Could use some advice for Transfer Case Actuator replacement

I had a jeep CJ. You could put the transfer case into 4-high, neutral, or 4- low. I’m not sure how the internals of the Toyota transfer case works and if somehow you’re timing is making it act like it’s in neutral and not allowing the transmission to do anything. But in previous comments on this and the other thread, one of the guys starts off by saying he’s not really into computers But then he goes on and talks about computers. He said that underneath the passenger floor mat there’s a door with access to the actuator module computer. He said he unplugged it there and I think disconnected the battery so that it had no power and then reconnected the battery and then the computer to reboot it? Something like that. If you’re timing is right, Then it’s obviously something else. But I would first check to make sure that you had the timing correct. It’s not hard to do. But it took me a while to understand in my mind how it works. Once I lined up the three spring tabs underneath the gear in the correct position as indicated previously In this thread, It worked the first time. Sorry about your luck!

 

Thanks for the reply sixweeds, as it turns out it was a combination of timing and sequence of steps in ensuring the timing is in correct relation to the switch possition when the key is turned on. I reset the 4wd computer behind the glove box and went throught the correct sequence. An audible thud was heard and everything was back to working. I confused the computer. Lesson learned....

 

Whew! Glad you got it working!

 

First, fantastic Post and responses. Extremely helpful.

I have a 2008 Sequoia. I searched all over the net but could not find very many people talking about problems with their 4LO light flashing. When searching the problem instead I would get loads of Tundras with the same problem. Luckily, they seem to have the seem actuator systems and problems.

Read a lot and watched a lot of videos on diagnosing and repairing for this problem. Was, hesitant to tackle this myself as I only have limited experience working on cars. Finally got the nerve to go for it when I got a quote to fix the problem for over $4000.00.

Found my problem as stated was a bad vacuum tube not connected to the actuator housing. That I assume lead to the dc motor going bad and the gears inside having a bit of rust. Tried in vain to find the motor but had no success. Finally bit the bullet and ordered the entire actuator assembly from Rockauto. Cost was a little over $500.

Replaced only the actuator motor portions of the assembly. Followed instructions here and from the video I watched. Everything went fairly smoothly though when I restarted the vehicle the 4LO light still blinked and it was making an awful beeping noise. Took the 4LO side back off. Made sure the rod was pushed all the way in and made sure the gears in the motor assembly were in the same position as shown in the images above. Reinstalled everything and restarted the vehicle again. Happy days no blinking lights and no beeping.

Have tested the 4HI and 4LO on a gravel road and it seems to be engaged. Heading to a friend’s farm later to give it a better test. Hopefully all is good.


Thanks again for the thread!

 

You are so welcome. For years I would get help from YouTube or a Forum that was indispensable. But I never let the poster know how helpful I found it. I finally decided after this issue to return the favors. From now on, whenever I can, I'll document what worked for me if I think it will benefit others. Pay it forward...

 

Everyone,
Thanks for all the time and info you have put into this forum. I really appreciate it. I have the blinking 4 hi issue this all started after my truck got stuck in 4 hi this winter.
I had been using 4 lo as well during this timeframe. I am now getting the slow 4 hi blinking light 10 x's and then the 4 hi light goes to fast blinking after the initial 10 slow blinks and I am not going into 4 hi. I have replaced the 4 hi actuator (top) motor and housing. Now i hear the motor running when I switch my toggle switch from 2 hi to 4 hi but thats is the only thing that seems to happen. I have been reading the forum and see the Tundra Transfer Case Actuator Repair document that Sixweeds has provided thanks so much for this information.
I am wondering if my timing is off on the new actuator motor. I noticed in this document it states to have the 3 springs contacts at the 3 o'clock position if the Transfer case is at 12 oclock.


But then down in the document mentions you need to assemble this completely different.

The below picture puts the contacts at more like 12 o'clock.





I am just trying to figuire out what I am doing wrong on my alignment if that is even my issue.

Is it also true that I could hook up the transfer case actuator's not installed and switch from 2hi to 4hi and reset the actuator gear settings as well as once the 4x4 ecu see's these actuators go into the correct position then I should hear the front 4x4 ADD actuator switch the front driveshaft into 4 hi?

Thanks for all your guys help much appreciated.

 

Here is the document I am referring to as well.


Thanks again everyone.

 

In my situation, my 4-Hi and 4-Lo didn't engage. It just blinked. I never counted the times it blinked. Just continuous blinking and no actuation. But, after going through the steps I wrote about, it worked.

