Cheap A.D.D fix. Flashing 4wd light/water issue please read!

[FAIL]

Another big thank you! I'll post some pics of my before and after but you made it super easy to do!

[Zeussy]

Also like to add onto this, I changed out my electric motor a little while ago, and all was well - went 4WDing a few times after it and 4WD was working fine, but since haven't used 4WD for a few weeks and when I tried to use it briefly at work last week noticed it came up with the little flashing icon on the dash again.. Although it seemed like 4H was engaging, it wouldn't let me engage 4L or diff lock.

With a bit of mucking around, checking the unit was timed correctly and the gears were spinning freely etc I checked out the little micro switch with a multimeter, and found it to be faulty. So I just carefully popped the little cover off it and removed the contact which was pretty severely corroded. Cleaned the contacts inside the base of the switch as best I could and reinstalled with some grease to prevent future corrosion..

I'd recommend to anyone that has had water in there ADD units to flick the cover off that micro switch and clean and re-grease with a suitable electrical grease. Even if it's still working currently, it's a good measure to prevent future problems.

[leghorn]

would have been cheaper to fit a front locker than to replace the unit with another from toyota

[scratcher]

For all the guys that had to fix this problem, how'd the water get in in the first place? I'm thinking prevention is better than cure so looking to avoid ever needing the fix

[Jrp131191]

Hi everyone, I copped the 4wd light flashing in orange after ~30 mins of driving problem a while back.

I noticed today that the ADD breather hose was not connected. I'm still learning the ins and outs of the 4by world but by the looks of it, even if I stretched the hose out to the point of tearing it, it would still not reach what I assume is where it needs to connect to. Could this be because the previous owner installed a diff drop and didn't extend the hose?

Is this where the hose is supposed to be hooked into? It's a hollow metal piece with hose hooked onto the other end but nothing on that end. The metal piece is attached to what I also think is the front diff breather hose.

https://ibb.co/cJMGvCy

Does anyone know where I can source some more of this hose or if I would just be better off purchasing a breather kit such as the AOB one?

TIA!

[Balsan]

After 3 years I have found the root cause of my ADD malfunctioning.

The solution is very simple to prevent this.

The cause is moist getting inside the ADD.

Check to do: viewing from under the vehicle, you cannot see that the ADD has a small hose on top of it, this hose in my case (European Hilux Revo) sits at the right side of the engine under the bonnet, however is sits approximately 50-60 cm above the ground floor. Since there is NO breather on it, occasionally when drive through serious water, water comes in the hose.

How did i Fix it?
Simply punt in some fuel line hose into the hose (fits perfectly), and extend the hose way up high under the bonnet, and then bend it back downways to create a gooseneck. Now it is impossible for any water to ever get in there.

I suggest all Toyota owners with an ADD to check this hose, since it cause at random failures of you 4 wd when you try to engage it.

[Jrp131191]

After 3 years I have found the root cause of my ADD malfunctioning.

The solution is very simple to prevent this.

The cause is moist getting inside the ADD.

Check to do: viewing from under the vehicle, you cannot see that the ADD has a small hose on top of it, this hose in my case (European Hilux Revo) sits at the right side of the engine under the bonnet, however is sits approximately 50-60 cm above the ground floor. Since there is NO breather on it, occasionally when drive through serious water, water comes in the hose.

How did i Fix it?
Simply punt in some fuel line hose into the hose (fits perfectly), and extend the hose way up high under the bonnet, and then bend it back downways to create a gooseneck. Now it is impossible for any water to ever get in there.

I suggest all Toyota owners with an ADD to check this hose, since it cause at random failures of you 4 wd when you try to engage it.

Hi, could you please look at the image I posted in the previous post and tell me if your breather hose connects into that?

[xychix]

After 3 years I have found the root cause of my ADD malfunctioning.

The solution is very simple to prevent this.

The cause is moist getting inside the ADD.

