4WD Won’t Engage/Disengage

The extra force needed could have been from being in Park (Im assuming) when you manually shifted it.

If you chock the front wheels and lifted the rear end from the receiver hitch, then put the trans in neutral and give everything a spin that should free it up. You could even try manually shifting again to see how it feels

 

Some seem to say it can take a bit of work to get it to move back manually, while even needing the vehicle in neutral. Not sure the best way for anyone to do that safely. For me it was as I was about to get onto a snow road I spun, so I stopped for a second to engage 4wd, after a large clunk, (engaging) it remained in 4wd and blinking. Assuming this is the case as generally the front driveline spins freely in 2hi. Tried to clean the connections, tap lightly with a hammer, top off fluid, and disconnect the battery for a bit, no luck on all of that yet.

I have yet to manually move the shift rod on the transfer case as you mention here. A bit nervous about losing placement of the clock spring internals, although the actuator itself is likely bad from what I am seeing in other forums. Odd how they can just suddenly die out like this, I kind of hopped on this early before noticing it was 3rd gen, while mine is a 2nd gen. Issues seem pretty similar here, not meaning to thread jack. Let me know if you find anything, will do the same. A bit nervous about taking it to Toyota and then chalking it up to modifications, or blindly attempting at the actuators when in reality its something else potentially simpler. I saw somewhere you can try to pull the fuse to trick the system to reset as well but lost track of which fuse.

 

There are so many unknowns and guesses here it's hard to troubleshoot without actually seeing the system and testing the items. I've posted a couple shots of what ground together when you shifted into drive prior to shift completion. The dogs on the inside of that low range sleeve tried to engage the dogs on the tcase input while the input was being spun my the motor. It's possible that the ends of the dog teeth were mashed together too violently. This means they're slightly deformed, maybe some material is rolled up, and there's now tightness and no clearance in the engagement. This is just a possibility as I have ZERO idea how severe this event actually was. But, it seems severe enough that some problems are caused.

It's also worth noting the collar and input may be totally fine and it's not out of the question for the grinding of the dogs to kickback through the shift system and damage something else such as the internals of the actuator or the shift rail.

It seems initially the ADD should be stuck only because the tcase wouldn't shift to 2wd since the ADD shift doesn't occur until completion of the 4HI->2HI shift in the tcase. Now that the tcase is in 2HI the ADD should be willing to shift if everything is recognized as a valid state. If you get the tcase into a recognized valid state the ADD should shift. Once you attempt a shift after that you'll know if it's going to give you bigger problems.

 

Still can't understand why these trucks do not have an override that prevents damage if you shift into drive before out of 4low. Of all the technology they pack into these, that seems like one that would be an automatic.

 

IMHO, there's already too much built into the electronic 4wd system. It just takes time to learn it and never rush it. The actuator driving the lower range dog full on is weird. I've had some grinding if I let the brakes slip, even a speeds less than the 2mph noted in the OM.

My friend just installed some twin sticks for the problematic J shifter on his Bronco. I'm very jealous.

 

My Toyota dealer gave me Mobil 1-75w90. they said that's what they only use..

 

What did they charge you? The OEM vs Mobil 1 is about 7-10x the price. Hope dealers aren't charging for OEM transfer case fluid change and putting in Mobil 1. Wouldn't surprise me in the least though.

 

The issue has been resolved.

Once I timed the transfer case actuator gears correctly and reinstalled, the system was clear of errors and confirmed in 2WD after start up (ADD disengaged and Tcase in 2H).

I held my breathe and switched to 4H, it engaged with no issue.

Thank you to everyone that responded with helpful comments and suggestions! Great forum to be a part of.

 

Awesome man! I scheduled something with Toyota Friday since it was certified used they should hopefully cover it. Will probably keep at this in the time being to try to synchronize the system. Seems in your case your problem was mostly centralized to the transfer case actuator and not the 4wd actuator?

I am getting a electrical shorting noise when it attempts to transition so I think mine may be more deeply rooted but hopefully I can just fix it before Friday.

 

Nice man, good luck and I def feel your pain.

My issues were strictly w/ the transfer case and actuator, not the ADD, which is the actuator for the front diff.

Actually, my issues were user error, but the resolution was with the transfer case.

 

Makes sense, book marking this for later. I just tested to make sure the tires and the front driveline was spinning and it indeed is which makes me guess ADD is my issue where I see soldering issues as potential culprits. Readings on the ohmmeter were a little low but I could still get a decent reading.

 

any idea what buggered it in the first place?

 

Me not confirming it was fully engaged going from 4L to 4H before I put it in drive.

 

I have updated this post again with an edit. After trying 4L for the first time I had some issues and had to manually re-adjust back to 2H with the shift rod and retime the gears. I provided some picture and explanations in the following Imgur link, hoping this can be used as a reference in the future if someone finds themselves in a similar situation. The only resources I could find on the gear timing were foreign language YouTube videos of a newer gen Hilux (Same Transfer Case, same actuator, thankfully).... but they were in Tagalog and Hindi.

If anyone comes across this in the future and has questions feel free to revive or DM me and I will help best I can. The GIF in the photo link was actually me talking through the shifting but Imgur strips the sound and converts to GIF).

https://imgur.com/a/RJWLnvG