Partially stuck in 4WD lo?

Hi, I know there are a ton of Posts on four-wheel-drive, but I have not found one quite like my situation. Over the weekend I was using 4lo in my backyard while I had a heavy trailer of soil hooked up. After I was done, I switched it back into for high before I parked the truck. As I went back out on the road today I tried taking it out of four hi and it would not go back into 2wd. It would also not go back into 4hi. During this I had also stupidly hit the posi lock button so I also had the VSC off light illuminated. So I had both four wheel lights flashing, and it would not shift into or out of four high. They just kept flashing. Also, I noticed the truck pulling to the left especially when slowing down. It seems like possibly one wheel is stuck in four low. I finally got it to disengage and go back into 2 WD by backing up about 50 feet kind of aggressively. Later on, I tried to go into four high again and the same thing happened with the truck pulling to the left and wheels screeching at slow speeds. Does it seem to indicate stuck in four low. But I again was able to get back in 2wd by driving in reverse a bit. I have used 4hi regularly in past and never had trouble but hardly ever use 4Lo and probably shouldn’t have done so this time. I have thought about leaving the battery undone overnight to see if it releases. I’m also afraid of getting stuck permanently in this in between state, if I keep trying to go into high. Thoughts?

 

Whens the last time you serviced the front diff.

 

Could be a few things causing this.

Since you have a 2WD option, that means you have a V6 4Runner, which you don't indicate anywhere. The front axle has a disconnect on the passenger side of the differential. It's possible that it's getting hung up in there, preventing one side of the front axle from disengaging when you take it out of 4WD. 4HI or 4LO shouldn't matter. Only the transfer case on the back of the transmission operates in 4HI/4LO and then send power to the axles.

The other potential issue are the shift solenoids on the transfer case itself potentially starting to fail, which could prevent the transfer case from shifting or only partially engaging 4WD, either HI or LO.

 

Thanks. I did forget to specify V6. Sorry about that. I’m guessing the tire screeching then might be caused by fact that only one side being hung up in the front as opposed to hi vs lo issue? None of this was an issue before (successfully) using 4lo a bit with the heavy trailer. When I was done with 4lo I shifted into neutral and heard what I assume was transfer case disengage when I moved switch from 4Lo to 4Hi. The I drove 100 feet in 4Hi and shut the engine off till next day. So it was in 4hi overnight before what I post above happened. Also when I said posi lock above I really meant the differential lock button. So I’m guessing disconnecting power for a bit might free things if electrical in nature and if not problem might be mechanical? Last service of diff unknown. I had 4Runner about a year and 8k miles. ( been on my mental list of things to do) 207k on the odometer. (Sorry if my posts are too wordy)

 

If you were stuck on 4lo, you wouldn't be able to drive near 60MPH. It seems your ADD ( front differential) is getting stuck. Check for oil level, sometimes the actuator need to.be replaced.