grinding but it was definitely a bearing noise. When the driveshaft is removed the pinion flange could be pushed in and out of the case by .009”, it should be 0!

 

Matt, sounds like you did your homework troubleshooting, good job. As far as the problem, I'd lean more to something not right with reassembly. As you know, you aren't the first with front diff trouble, seems like others that had the same, and rebuilt the diff, that was the cure, and I don't recall anyone coming back with the same trouble a second time. Good luck.

 

What climate are you in and what oil are you using?

Ford has changed their spec on the front differential fluid in cold climates to Motorcraft XY-75W85-QL Synthetic Hypoid Gear Lubricant

 

Sorry to reactivate this thread after 6 months. My 2019 Lariat just got the frontier diff internals replaced after only 33000km. Bearings failure.

You mentionned “in cold climate”...but in my book 75W85 in the only recommendation, regardless the climate. Do I miss something??

 

The specification was (still is for those vehicles) 80W90 non-synthetic for the front axle until recently. I believe the previous poster is referencing a TSB.