Transfer Case Tuneup and Fix (7 Viewers)

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Some folks have been able to R&R these motors. Some have found they're in bad shape and need to replace the whole actuator. The beginning of this thread shows how to pull the external motors off and clean them up.

Actuating 4Lo and the CDL can help, but for slightly different reasons than some people think. It has nothing to do with the transfer case internals engaging or the diff fluid... engaging the mechanisms causes the externally mounted motor to spin which pushes the rod into the transfer case to engage it. There are metal contacts and switches and the activation can essentially help "remove" very minor corrosion - particularly the semi-circle metal contacts.

Nobody is 100% sure why we get the fast flashing CDL light, but because it happens instantly at startup I highly suspect it's because something inside the motor isn't making good contact (or is making contact where it shouldn't, or simply is seeing the motor in an invalid position) and the flashing CDL is the systems way to deactivating the motor to avoid damage. It's always been odd to me that driving for about 5 minutes and then restarting the truck seems to clear it for most people as the external motor isn't being exercised or lubricated like the internal transfer case components. Maybe it's a bit of heat coming off the exhaust or warmth from the transfer case or warm air flowing out the breather that makes things function?

You can also see the above "fast flash" issue if you push the CDL button, particularly when the vehicle is cold. If the CDL flashes slowly that means it's trying to engage and in that case driving and/or turning a bit will usually cause it to lock in as the CDL doesn't want to lock unless the front and rear shafts are spinning at the same speed (50/50). It's why finding a gravel parking lot and doing figure 8's will help - if there's a bit of binding, which could even be because your front and rear tires are slightly differently sized due to wear, then your transfer case might be splitting power 49/51 and so turning slightly will alter the ratio just enough to engage.
Linuxgod, I see the same from reading up on this and watching the online videos. Makes sense after driving and heat and/or vibration and alternator voltage on the system (~14.5 vs 12.5 battery) that things can clear.

Some things to consider as part of longterm maintenance:
- Checking and as required replacing the TC vent line to prevent water ingress, key for the transfer case internals and possible prevention of water ingress into the actuator (having to pass the seal which during actuation seems possible by low viscosity (1cP) water). This is where TC oil replacement can also be your friend. The Ravenol package for LC200 Diffs and TC is not that expensive so that is one good route so it seems.
- Opening up the actuator at say 100k intervals and reapplying dielectric grease. When doing lots of water crossings potentially at shorter intervals.

Is this really needed? Maybe not when all keeps working right. Would it be worth doing when you do not mind wrenching a bit? I would think so.
 
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Linuxgod, I see the same from reading up on this and watching the online videos. Makes sense after driving and heat and/or vibration and alternator voltage on the system (~14.5 vs 12.5 battery) that things can clear.

Some things to consider as part of longterm maintenance:
- Checking and as required replacing the TC vent line to prevent water ingress, key for the transfer case internals and possible prevention of water ingress into the actuator (having to pass the seal which during actuation seems possible by low viscosity (1cP) water). This is where TC oil replacement can also be your friend. The Ravenol package for LC200 Diffs and TC is not that expensive so that is one good route so it seems.
- Opening up the actuator at say 100k intervals and reapplying dielectric grease. When doing lots of water crossings potentially at shorter intervals.

Is this really needed? Maybe not when all keeps working right. Would it be worth doing when you do not mind wrenching a bit? I would think so.
Mine didn’t have any signs of moisture or any visible corrosion, FWIW
 
EDIT: I FOUND IT. Rod should be pushed all the way in or close to it. Just had to change the words used in the search.

Hey guys! So I started having problems with the diff lock flashing upon startup. I've been using it at the beach a lot this summer. I can only guess that the previous owner never used it, so now that I am, it started acting up. I took it apart as detailed in this thread and videos. Took note of the clocking of the gears but I don't believe they are correct. I believe this to be the case because when pressing the diff lock button to engage, there's a much longer whirring sound as it engages, but to disengage, it whirrs for only maybe half that time, a split second and then starts flashing the light on the dash.

