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4WD not engaging correctly

WRCLVR

WRCLVR

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2017 RAM Laramie 4WD, HO CTD RS69RC Aisin 67A completed AND latest Aisin flash done 2 months ago. Bilstein shocks and ARE topper no mods at all,
Went to tow my Travel trailer 2 days ago up a low gradient 1 in 15 gravel road and the truck did not seem to engage the front drive axles . Ended up having to get a tow up the hill FTL...
i have the rotary controller 2wd/4wdlock/4wdlow with a neutral button below it
I checked for codes suing my autel scanner but did not find any on the 4WD system.
Stopped with brake on and shift lever in neutral.. press 4wd and after a few second the 4wdlock light shows up on the dash. Turn to 4WD LOW and that light turns on after a few seconds.
Either 4wd mode the front wheels do not show any drive motion, nor do I get any driveline snatch turning the wheel and drivng forward, HOWEVER in 4WDLOW the truck is def in low range, but the front wheels dont provide power . This was watched by someone who is familiar with AWD.. the observer said he could hear the 4WD switching /moving when the knod was truned. No gravel either from the front wheels under a good acceleration test.....
All fuses under the hood seem fine too ( took them out and re-inserted after verfiying them to be good with multimeter..

I am at a loss and am asking for help for anyone that can help on this....
 
@H3LZSN1P3R Appreciate it. Checked mopar online and they want $566 for it. Yikes ...Not sure I trust the Ultra power or Dorman parts on Rockauto ` $160 -180. Standard Motor Products is $401....any one use this?

Remove and install is 4 bolts and 1 electrical connector after jacking up the passenger side front to prevent diff fluid leaking out. Any caveats /issues before I order ...also is there a gasket for it that I need too?
 
WRCLVR said:
@H3LZSN1P3R Appreciate it. Checked mopar online and they want $566 for it. Yikes ...Not sure I trust the Ultra power or Dorman parts on Rockauto ` $160 -180. Standard Motor Products is $401....any one use this?

Remove and install is 4 bolts and 1 electrical connector after jacking up the passenger side front to prevent diff fluid leaking out. Any caveats /issues before I order ...also is there a gasket for it that I need too?
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I would remove the actuator keep the connector attached and have someone switch it to 4wd with the truck in RUN engine NOT running first to see if it’s working before replacing it. If it works then switch back to 2WD before reinstalling it so the collar will be aligned for reinstall.

I have not removed one on the 4th gens i cant say if it has a gasket or not but it likely does but RVT will work to reseal it if the gasket is not reusable.
 
@H3LZSN1P3R Ok I appreciate it. I looked but dont see the diaphragm being replacable separately either.

Despite owning the truck from brand new I keep learning things about it. Like I should have been using the 4wd regularly to avoid issues with the actuator. Nothing in the manual about that....:-(
 
WRCLVR said:
@H3LZSN1P3R Ok I appreciate it. I looked but dont see the diaphragm being replacable separately either.

Despite owning the truck from brand new I keep learning things about it. Like I should have been using the 4wd regularly to avoid issues with the actuator. Nothing in the manual about that....:-(
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No the actuator is non serviceable as it is an electronic unit unlike the old vacuum ones

It does look like the unit has a built in Oring though
 
Ok thanks .. I had my wife operate the controls this morning and could not hear anything . i was under the truck and engine was running ...I also had her redo and i had my hand on the actuator...could not feel anything either. I also just tried what you said with the truck not running but in RUN. No sound of actuator.
i may just try disconnecting the electrical connector , cleaning with contact cleaner and re-connecting.
 
WRCLVR said:
Ok thanks .. I had my wife operate the controls this morning and could not hear anything . i was under the truck and engine was running ...I also had her redo and i had my hand on the actuator...could not feel anything either. I also just tried what you said with the truck not running but in RUN. No sound of actuator.
i may just try disconnecting the electrical connector , cleaning with contact cleaner and re-connecting.
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Sounds like you found the issue, you could test for voltage at the plug to see if its the actuator or wiring issue
 
I use my 4WD regularly, any gravel road we go on I select it. What I noticed in your description was when you selected LOW you did not mention that crash avoidance and traction control or stability control switches off.
I think you are on to it with the actuator not engaging the half shaft. You feel the steering go heavy instantly. And while in this area I have to say the LOW range on my truck is insane, I was impressed with the ratio.
 
@T143 moving to 4WD the ESC does flash a message on screen saying it is switching off. Sorry I did not mention that before. I assumed it was doing that as part of the normal switching routine ? I apologize for that oversight...

Yes the steeering does not go "heavy" at all nor does the actuator make any noises like it is switching to 4WD. ESC button on center dash works and msg light turns on on dash. Light turns off when you turn it off..

Sorry for the long posts on this but Im retired and money is really tight so that is why the many questions...
 
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No worries, and now its even more likely its that actuator just make sure as previously mentioned the actuator is receiving 12V at the connector then I would remove the actuator to check maybe its just stuck because it was never used.
 
sounds like i will have to do that electrical test lol once the hurricane gets past..... From the parts diagram, the fork on it moves the hollow shaft collar in the axle housing to engage disengage the 4WD. sure hope that the shaft collar is not frozen.
If just the actuator I will replace....hopefully that will do the trick.....
@T143 appreciate the advice and replies.
 
WRCLVR said:
sounds like i will have to do that electrical test lol once the hurricane gets past..... From the parts diagram, the fork on it moves the hollow shaft collar in the axle housing to engage disengage the 4WD. sure hope that the shaft collar is not frozen.
If just the actuator I will replace....hopefully that will do the trick.....
@T143 appreciate the advice and replies.
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The collar should not be jammed there is enough oil and clearance there. The shift fork on the actuator could be tapped a few times to see if it “frees up”
 
Found Aaron Rose on youtube who did a deep dive into the 4wd actuator . Looks like the housing for the electric actuator leaks water into it and the circuit board burns up a few components. The forward and reverse action is monitored via a sliding magnetic button and lead screw.
It may be worth it to identify the components on the board and repair/replace them esp at almost $600 from RAM. Once i get the new unit in I will have a shot at the old one

link for you guys :
 
Sorry for not posting back. I replaced the faulty unit with an OEM Mopar unit sourced from Geno's Garage (happens to be local to me here in Atlanta). Cost was a lot less than the local RAM dealers quoted. My local mechanic installed in about 30 minutes plus changed the front diff oil for $110 total. Ram quoted me $600 for the unit plus a required diagnostic work fee ( $200 ) and 2 hours install @150 /hr. Uuunnh that was a hard no....
Shocked to see both new unit and old one are made almost entirely of ...plastic..except the fork. New one works fine and did not need coding etc. I have yet to open the old one to check to see if the electronics are bad. However the fork does slide with almost no pressure, implying the internal plastic gears are toast.
 
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