4WD Issues

About a month ago I noticed my 4WD taking a really long time to disengage. The light on the dash would just blink and blink. Then recently, 4WD wouldn't engage at all. I would be in neutral, clutch in, foot on the brake and every time I flipped the switch, both the 4wd and 4lo lights would blink. I thought I had it narrowed down to the front actuator, so I ordered a new one and replaced it. Smooth install and new gear oil. Then I went to test it and as soon as I started the truck, the 4hi light started blinking. The truck was stuck in 4wd. I drove around for a while and wasn't able to get it to disengage. Out of ideas I bought some white lithium grease and cleaned and regreased my old actuator. I tested the little motor with a 12v battery and it spins fine. I soldered the connections together and put it back into the truck. Now I am stuck in 2wd with the 4hi light constantly blinking. I am completely lost. Any help or information would be greatly appreciated.

Also, when the 4wd used to engage, I would hear the clicking of a relay behind the glove compartment of the dash. I no longer hear the clicking now that nothing is working. Could this be part of the issue?

Thanks!

 

Also, The last time I installed the actuator, The sleeve inside the diff was in the 4wd position. I slid it to the 2wd position as the actuator was also in the 2wd position.

 

What year is your truck?
Have you looked at your transfer case actuator?
The vent hose on the transfer case actuator is bad about cracking and coming off which allows dirt and moisture inside and corrodes it.
Also alot of info compiled in the thread below.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

It works best if the truck is moving. You only stop and go to neutral if you are shifting to low range, and even that works best if you're slowly rolling under 3 mph. It sounds like you may have other issues, but when going into and out of 4X4 just flip the switch while driving. If you try to do it at a dead stop, you have roughly a 50/50 chance that the gears are properly aligned to mesh. If the wheels are turning 4X4 will engage when everything lines up

If stuck in 4X4 it usually helps to put the truck in reverse and drive 10-15', then pull forward about the same distance. Sometimes the gears are bound up tight. Especially if driven on a road surface with good traction. You may have to repeat the reverse, forward dance several times. Not unusual with any 4X4.

 

It's a 2006. I have not looked into the transfer case actuator. I have only replaced the differential actuator. I did replace the vent hose as well. Lots of really useful information in that thread. Thanks!

 

Thanks for the information! I usually flip the 4wd switch at a stop then, when I begin to roll it engages. Sometimes I do have to reverse some to get it to engage. I almost always disengage 4hi while driving through.

Unfortunately for me though, the issue I am having has nothing to do with the method of how I am engaging 4wd. There is something mechanical wrong.

 

After reinstalling the new differential actuator, I drove it around for a while in 2wd and now it will engage 4hi disengage with no problem. It will not even try to engage 4lo though. It immediately blinks the 2, 4wd lights on the dash when I flip the switch.

 

Does it beep when you try to go to low or just flash the lights?

 

No beeping. It just blinks.

 

Most likely a problem in the transfer case actuator, you can test the limit switch voltages at the module if you want but you said it goes into 4wd now but not low so that tells me to look at the transfer case actuator and L4 switch.

 

Ok, thanks. Ill definitely look into it.

 

Is the 4wd actuator and transfer case actuator the same thing? I have replaced the 4wd actuator. Here’s a picture of the part I replaced already

 

That is the ADD (Front Axle Disconnect) actuator, the Transfer Case Actuator is on the back of the transfer case.
The vent hose I was talking about is circled in red.


Internal drawing of it.

 

We’ll, this is definitely the problem. I removed the transfer case actuator and opened it up. It is full of water and mud. The breather tube was also try rotted and split. I’m going to try to clean it up and degrease everything. If that doesn’t work out then I’ll end up replacing it. Thanks!

 

Make sure you get it timed correctly when you put it back on.

 

I marked the gears locations before I took it apart. I’ll update when I get it back in.