2023 Timberline 4x4 front differential actuation

[hdmoney]

Hi all, I have a 23 Timberline that I bought used with 20k miles on it. It has some issue with the front axle/differential that I want to get to the bottom of.

- OASIS report shows axle issue addressed at ~2000 miles

- When driven in 4A or 4H a bang and slip is felt in the front end, it feels like internal to the differential to me, rather than the wheels binding a little and digging in to go, it feels like something looses grip or tension and it "slips" for lack of a better term. The best way I can compare it is to a failing GM Auto-Lock hub circa 1982 lol.

- How the heck does this thing actuate 4x4?..there are no IWE's like the days of old and I can only see the 2 wires for the VSS going to the knuckle (I am half blind so...)

- The stealership "mechanic" told me he has to do a vacuum test (after having it a month to fix the BLIS system - that's still broken)- it does not have vacuum IWE's - so i brought it home to go to another dealership this next week. I got into the ford service manual and still can not see how it actuates 4x4, to make it even worse it started snowing in NE Ohio now and the garage is too full to go dig into it more. It does not seem feasible that the front axle is "live" all the time and solely uses the transferase for the only disconnect in the system, it would seem like it would destroy the front axle rather quickly and kill mpg...idk...

- Avoid Liberty Ford Brunswick, OH service dept. Any recommendations on NE OH Ford mechanics that are not incompetent maroons?

TIA
~HDM

 

[LokiWolf]

If it indeed has no IWE's, yes the axle is indeed active all the time. The 2023 Lariat and above F150's with 4A are setup like this. The 2021/2022 Lariats and above with 4A had electronic IWE's. Mine(2021) work well and seem to be less issue prone than the vacuum IWE's.

The Transfer case engages the front as needed. It is a TOD(Torque On Demand) transfer case. 4H is a simulated 50/50, but 4A varies send as much as 50%.

 

[hdmoney]

I appreciate it, I was certain it did not have vacuum IWE's hell it doesn't have a vacuum brake booster why would they run vacuum IWE's lol. Seems like a mistake to make it such a pain to service the front diff on these things if its spinning all the time. Hopefully I can get a competent technician to actually dig into the problem and fix it. I expect its a bad differential at this point.

 

[LokiWolf]

I appreciate it, I was certain it did not have vacuum IWE's hell it doesn't have a vacuum brake booster why would they run vacuum IWE's lol. Seems like a mistake to make it such a pain to service the front diff on these things if its spinning all the time. Hopefully I can get a competent technician to actually dig into the problem and fix it. I expect its a bad differential at this point.

Our 2020, 2017, and 2015 Expeditions all had vacuum based IWE's. Little vacuum pump up in the corner of the Engine bay near the firewall.

 

[duneslider]

In my quick search the 2023 timberline appears to not have IWEs but I did not find anything giving details on the actual 4wd system that is used in it. So, based on that I would assume it is live all the time. I still don't think a bang and slip is normal or should be happening but does that bang and slip just happen once like when it is engaging? Or does it keep happening?

 

[DieselMonk]

Mine doesn’t bang nor slip. But I can feel the front tires biting.