4Lo malfunction

2020 OR stock
I live in Big Sur, my road is fairly steep and muddy, small bumps (damn 2wd neighbors never learn), no ruts.
I was driving up in 4lo 1st gear 30-40 degree incline, ~1400rpms creeping cause no rush, and it slipped out of gear with a loud clunk and spooled like a diesel turbo. as soon as it clunked I dropped it into neutral (maybe why it spooled) and let off the gas and waited for return to idle. once it went back to idle I put back into 4lo without any issues and drove the last few hundred yards to my house. dove down the mountain in 4Hi today without issues.

Has anyone ever had this happen. I tried every search term combination I had and this particular issue didnt come up. a lot of actuator failures but no clunk and drop out of 4lo.
pending failure or random WTF??

 

sounds like it disengage but it might of broke, the only way to tell us if you engage four lo and see if the front tires spin , if they dont then your actuator broke . It could of been that you drove back home in 2wd even tho its said 4lo

 

have not actually physically looked.
But 2wd it would spin and slide in certain corners (from experience) and I crept right past them up last night after and down today. even had to reverse uphill this morning bc a 2wd car was stuck in a ditch and my not knowing it was there approach angle wasnt enough to get around. no slippage there either.
I figured it disengaged, but was wondering if this is one of those things that happens before full break or not.

 

I have not had your issue, but did have the spooling swoosh sound when I drove it in S1 once. Interestingly, I’m surprised the motor didn’t hit the rev limiter. The swoosh sound is quite loud. That was months ago just in case you were worried about that part mechanically.

 

No need to check the front tires for spinning.
The whole truck wont move if something broke.

I don't know how it could have slipped out.
But it could have, I guess?

The transfer case actuator would have not made contact with the limit / detections switches if it were not locked in fully.
When that happened, did the 4LO light flash?
Did the truck beep, or a message come up on the dash?

 

i could sworn i seen broken actuators and only works in 2wd

 

The front ADD actuator maybe? (Mounted on the front axle)
But not the transfer case actuator.
The transfer case only applies power to front and rear driveshafts.
If the truck moves in 4HI, it will either move all four wheels in 4LO or none of the wheels will move.

 

Sounds like what happened to the TFLTrucks guys, but they couldn’t get it back in 4Lo. https://youtu.be/svD7Mx2xius?si=sex3JdOSi1bSnJ32

 

yes sir thats what I meant

 

Ok.

OP said it "slipped out of gear".

I'm still trying to figure out how he lost all power to the wheels?

OP. is your truck an Automatic?

 

I can't stand the Andre guy, too bad it wasn't him driving

 

automatic.
no flashing 4lo. fully engaged and drove 40 degree incline maybe 3/4 of a mile before this happened.
loud clunk. my 8 year old got scared and ask what the noise was.
lost power to all wheels like it went into neutral, simultaneously spooled.
spool was not engine RPMs, it was in the trans or T-case. loud and had a sound like rotational metal just barely touching metal, gears/spline tips just barely touching (think very fast playing card on a bike tire but clicks were metalic).
less than a second I switched the auto selector to neutral, applied my breaks, and waited for everything to come to rest as it spooled and then came to rest.
put it back in 4lo and worked like nothing happened last 1/4 mile to my house.
next day and daily since 4hi has worked like it should. haven't used 4lo except a few times just to make sure will engage and it will.
front tires currently spin in 4wheel. we are currently having a rain storm here and its sloppy as... i verified spinning.
but also 100% couldn't get up my road right now without 4wd unless you rally car style smash and slide around. this is what i did in high school in my 2wd dodge ram d50, I creep now bc what's the rush and i beat the hell out of that truck.
had same feeling of no wheels spinning, no power as my manual trans manual selector 99 taco had when my son physically yanked it into neutral
currently doesn't act like anything is broken or happened, maybe sign of impending doom?? or fluke?
im going to check the fluid for metal shavings next day off, but currently in the middle of a 7 day on sretch at work.

 

It sounds like your ATRAC/MTS engaged due to wheel slippage. It’s quite loud. If so, it’s nothing to worry about.

 

Have you tried 4LO in S mode?

 

Automatic too.
Happened today as I haven't thrown 4Lo in so long, probably 2yrs. Got into 4hi no problem...then try to get into 4lo and the flashing and beep kept going and truck didn't go into it at all. I kept driving slow maybe 3 to 5mph just to see if it would go but nothing until a loud scratching noise took place. Sounded like a solenoid that had seized up or something and then bang...slowly went into 4Lo. I stopped and put everything back to 2wd and drove around. I waited for a few mins and went thru the sequence and finally it went into 4Lo with no issues. I tested MTS and crawl control in a gravel road etc. I think my issue was that I dont throw this into 4lo at all and things just seized after so long. I got underneath no issues...everything looks normal. No weird smells or anything. I think is fine. Should I be worried?