To your points: The three spring tabs need to be aligned in the position shown in the first picture. The tabs that are visible are on the underside of the gear, but in the picture, I turned it over so you could see the spring tabs. When you turn it back over and place it in position, there are two ways I described how to know where to put it. One was by aligning the tabs with the rib on the actuator housing as shown next to the red arrow. Another picture in my document shows that there are three marks on the circular contacts and when it comes to a stop, on mine, there were three little "burn marks" or "indentation marks" where you could see where the springs tabs stop their rotation. Does that make sense?

The second picture simply shows that after you have put the gear in, then you install the part (pictured in my blue gloved thumb) make sure the tab under my thumb goes into the space between the big wire spring ends. Does that make sense. Don't get hung up so much on the clock position. I was just trying to be more descriptive. But it you get the 3 spring tabs on the three little burn marks like this photo. (Page 5, step 13 in the document).



And make sure the rod is pushed all the way in. I hope that helps! Let me know if you need more clarification and I hope I didn't confuse you more!

 

Sixweeds,
Thanks for the clarification. You cleared this up a bit I will reference the first picture the next time I get a chance to take mine apart.
Yep, I made sure the 4 hi rod is all the way in and i also tested that it will go in and out freely.
I may have another issue as after re-assembling about 5x this weekend with new parts I hear the actuator for a second or so then it stops but I don't believe the front diff is doing anything.
That may be my next stop.

Does anyone if there is a troubleshooting step by step in the service manual for this issue?

Thanks again Sixweeds and all on the forum very useful forum.

Thanks,
JTO

 

I've read here and heard from another guy that there is a 4WD actuator computer under the carpet on the passenger up near under the glove box. Supposedly, this can sometimes get confused. The solution seems to be to pull back the carpet and unplug this computer...wait a few minutes, then plug it back in, rebooting it. These guys said that it worked like a charm.
You said you replaced the actuator motor and housing? Or you took the guts out of another actuator and replaced components in your housing with those? From all I've read, in order to get the actuator housing separate from the transfer case, you need to drop and disassemble the transfer case to remove the actuator and rods. Can you explain what you mean and what you actually did? That might help others. If you removed the actuator housing around the rods still in the T-case, then it would be ver easy to replace an actuator from Rock Auto or a salvage yard, but not the rods. At least $500 from Rock Auto, but easier than opening the actuator case and messing with the gears!
Thanks, JTO!

 

Sixweeds,
I replaced the 4 hi actuator motor/gears and housing with a replacement from rock auto this weekend. I just took the old parts off and installed the new parts I didn't remove the actuator housing only replaced the 4 hi actuator and top cover (hat).

I hear the actuator motor on the transfer case however still getting the following:
10x slow blinking 4 hi and then it switches to fast blinking 4 hi light so not sure what the heck is going on.
I don't hear my front ADD diff engaging but not sure if that is due to a transfer case issue as its not switching into 4 hi or the front axle ADD is not engaging due to another issue.

Anyway thanks for all the advise.

Thanks,
JTO

 

JTO,

Please post here if you decide to unplug (reboot) the 4WD actuator under the passenger carpet (battery first) and if it clears up your problem. If/when you do, perhaps you could share if you resoldered the connections for the motor, or just replace all the "guts" together from the new one?

Sixweeds

 

Sixweeds, I will let you know I already tried the 4x4 ECU disconnect up behind the glove box and that didn't change my results.
I am will update as I go along with my troubleshooting of my issue.
I have already replaced the 4 hi actuator-gear / hat assembly with a replacement from Rock auto and it didn't fix my issue.
I am going to check alignment of the gear next chance I get.

Thanks,
JTO

 

Well,
No good news.
I have tried the following.
Since I can hear my 4hi transfer case acuator running when I switch to 4hi twice actually.

once when I first switch to 4hi and then again in about 10 seconds.
Here is where I see a issue.
I never hear the front axle A.D.D acuator do anything.
I removed the front axle A.D.D today and I can apply 12 volts between pin 1 red/black and pin 2 red and I get the A.D.D acuator running.

When I pin-out the voltages on the front A.D.D I see voltage on pins 1, 2, 4 with the key to my truck in acc mode or when I switch from 2wd to 4hi.

At this point I am quite confused on why my front A.D.D acuator is not engaging unless my transfer case acuator is still having a issue and not sending the signal to allow the front A.D.D to engage.