Anyways, mine is actually quite clean inside though the grease does look old and brown in spots where I suppose it just 'sat' as it was never actuated.

Ok, here's my question, I want to reset things. I want to start with diff lock disengaged, so is that with the rod all the way in or all the way out? In all the videos, I see them mainly working on the hi/lo side of things and shows the rod should be all the way into the t-case. Is the diff lock the opposite? Because mine was all the way out into the plastic casing. When I put the truck in N and pushed it back a bit, I was able to push the rod all the way in. Just need to know that aspect when putting it back together, as well as the clocking of the gears. Here is an image of mine as it sits currently, before I take it apart to clean up the traces inside.

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20240710_172406.jpg


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Ya have similar inhibitions - I got my new diff actuator a few weeks ago but unsure about which it is set to out of the box. Full replacement is pretty involved with the diff drop and all 🤢
 
Hey guys! So I started having problems with the diff lock flashing upon startup. I've been using it at thr beach a lot this summer. I can o ly guess that the previous owner never used it, so bow that I am, it started acting up. I took it apart as detailed in this thread and videos. Took note of the clocking of the gears but I don't believe they are correct. I believe this to be the case because when pressing g the diff lock button to engage, there's a much longer whirring sound as it engages, but to disengage, it whirrs for only maybe half that time, a split second and then starts flashing the light on the dash.

Anyways, mine is actually quite clean inside though the grease does look old and brown in spots where I suppose it just 'sat' as it was never actuated.

Ok, here's my question, I want to reset things. I want to start with diff lock disengaged, so is that with the rod all the way in or all the way out? In all the videos, I see them mai ly working on the hi/lo side of things and shows the rod should be all the way into the t-case. Is the diff lock the opposite? Because mine was all the way out I to the plastic casing. When I put the truck in N and pushed it back a bit, I was able to push the rod all the way in. Just need to know that aspect when putting it back together, as well as the clocking of the gears. Here is an image of mine as it says currently, before I take it apart to clean up the traces inside.

View attachment 3674567
That bit of detail is definitely covered in this thread, or the other one about this issue. I may have even posted it, but can't point you to it while on a phone. If you don't find by tomorrow, I'll be able to look while not browsing from a potato.
 
That bit of detail is definitely covered in this thread, or the other one about this issue. I may have even posted it, but can't point you to it while on a phone. If you don't find by tomorrow, I'll be able to look while not browsing from a potato.

EDIT: I FOUND IT. Just has to change the words used.
I'm pretty good at searching. I searched the thread but was unable to find a post specifically talking about. Apologies. I'll go take another look. I read through 10 pages....lol...perhaps I missed the one page it was discussed.
 
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Ya have similar inhibitions - I got my new diff actuator a few weeks ago but unsure about which it is set to out of the box. Full replacement is pretty involved with the diff drop and all 🤢
Gawd, tell me you got a used one and didn’t pay for a brand new one!? 😬😬
 
EDIT: I FOUND IT. Rod should be pushed all the way in or close to it. Just had to change the words used in the search.

Hey guys! So I started having problems with the diff lock flashing upon startup. I've been using it at the beach a lot this summer. I can only guess that the previous owner never used it, so now that I am, it started acting up. I took it apart as detailed in this thread and videos. Took note of the clocking of the gears but I don't believe they are correct. I believe this to be the case because when pressing the diff lock button to engage, there's a much longer whirring sound as it engages, but to disengage, it whirrs for only maybe half that time, a split second and then starts flashing the light on the dash.

Anyways, mine is actually quite clean inside though the grease does look old and brown in spots where I suppose it just 'sat' as it was never actuated.

Ok, here's my question, I want to reset things. I want to start with diff lock disengaged, so is that with the rod all the way in or all the way out? In all the videos, I see them mainly working on the hi/lo side of things and shows the rod should be all the way into the t-case. Is the diff lock the opposite? Because mine was all the way out into the plastic casing. When I put the truck in N and pushed it back a bit, I was able to push the rod all the way in. Just need to know that aspect when putting it back together, as well as the clocking of the gears. Here is an image of mine as it sits currently, before I take it apart to clean up the traces inside.

