Transfer Case Actuator Failure (1 Viewer)

[Anton Taljaard]

Now on my 3rd transfer case actuator failure in less that 4 years. I finally managed to confirm that it's due to water and contaminants (lots) entering the actuator somehow. Other threads here indicted that breather line could be the cause and found it was somewhat perished.

My question though is could this amount of water & gunk have entered through the breather alone and if not, where could this be coming from. I have never waded through any deep water with the verhicle and only wet driving ever done was though rain and normal size puddles.

 

[bloc]

I’d be curious what the other end of the breather hose looks like… the trouble is it’s really tough to get to, on top of the transmission bell housing if I remember correctly.

 

[Anton Taljaard]

I’d be curious what the other end of the breather hose looks like… the trouble is it’s really tough to get to, on top of the transmission bell housing if I remember correctly.

That was my next port of call. Haven't unfortunately not been able to find any technical diagrams for where the breather hose exactly runs and originates. Unfortunately the agents aren't exactly showing much enthusiasm in fault finding beyond what the diagnostics indicate.

 

[cnckrtcruzr]

Now on my 3rd transfer case actuator failure in less that 4 years. I finally managed to confirm that it's due to water and contaminants (lots) entering the actuator somehow. Other threads here indicted that breather line could be the cause and found it was somewhat perished.

My question though is could this amount of water & gunk have entered through the breather alone and if not, where could this be coming from. I have never waded through any deep water with the verhicle and only wet driving ever done was though rain and normal size puddles.

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How hard is it to actually just replace the actuator. Mine will not engage into 4 Lo.

 

[Anton Taljaard]

How hard is it to actually just replace the actuator. Mine will not engage into 4 Lo.

Replacing the actuator requires the full removal of the transfer box so not al that easy.

That said it is possible the replace the electronic components of the actuator without removing it from the transfer box.

 

[linuxgod]

How hard is it to actually just replace the actuator. Mine will not engage into 4 Lo.

It was easy, I just wrote the dealership a check for $2600

Seriously though, it's a 5-6 hour job for a trained mechanic to drop the transfer case and swap the actuator. Unfortunately you have to open the transfer case to swap the entire thing as the rods are retained in the T-case with C clips.

If the inside of your T-case is fine the external actuator motors can come off and be swapped in an hour or two. Doing that leaves the rods in place. The primary challenges for doing this are (a) there's a specific way you have to "clock" the motor position when reinstalling, and (b) the center diff actuator sits on top so you need to hold it in place with a putty blade when you reinstall it or it'll fall apart as you flip it over and you'll have to try again.

 

[linuxgod]

Now on my 3rd transfer case actuator failure in less that 4 years. I finally managed to confirm that it's due to water and contaminants (lots) entering the actuator somehow. Other threads here indicted that breather line could be the cause and found it was somewhat perished.

My question though is could this amount of water & gunk have entered through the breather alone and if not, where could this be coming from. I have never waded through any deep water with the verhicle and only wet driving ever done was though rain and normal size puddles.

Did you replace the entire actuator assembly previously or just the motors? Were they like this or just rusty previously? Did 4Lo and the CDL both not work previously or was it just the CDL?

There are only 3 ways I'm aware of for water to enter that housing.

1. through the breather tube entry point on top of the CDL actuator motor
2. through the seal between the main actuator housing and the actuator motor or a crack in the actuator housing itself
3. secondarily through the transfer case itself, as the T-case vents into the CDL actuator. (I didn't think it vented into the 4WD actuator motor though)

Your actuator motor looks terrible. I've seen some rusty motors which obviously had moisture intrusion, but that's a soupy mess. You wouldn't necessarily need to ford a river to get that kind of mess in the top (CDL) actuator motor - if the breather tube had come off or just had a big split then you'd have a fine mist of rain water constantly being sprayed across that breather spot and allowing water and road dirt to seep in over thousands of miles. The pics definitely look like there's water involved... I can't tell if the rest is just oil or dirt or both?

It looks like both actuators CDL (top) and 4Lo (bottom) are a mess which means whatever moisture was entering most likely made its way into the transfer case too, so you should definitely change the fluid in the T-case.

Honestly with that mess I'd want to drop the transfer case to do a full inspection. I don't think the transfer case vents into the 4WD actuator motor housing... if it does then yes it could just be a bad or disconnected breather tube letting moisture in and enough water migrates through to the transfer case and then the lower 4Lo actuator motor housing. But it could also be a crack in your housing or something else letting moisture in. And if there's been water in the transfer case for a while, personally I'd want to open it up and make sure it's all cleaned out and try to inspect everything for rust or significant wear before replacing the t-case oil.