I also checked and my front axle's engage when the shift collar in the axle is shifted from 2wd to 4wd so nothing is hosed up in the front axle.
manually putting front axle into 4 wheel drive.

I disconnected my 4x4 ECU up under the glove box as well again.

I am thinking of next switching into 4hi and turning truck off to confirm that transfer case acuator is actually switching to 4hi.

Anyhow I will keep you all posted if anyone has any tips please pass they would be appreciated.

Thanks,
JTO

 

I am anxiously awaiting your results. I also am having issues with my 4wd actuators. I pulled both high and low actuators off and tested both. Both seem fine, they actually look brand new. My 4HI light flashes constantly, even though Im in 2wd. Light will not go off, nor will it go into 4wd.

 

Switch problem????

 

It might be the switch, or the little computer behind the glove box. Today I removed both actuators again and made sure the gears and contacts were both in the correct positions. At least the 4HI lights doesnt flash anymore while in 2wd, but my 4wd still does not work. I guess my next step is to check the wiring. Anyone know where I can find a wiring diagram showing the switch, ECU, and actuators?

 

Just a update here guys.
I finally got my 4hi problem fixed.
2wd to 4hi to 4lo to 4hi to 2wd working again.

I had a bad Front A.D.D actuator and something was wrong with my transfer case actuator 4HI upper modules as well.

I will tell you make dammed sure you put the planetary gear and all back in super tight and seated correctly or the gray 4x4 indicator switch will not be set off when the arm comes around to signal you are in 4hi at the Transfer case. You will chase your tail for hours.
I battled this problem for about 8-10 hours and taking the top actuator mode off about 20x.

I will post some pictures next week.

Thanks for everyone's input much appreciated.


JTO

 

Also when you take the actuator module off before really careful not to break the 4x4 signal switch (grey).
I did this on my new $540 part and had to use the switch of my old part. PITA.

Thanks,
JTO

 

Hi All! I'm a new member and this is my first post. I'm really writing to thank you all for the excellent information on this post, and to suggest that anyone with actuator problems in a Sequoia take a few minutes to read this post before opening your actuator motor.

BACKGROUND STORY: I had an '03 sequoia with 193,000 miles. Absolutely everything worked, but I ran into the deadly frame rot and I'm outside the 12 year timeline on frame replacement. Started looking for a new vehicle and I came across an '06 Sequoia with 139,000. The price was too high, but when I test drove it I found out that it wouldn't go into low. The dealer said that it required opening the transfer case and quoted $2600. I did some research on your page and thought that there was about a 70% chance that I could fix it myself. I took a huge gamble, took the $2600 discount on the price of the vehicle, and bought the '06.

REPAIR: Last night I attempted to work on the repair. That's when I had the 'uh oh' moment when I discovered that my actuator motor on the '06 Sequoia looks different from everything I've found here on the Tundra site (my '03 was a perfect match). I took a chance and opened the unit. it was very difficult do and I stressed the plastic to near breaking point (there was a knob on the transfer case that was in the way and it was difficult to get around). My hose was still in tact and the inside of the unit was immaculate, which is different from some others experiences. Thanks to the excellent posts above from sixweeds, I was able to line up all of the gears and get it back together, but it was tricky. After getting everything back together the vehicle worked exactly as it did before. I didn't fix the problem, but at least I didn't break the truck.

LAST DITCH EFFORT: I was parking the vehicle after the test drive when I remembered one of the posts on this site talking about needing to work the kinks out of a rusty motor. I also realized that there was one section of grease on one of the gears inside my unit that had gotten really hard. I think that the previous owners used 2HI and 4HI, but not 4LO and the gears never ran through that section of grease, letting it get hard. I sat in the driveway for a full 20 minutes with the truck running and the transmission in neutral. I'd push the 2HI button/4HI button, then 4LO button, then reverse the process. The car could shift from 2HI into 4HI, but not into 4LO. The 4LO light would flash but never complete the shift. After 20 minutes I was going to give up when I realized it was taking longer for the 4LO button to stop flashing, meaning that it was making progress. That gave me hope and I kept at it, figuring that the gear was working it's way through the thick, hardened grease. It eventually made it all the way and started working. I'm not sure how long it took, but the patience paid off. I took it for a test drive and everything works perfectly!

CONCLUSION: I'm grateful for all of the insight and understanding that I gained from this site. It saved me $2600. I do wish that I had tried to work out the system before opening up the unit! If someone is having difficulty with their actuator and the vacuum hose to the unit is intact, it might be worth sitting in your vehicle for 20 minutes patiently running the system through it's paces before taking things apart.