View attachment 3674567

View attachment 3674577

View attachment 3674578
Those contacts look mighty corroded,but your motor looks freaking MINT! 👍 check your breather hoses too to make sure they aren’t letting any beach water in. I’d say a clean off of the contacts and a re grease and check of your solder points and you’re good to go!!
 
Those contacts look mighty corroded,but your motor looks freaking MINT! 👍 check your breather hoses too to make sure they aren’t letting any beach water in. I’d say a clean off of the contacts and a re grease and check of your solder points and you’re good to go!!

Yeah just got the clocking right, like in the video (image). I cleaned it all out and it looks great (images). Gonna take it apart to regrease with white lithium by sta-lube. Then go reinstall.

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I am delighted to see more people tackle this fix, and that others can sweat many fewer bullets over it.

The CDL/4Lo actuator is now the recirc damper flap of the transfer case.

For real! You just reminded me that the passenger side vents are slow to change temp, which if I'm not mistaking is the airmix/blend door servo for the passenger side. Thankfully, the 4lo works just fine so hopefully I don't have to mess with that one anytime soon.
 
Yup- push the rods into the T-case after you clock the actuator gears correctly.
 
I am delighted to see more people tackle this fix, and that others can sweat many fewer bullets over it.

The CDL/4Lo actuator is now the recirc damper flap of the transfer case.
Thanks for reminding me that I’ve yet to tackle the recirc damper flap….anyone have any pointers on how to fix that one!? It’s on the list of needs…🙄😂
 
FWIW, you did a hell of a lot better job cleaning yours than I did mine, but mine has worked flawless for almost two years now. 👍👍

Thanks! It won't work though 😞
I have the gear clocking almost perfect....I think. However, as soon as I start the truck, I can hear the actuator actuate, and ENGAGE the locker. I then have to press the button, it starts to unlock, will blink slowly, but will go off if I put it in reverse and back up a tad. If I shut it off, then start it again, it does the same thing. Why is it trying to actuate it on startup? I have the rod all the way into the tcase. If I leave it blinking, and turn it off, go under the truck to pull the actuator off again, there's tension in the spring and the rod is pushed in to the actuator housing, locking the diff.

I'm not entirely sure what I'm doing wrong. I saw another video that has the guy lining up the three prongs on the bottom of the gear, with the three dots on circular leads. If I do that, the clocking looks a bit off. I tried it, and it seemed worse, wouldn't engage at all. Just blinking diff lock light 🥴
 
Thanks! It won't work though 😞
I have the gear clocking almost perfect....I think. However, as soon as I start the truck, I can hear the actuator actuate, and ENGAGE the locker. I then have to press the button, it starts to unlock, will blink slowly, but will go off if I put it in reverse and back up a tad. If I shut it off, then start it again, it does the same thing. Why is it trying to actuate it on startup? I have the rod all the way into the tcase. If I leave it blinking, and turn it off, go under the truck to pull the actuator off again, there's tension in the spring and the rod is pushed in to the actuator housing, locking the diff.

I'm not entirely sure what I'm doing wrong. I saw another video that has the guy lining up the three prongs on the bottom of the gear, with the three dots on circular leads. If I do that, the clocking looks a bit off. I tried it, and it seemed worse, wouldn't engage at all. Just blinking diff lock light 🥴
those three dots, iirc, are divots from wear. If those guys don't make good contact, then the system will misbehave. There's a video of a guy in a shop in Malaysia (I think) where he drops some solder into the divots and sands them back down to the level of the contact rings. Before you mess with that, however, make sure you rule out the clocking as an issue, since that is much less annoying than going the solder route. FWIW, mine had divots; I cleaned them well and did not solder.
 
those three dots, iirc, are divots from wear. If those guys don't make good contact, then the system will misbehave. There's a video of a guy in a shop in Malaysia (I think) where he drops some solder into the divots and sands them back down to the level of the contact rings. Before you mess with that, however, make sure you rule out the clocking as an issue, since that is much less annoying than going the solder route. FWIW, mine had divots; I cleaned them well and did not solder.

