Another 4wd thread

Ive read a ton on here about this issue. you guys are ridiculously knowledgeable so I have to ask. 2015 dbl cab 4.0. ADD has been opened, cleaned, and tested. Appears to be working correctly. When I turn knob to 4hi, 4wd indicator, 90% of the time, just flashes and wont go into 4wd. If i tap on the TRANSFER CASE actuator, it will go into 4wd. it comes out of 4wd no problem. would this be indicative of a bad switch in tcase actuator, or gummed up stuff inside the actuator? thankful for any insight.

 

Most likely the transfer case actuator is getting stuck. May need to replace entire actuator.

 

If you can tap on the actuator and get it to work then yea most likely the issue is in the actuator, you can check limit switch voltages to see which one(s) are out of range but the actuator is pretty easy to get apart providing the bolts aren't seized.
Make sure to take care that the main gear stays in place or you will have to re-time it which can be tricky.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

Thanks for the replies. Gonna try everything I can before opening that actuator up. Reading about the timing horror stories has me almost willing to just carry a small hammer with me to get it to work when I need it.

 

Just for reference this is where the gear should be with the Transfer Case in 2wd (shift rod all the way in).

 

If I take that cover off, is that gear going to stay on that shaft or is it looking to fall off easily?

 

If your careful in taking the cover off it should stay there, also take care not to cut/roll the o-ring when reinstalling the cover.

 

Thank you.

 

So got that cover off. Only snapped one of the 10mm. Inside was surprisingly pretty clean. Lots of yellow grease, hardly any contaminants. Cleaned everything off, gear stayed in place. Put it all back together to test, with no grease since I still have to drill and tap for new bolt. Still no joy. Same situation. 2hi to 4hi, green light blinks, front drive shaft engaged, front add not engaged. Tap on tx case actuator and front add engages and green light goes solid, into 4wd.
Any suggestions would be greatly appreciated. Happy 4th of July to all!

 

Might be worth a try to sit in your driveway and cycle the switch from 2H to 4H and back a dozen times or so with a tap to see if it clears up the problem. The goal is to clean the contacts so it will work again. Is the 4H back to 2H working without any taps? If so, that is a good sign. My truck makes the shift fine, but when I exercise it like this the last cycle is usually much quieter/smoother than the first. The change is even more obvious when doing the the 2H to 4L cycle: less noise and smoother after a few cycles.

 

Before I took it apart I went for a ride and cycled it probably 20 times no problem. Hi, lo, 2wd. In and out. Then at some point it starts to act up. Jack up front wheels. Cycle it in and out of 4hi and it goes in when tapped, and comes out without tapping. Could the actuator motor be a little weak and not get it all the way into 4wd when a little warm?

 

Kinda sounds like the motor may be getting flaky, it's odd that it always comes out of 4wd though.

 

Got it. I agree with DM93 and meant to also add that until you get things figured out and back to normal, I wouldn't perform any exercise/test shifting to 4L, especially if you're not home in the driveway...

It may not shift back to 4H.... That would be bad.

 

When I went on my ride, I did a few 4lo shifts. No problem at all. Its in my driveway. Im not gonna run it as a main car until it's fixed. Just did all new lca's shocks and brakes. Rides like a new truck. The amount of rust underneath this truck is astounding. It has 82k on it and looks like it has 282k. I guess I have to dive into this motor and check it out.

 

So my understand of your situation is that the tcase if fully engaged because you said “front driveshaft engaged, front add not engaged” then when you tap on the tcase your front add engages. This sounds like the 4wd computer is not sensing that your tcase is in 4wd. Does the tcase actuator move further went tapped or does the front add just engage?

 

Not sure whats happening with the tcase actuator when I tap on it. I thought for sure it was going to be a bad contact inside. I have also tapped the add to see if something in there was funky but that gets zero results. It's always only when I tap the tcase actuator.

 

This is a good point, I didn't think of this but I wonder if the 4wd switch on the back of the Transfer Case Actuator is getting flaky and a tap makes it make contact.

 

I was thinking maybe that as well. I've tried tapping that directly and messing with all the wires associated with the actuator with minimal results. Not sure how to actually test that switch accurately. I could check for the proper voltage but if it's actually not all the way in 4wd because of a wonky motor, then the readings would be moot because it's actually working correctly. Maybe I'll just see how expensive that switch is and just replace it.

 

If you had a friend with a Tacoma you could swap actuators. They’re actually pretty easy to remove and install.

 

Finding 2 different part numbers available on eBay that says it fits. Can anyone confirm if they're the same or not? 84222-12010, and 84222-35121. For $50, I'd try one of those switches before I replaced the whole actuator I think. Unfortunately I don't know anyone that would let me Frankenstein their truck haha. Maybe I'll just do the catalytic converter thing and go steal one in the middle of the night lol.