 

Guys, back in October of 2019 I was on a hunting trip here in Colorado. I was driving up a steep narrow mountain road about 1/2 mile up and came across a tree that fell across the road. I decided to put into 4lo to back down the road. Well like an idiot I went straight from 2hi to 4Lo. I was in neutral and before I knew it I lost all gears. Park, reverse and drive. I had to coast down the hill to leval ground. I pulled the two actuators on the transfer case and manually pushed both rods all the way in. Regained all gears and was able to drive home.

I didn't have any codes or lights flashing at me until I went to 4hi then I would get that damn flashing 4hi light. After many attempts of setting the timing on the 4hi actuator (like 30times) I finally got 4hi to stop flashing and it did engage in the transfer case. I put all the screws in and tightend them all. Dropped the truck and went for a drive down a dirt road switched to 4hi and the damn flashing 4hi light came back

Came back home set it on jack stands and decided to try something that I thought back at the beginning of trying to set timing.

I removed the 4hi actuator switced the ignition on, set transmission to neutral and put it in 4hi once I heard the actuator move I switched the ignition to off. Then I proceeded to pull the 4hi rod all the way out to manually set the transfer case in to 4hi. It was a little stiff I also had to rotate the rear drive shaft to accomplish this. I then checked the front drive shaft and confirmed the 4hi. Then I installed the 4hi actuator tightly. Turned on the ignition and switched to 2hi and light went off then switched to 4hi and I heard the 4hi actuator rotate and then the front differential actuator rotate and a solid 4hi light . Dropped the truck and took for test drive and all worked as it should

All of my actuators were in like new condition I did pull the front diff actuator off to inspect thinking that it was not functioning properly. It was so I reinstalled with the toyota gasket making stuff let cure and refilled the diff with 75w90 diff fluid.

Sorry for the long post I thought maybe a little background might help someone.

 

Thank u to all the people that have posted amazing info on this forum. I have a 2011 tundra and the 4LO light started blinking for a few days then one day it turned off and I went to cycle my truck through 4HI and 4LO thinking that something just got stuck...well it went into 4HI then would not come out. I turned the truck off then back on and it went right back to just the 4LO light blinking. Took it to a shop and they said they had no communication with the transfer case and that I would have to take it to the dealership. Of course the dealership said they would charge $4,300 for a new actuator becuase you have to drop the transfer case becuase they refuse to just leave the actuator rods in and assemble new parts onto the existing actuator housing. So I drove my truck home (still stuck in 4HI) and I cringe every time I make a tight turn becuase i can feel the transfer case binding up. I take apart the actuator housing and from what I have see I think that the position sensor on my 4LO actuator has broken off. I don’t know how becuase I didn’t see it fall out but it is no longer there. I put the actuator back onto the assembly and turned my truck on and shifted out of neutral to park and I heard a horrific grinding noise and turned the truck off immediately. I took it back apart with the actuator still connected to the wiring harness but not on the housing. and turned on the truck and the 4HI motor will rotate to a position but the 4LO motor will not move at all. Once the truck is on and I move the switch from 2wd to 4wd still no movement from either of the actuators. My thought process is that it is trying to communicate with the 4LO actuator to figure out what position it is in but can’t becuase the switch is broken and that is causing the computer to freak out and not want to shift from 2wd to 4wd. I am currently trying to get a new actuator from a salvage yard so I can pay $250 instead of $500 hoping that it is the position switch that I believe is missing on the 4LO actuator. Even once the 4HI actuator spins to whatever position it thinks it is suppose to be in and I install back onto the housing. When I turn the truck on and try to shift into gear it still makes the horrific grinding noise that is scaring me lol. Really trying to not shred my entire transfer case apart. When I installed the actuators back onto the housing the rods within are what I believe to be the disengaged positions slid as far as they can into the transfer case but they still stick out into the housing about half way. Are they suppose to go in more than that? And any ideas on what the horrific noise is and how I could fix it?