Once you're done I'd run a new breather tube from the CDL actuator motor vent all the way up to the firewall and replace the breather vent at the top. I don't have a pic handy but I believe the t-case breather is somewhere on the firewall just below or behind the master cylinder, however you could run a new line to anywhere you want so long as it's near the top of the engine bay. Just make sure you get a Toyota one-way breather vent for the top of it so hot air can escape but moisture can't get in.

 

[cnckrtcruzr]

It was easy, I just wrote the dealership a check for $2600

Seriously though, it's a 5-6 hour job for a trained mechanic to drop the transfer case and swap the actuator. Unfortunately you have to open the transfer case to swap the entire thing as the rods are retained in the T-case with C clips.

If the inside of your T-case is fine the external actuator motors can come off and be swapped in an hour or two. Doing that leaves the rods in place. The primary challenges for doing this are (a) there's a specific way you have to "clock" the motor position when reinstalling, and (b) the center diff actuator sits on top so you need to hold it in place with a putty blade when you reinstall it or it'll fall apart as you flip it over and you'll have to try again.

lol sounds easy enough just need to reach for the wallet! I appreciate the quick reply!

 

[Anton Taljaard]

Appreciate the reply,

So the full actuator assembly was replaced both times (I unfortunately never saw the first failed unit myself) and not just the motor units. The second one I have in my possession and have seen the new unit on the car myself. That obviously required the TK to be dropped. On both occasions there was no water present inside the TK and everything inside was found to be in proper working order.

This last time around after having no real feedback from my Toyota dealer /agent regarding the possible causes I took the vehicle to a gearbox specialist whom, after dropping and opening up the TK confirmed that it had no defects ie no water found inside either.

The gunk inside the actuator unit was definitely water, particals of fine dust and grease. You're correct in that it was both CDL & 4LO that was contaminated. Initially the car would not engage CDL only but then progressed to 4LO light flashing intermittently. Finally the car just wouldn't go into gear when shifting into D or R.

I'll be replacing the CDL breather vent line as per your suggestion next. Also thinking of doing periodic inspection of the motor units to see if any moisture might have gotten inside again.

Thank you again for the advise.

 

[linuxgod]

lol sounds easy enough just need to reach for the wallet! I appreciate the quick reply!

I tried to do the work first myself. I messed up the microswitch in the CDL when trying to reinstall it. If I did it again I wouldn't remove that switch and clean it. Lesson learned. So not, not exactly "easy" to do but once I ran into problems I had limited time to fix it and decided it was the smartest course of action for me

 

[cnckrtcruzr]

I tried to do the work first myself. I messed up the microswitch in the CDL when trying to reinstall it. If I did it again I wouldn't remove that switch and clean it. Lesson learned. So not, not exactly "easy" to do but once I ran into problems I had limited time to fix it and decided it was the smartest course of action for me

Is it worth fixing if off roading is not going to be done very much? If it is done it would be probably Florida beach off roading nothing really heavy.

 

[linuxgod]

Is it worth fixing if off roading is not going to be done very much? If it is done it would be probably Florida beach off roading nothing really heavy.

At some point the CDL light will flash every time you start the truck, and you’ll be unable to use 4Lo and the CDL at all. That might not matter to you but the flashing CDL may have other impacts on traction control and the ability for the center diff to properly vary power output. Or not. But you can certainly wait until it gets bad enough

 

[cnckrtcruzr]

At some point the CDL light will flash every time you start the truck, and you’ll be unable to use 4Lo and the CDL at all. That might not matter to you but the flashing CDL may have other impacts on traction control and the ability for the center diff to properly vary power output. Or not. But you can certainly wait until it gets bad enough

Oh yea that makes sense and a flashing cdl would bother the hell out of me. Anyone have any idea where I may be able to find the electronic portion of the actuator? My guess is that is the point of failure and not the rods

 

[linuxgod]

Oh yea that makes sense and a flashing cdl would bother the hell out of me. Anyone have any idea where I may be able to find the electronic portion of the actuator? My guess is that is the point of failure and not the rods

There’s a thread on how to R&R the actuator motors.

Nobody is positive the underlying issue but cleaning up the contacts, using new grease, and using CRC on the motors seems to resolve the issue for a lot of people. The general consensus is that a bit of corrosion happens and the resistance is too high or the voltage too low at vehicle startup. I’m a bit suspect of that purely being the problem since the issue seems to stick around for 5-10 min until the transfer case starts to warm up a bit.