4x4 not working

All actuators (4hi, 4lo, ADD) are all in perfect condition and functional but when I flip the 4wd switch only the 4hi actuator actuates and 4hi flashes. I am completely lost and don’t know what to do. Does anyone have any idea what is wrong with it?

 

How often do you use it?

 

Yes, you should periodically exercise the 4x4 on a straight stretch of road.

I've found that mine has difficulty engaging when under load (accelerating, going up a hill.) It helps to ease off the gas, let it switch, then resume regular driving. Same thing when turning it off.

Should work when parked, however the point of using it is to allow the components to move around and spread the lubricant so IMO it's better if you're driving.

 

Just wondering, how do you know the actuators in the TC are working properly? It’s easy enough to open the front diff tube and actually see if the ADD is working properly.

I would check if the wires to the actuators are seated properly, or are damaged (by debris or rodents).

 

I'd find a gravel road, engage 4hi & drive it for 30 minutes. It's taken a long time for mine to engage when I haven't utilized it regularly.

 

And if it starts working, exercise it a few times both forward and reverse, hi and lo.

 

I have opened the TC and both actuators are in perfect condition. Though I have not opened the ADD actuator, I know it works because when I removed the 4hi actuator, I plugged it in while the actuator was off of the transfer case and engaged 4hi. When 4hi engaged everything worked as usual, except the TC rod did not get pulled because the actuator was not installed. In short, the ADD only works when the 4hi actuator is removed but plugged in but removed. My guess is that when installed the 4hi signal switch is not being hit by the moving piece while its installed, but it works perfectly fin when it is disassembled. I am completely lost.

 

after 11 or so seconds after actuating, the relay in the 4wd ECU clicks, and the 4hi actuator disengages. So this unfortunately cant work.

 

When the actuator's slide fork moves the clutch sleeve it should then send a signal to the ECU. And you are correct that the ADD is triggered only when the TC actuator has completed its job, so if we divide and conquer, then it leads me to believe the issue is somewhere with the ADD. Either the ADD itself, which is common, or the wiring if the signal is not making it back to the ECU.

Did you do any deep water or mud crossings lately? Go for the low hanging fruit and check if the ADD connector is corroded, dirty, loose, or damaged.

 

Also check that the breather/vacuum lines are connected to the front diff. There are 2.

 

The ADD connector is totally fine and I know the ADD actuator works because when the 4hi actuator is removed but plugged in, it makes a noise when 4hi is engaged. But when the 4hi actuator is installed, the ADD actuator makes no noise.

 

Then it sounds like the opposite. If the 4hi actuator, when installed, is activated but the ADD does not get triggered, then the ECU is not receiving the signal from the 4hi actuator that it was able to successfully slide the fork.

 

Exactly. Now the question is why does it only work when removed and how do I fix it

 

When you take out the actuator and activate it the slide fork makes it to the opposite end and sends a signal to the ECU, so that means it's not the wiring. But when installed it does not send the signal, so that means either something is obstructing/preventing the actuator from successfully sliding the fork OR the actuator has somehow lost the strength/ability (wear n tear) to do its job when resistance is present.

I would try:
1. Taking out the actuator and use your fingers to slide the clutch sleeve back and forth see if there's any noticeable resistance.
2. With the actuator in hand, apply the same amount of resistance from step 1 to the slide fork, activate it and see if it can successfully trigger the ADD. Maybe it slides the fork but not all the way?

 

Are you referring to the ADD actuator and the front differential? I am referring to the 4hi actuator on the transfer case. I just want to confirm there hasn’t been any miscommunication.

 

@Cruzer if you are talking about the add actuator and the the piece that the fork moves, I think I can transfer your suggestion to the transfer case actuator (Which I mostly have) The 4hi actuator has a gear that moves a rod with teeth. By my recollection, I needed a screwdriver pushed into one of the teeth to pull the rod and to push it back in only required my finger. I did not test the strength of the actuator motor however. Do you know how much force it should take to move the TC rod whether it’s a lot of force or a little?

 

@Cruzer however I do have reason to believe my 4hi actuator is working properly because when I actuate 4hi, my actuator makes the same noise in this video at 8:05
https://youtu.be/47m7QAPrpsI
skip to 8:05 to hear the noise

 

TC actuator. I don't know how much force, which is why I suggested using your fingers and then try to replicate on the actuator.

 

Yup, I've watched that video a million times. The only difference with the actuator in your hand vs in the TC is the amount of resistance the motor has to overcome. Check out this video at 7:34. The actuator has to be able to turn in order to trigger the switch, which it may not be doing when it's installed. Maybe the rod is sticking further in/out than it should be and therefore prevents the actuator from rotating enough to hit the trigger.
https://www.youtube.com/watch?v=2HKEluXwbZo

 

In the video, he said it has to be pushed all the way in. Which I made sure to do when I removed it.

 

@Cruzer I just opened up my tc actuator. I felt the strength of the motor when 4hi was activated. It was plenty to pull out the rod and I could not stop it with my fingers. Another thing to note is that it seems the spring inside of the actuator is getting tension. I’m not sure if that’s to help build up energy to pull the rod out, but it is happening. Any other possibilities?

 

Can you put marking paint (like they do on gears) on the trigger? The actuator needs to rotate enough to hit the trigger. Put marking paint on, install the actuator back onto the TC, then do a test.

 

So, if I understand correctly, with the TC top cover off you get a solid 4hi light when you select 4hi? It does not flash?

 

This used to be the case but suddenly the 4hi still blinks and the add actuator beeps and clicks. However, the issue of the 4x4 not working is in the 4hi actuator. The add can be dealt with later.

 

On mine the 4hi would flash like you were describing. I took the TC actuator apart and it looked fine. No rust, clean grease, and no broken connections. I ran the motor and everything looked good. Since I could not find anything I checked the little micro switch. When I checked continuity through the micro switch it was really high. Like meagohms and kiloohms. I cleaned the micro switch and rechecked it. It was around 1 ohm. Put it all back together and have not had a problem since. You might try checking the resistance on the little micro switch.

 

Ok great! So what do I need to buy to check the continuity? And what do you do to clean the switch?

 

You can check the resistance with an ohm meter (digital volt meter). You don’t need anything fancy. Push the arm of the switch in and see what resistance you have. I actuated mine several times with my finger and it was pretty consistent. If it is a few ohms you are probably good.

I would definitely check the resistance of the switch before I tried to clean it. If it is high. I would try spraying contact cleaner in it first while working the switch. I ended up having to take mine apart (it is small and easy to break so I would be careful) .

Here is where I told someone else how:

https://www.tundras.com/threads/2007-2020-transfer-case-actuator.61182/page-3#post-2311680

 

@huntertn thank you so much for the suggestion. I’m going to try this but I am confused as to how this could be the issue because the switch works perfectly fine when the actuator is off of the transfer case.

 

The best thing I could find was white out. I marked the trigger and the making did not show up on the piece that hits the trigger. Any other suggestions?

 

So just to clarify, you’re saying that when you reinstalled the actuator and switched to 4Hi, the actuator did not touch the trigger. Is that correct?