 

Tip for anyone having trouble getting 4Hi to engage after figuring out the timing: I used the tricks and pics in this thread to confirm the correct timing (turn on 4Hi with the motor/gears plugged in, but not installed in housing). But, after installing, my truck would attempt to engage 4Hi (slow blink) and then after about 10 seconds it would fail to engage and go to a fast blink. After much trial and error, I figured out that I wasn't getting the necessary inward tension on the rod, so that when 4Hi was engaged, the rod would hit the back of the housing before the switch was engaged. So, I got the system to tension the rod for me by offsetting the gear just a bit (maybe 1/4-1/2 inch), so that when I turned the truck on and it automatically positioned the gear it would apply the inward tension. Example pictures attached, but note I mocked these up using the old parts after I got my truck fixed, so I can't say they're exactly what I did, but close enough to give you the idea.

 

Lots of great information in this thread!

But sadly, I have been unable to resolve my flashing 4HI light issue.

2012 Tundra, 5.7 V8, Auto.

My 4x4 engagement was intermittent when I first got the truck a few months ago.
It also had noisy transfer case bearings, so I pulled the TC and replaced the bearings. I opened up the actuators, while on the bench, and everything appeared OK.
Using the info in the this thread, I was convinced that I had everything timed correctly.
So I re-installed the TC, and now have the flashing 4HI issue.
I have tried the pulling the actuator covers and turn ignition on, replacing covers, at least 20 times, and still no improvement.
Downloaded factory service manual, went through many pages of testing the harness, switch, voltages, resistances, all OK.
Next I looked at front A.D.D., as I wasn't hearing it activate. Pulled it, set up a relay for bench test, no response. Bought a new unit, still have flashing 4Hi, hear actuator, but not always, sometimes nothing at all.
I have reset the 4x4 modules many times as well, and have cleared DTC's.

With actuator covers off, I can manually move into 4HI or select 4LO, so I am confident that the transfer case was correctly re-assembled.

I am close to scrapping the whole electronic system and finding a kit to make it a manual shift TC, but that will take some switches and relays, unless I make the ADD manual as well.

 

Smiffy, did you need to open up the actuators or were just curious about their condition? I have (what i think) is a bad bearing in my TC. At about 20 mph in 4wd it starts to make a noise, like something is rubbing. I picked up a used TC for $200 bucks from a junkyard but it's whole life has been spent up north while mine looks like the day it came off the factory floor. I figured I would pull it apart and figure out which bearing is bad and replace it and keep the other as a spare.

 

I opened up actuators, to see if the contacts in lids were burnt or worn, as I had intermittent 4x4 engagement. I buffed up the contacts with 600 sandpaper, as there were some black areas.

I would put your truck up on 4 sturdy stands, and get under it with a stethoscope, while your buddy "drives" the vehicle. Bearing noises can be very difficult to locate from the driving seat. Try in 2wd, then 4wd, then try disconnecting front drives shaft from the transfer case( tie it away from drive flange on TC). That's how I diagnosed my bad bearings. I also dropped the rear driveshaft, from the TC to eliminate shaft/ U-joint issues.

Changing the TC case bearings wasn't too hard. Let me know if you need any help.

 

I'm just being lazy, lol. I have a 2 post lift and have done some testing but the noise only happens under load. With all 4 tires off the ground or with the front driveshaft removed it's quiet. I had thought it could be the chain inside the TC or a bearing. You can't buy the chain, which is why I picked up a low mileage spare. I just need to break down and fix it. The other problem is my torque converter is one that was never replaced under a factory recall and the clutch isn't engaging/ disengaging smoothly. So when I do the transfer case I'll end up doing the torque converter at the same time. It's too cold now so it'll wait until spring.

 

Hey everyone, truck is in 2wd blinking 4hi and the upper/lower motors are removed. Both threaded rods going into the tcase are not budging + front driveshaft is not moving, am I stuck in some weird half/4x4 engage?

 

Reviving an old thread for some input. I have recently changed out my 4hi actuator and finally (I think) got the timing right but here is my issue:
I can get 4hi/low to work every time but ONLY when my truck is cold (i.e. first thing in the am or when it sits for a few hours). After driving for about 10-15 min, it won't go into 4hi. I hear the actuator "activate" when I switch to 4hi but i get the 4hi blink. I saw on a previous diagram that there is a "actuator temperature sensor". Not sure if that has anything to do with the issue or if anyone has any other ideas as to what could be causing this and how to trouble shoot it. Thanks in advance.

 

Question regarding the transfer case rod positions. I think there are two pods going into the transfer case and each rod has two valid positions, pushed in and pulled out, for 2008 tundra. My question is what positions do the rods need to be in for the truck to be in 2wheel drive. Also, my current issue is that the truck is stuck in 4h, which side of the actuator should I open up? I think the actuator has two sides, one for each of the transfer case rods.