Oh ok. I thought they were some sort of alignment marks. You can see the pictures above of mine after I cleaned it. Can't get it any cleaner than that. I'm 99.9999% sure I'm aligning it right. Doing it just like in the video. I did see that other one a few days ago where the guy soldered the paths and sanded them down. I'm THIS close to just ordering a replacement and trying the whole swap instead. Could this be associated in any way to the micro switch? What's its purpose? Mine doesn't click or anything. It just pushes in and bounces back with no real resistance or noise. There's also the sensor on the other end I assume is some sort of hall effect/magnetic sensor.
 
Thanks! It won't work though 😞
I have the gear clocking almost perfect....I think. However, as soon as I start the truck, I can hear the actuator actuate, and ENGAGE the locker. I then have to press the button, it starts to unlock, will blink slowly, but will go off if I put it in reverse and back up a tad. If I shut it off, then start it again, it does the same thing. Why is it trying to actuate it on startup? I have the rod all the way into the tcase. If I leave it blinking, and turn it off, go under the truck to pull the actuator off again, there's tension in the spring and the rod is pushed in to the actuator housing, locking the diff.

I'm not entirely sure what I'm doing wrong. I saw another video that has the guy lining up the three prongs on the bottom of the gear, with the three dots on circular leads. If I do that, the clocking looks a bit off. I tried it, and it seemed worse, wouldn't engage at all. Just blinking diff lock light 🥴
I unplugged my module after hooking everything up and disconnected my battery too in an effort to clear any fault codes.

Check out in this video where to find it. It’s on the passenger side kick panel. Do you hear any clicking coming from there when you engage. It sounds like you’re close. I was in the same boat fighting it for about three days.

Toyota Flashing 4-Hi/4-Lo & Center Differential Light Troubleshoot and Repair #toyotasequoia
 
I unplugged my module after hooking everything up and disconnected my battery too in an effort to clear any fault codes.

Check out in this video where to find it. It’s on the passenger side kick panel. Do you hear any clicking coming from there when you engage. It sounds like you’re close. I was in the same boat fighting it for about three days.

Toyota Flashing 4-Hi/4-Lo & Center Differential Light Troubleshoot and Repair #toyotasequoia


I'll check it out. I did some troubleshooting the last few hours. One thing was to disconnect the battery and hook it all back up. That didn't do anything (I waited like half an hour for the controllers/modules to all fully lose power and reset). Nada.

However, I think I made some progress. Here's what I found. I disassembled the cdl and hooked it all back up, leaving it sitting upside down on the housing, but left the guts out in order to test the button. This immediately gave me a quickly flashing diff lock light and it would not even try to actuate. So, I suppose not having the prongs making contact with the pathways breaks the connection. Next, I put the the gears back in and clocked it. As soon as I powered it on it actuated the gear freely and had a solid diff lock light on the dash. I then pressed the button to disengage and it did so, but the light started to slowly flash like it was doing before, keep in mind, its not actually assembled and actuating the rod, its just sitting there in the open air. I was expecting to see it stopped in a different orientation when I got back under the vehicle, only to find it had stopped at exactly the same spot we all clock it to when reinstalling. I tried a few more times. I'd get a nice solid light indictating locked, then blinking light every time I unlocked it. It stopped every time in the same exact spot.

Now I don't k ow if that's it's "parked" position, but I would assume so. This leads me to believe that those divots are indeed likely the cause here...? It's losing the connecrion/voltage when it hits those divots, and erring out? It's weird that when it's assembled like normal, the light would stop blinking and go out if I reversed the truck a bit. Maybe the rod moves just enough at that point to push the gear into a part of the pathways that makes contact and it it acknowledges the fact that it's in the disengaged position?
 
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Would mounting a winch possibly decrease voltage and impact 4Lo engagement? Today was the first day I hit a trail after the winch was installed and CDL engaged easily however 4Lo refused to engage.

I hit a couple of trails just three weeks ago, before dropping it off for the winch and other work. The only thing I can think of is the winch and voltage after reading voltage matters.
 

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