Check to do: viewing from under the vehicle, you cannot see that the ADD has a small hose on top of it, this hose in my case (European Hilux Revo) sits at the right side of the engine under the bonnet, however is sits approximately 50-60 cm above the ground floor. Since there is NO breather on it, occasionally when drive through serious water, water comes in the hose.

How did i Fix it?
Simply punt in some fuel line hose into the hose (fits perfectly), and extend the hose way up high under the bonnet, and then bend it back downways to create a gooseneck. Now it is impossible for any water to ever get in there.

@balsan, I'm pretty sure the hose came up at the LEFT side of the engine your arb breather is mounted to the left side in the engine bay (from the drivers perspective)

I suggest all Toyota owners with an ADD to check this hose, since it cause at random failures of you 4 wd when you try to engage it.

Hi, could you please look at the image I posted in the previous post and tell me if your breather hose connects into that?

Without a more distant picture to determine the exact location it will be hard to tell but it certainly looks like the A.D.D breather to me!

Note that Balsan has an Hilux Revo! The open hose was on the left front wheel side of the engine about half way to the front and was clamped in a holder that also guided the differential hose to a (after market) ARB breather.

Straight after fixing this I tried to find the 'open' hose on my Hilux Vigo (2015) but couldn't find that. Do know that the breathers (only 3 as far as I know) are mounted behind the engine to the firewall. Not sure where to find the add breather.

@balsan. I'm pretty sure the open hose was on the left side of the engine (from drivers perspective) and that your ARB breather is mounted to the left wing/firewall in the engine bay.

[Balsan]

After 3 years I have found the root cause of my ADD malfunctioning.

The solution is very simple to prevent this.

The cause is moist getting inside the ADD.

Check to do: viewing from under the vehicle, you cannot see that the ADD has a small hose on top of it, this hose in my case (European Hilux Revo) sits at the right side of the engine under the bonnet, however is sits approximately 50-60 cm above the ground floor. Since there is NO breather on it, occasionally when drive through serious water, water comes in the hose.

How did i Fix it?
Simply punt in some fuel line hose into the hose (fits perfectly), and extend the hose way up high under the bonnet, and then bend it back downways to create a gooseneck. Now it is impossible for any water to ever get in there.

I suggest all Toyota owners with an ADD to check this hose, since it cause at random failures of you 4 wd when you try to engage it.

Hi, could you please look at the image I posted in the previous post and tell me if your breather hose connects into that?

The problem was, that there was NO breather on the hose! I inserted a piece of fuel line hose inside the open hose, guided is way up (above the engine height, and then back down (Gooseneck idea), so now no water can get in anymore.

[Jrp131191]

Does anyone happen to have pics of the position of the large cog when the arm is completely engaged or disengaged? My gears were seized and the arm was stuck in an in-between setting. When I applied pressure I ended up pulling it apart. I marked where my teeth met the smaller cog but have no idea what position the arm was in..

[Jrp131191]

Ok guys I'm hoping someone can give me a hand with hopefully the tiny remainder bit of fixing my ADD. I'm far from qualified to be doing this sort of stuff on my own (as you would have figured by my lack of 'record keeping') but I want to learn and I've had fun doing it...

So as per above post I was unsure of how my large cog should be oriented. I did mark the teeth where it meets the smaller black cog but then realised I wasn't 100% about the position of the grabbing arm (it was stuck in a half way position and I only had pics from the front). I've got the ADD back on and shifting between 2h/4h and rolling the car a bit moves the arm/shaft to the other side. I jacked up the passenger side and made sure when in 4wd the tyre doesn't spin by hand and when in 2wd the tyre spins freely. It was opposite at first (wheel spun by hand when in 4wd) so I just turned the cog by hand to put it into the 'shaft locked' position. So it seems mechanically everything is working fine? I think

Only issue I have now is 4wd light not turning on... prop shaft doesn't spin by hand when 4h is engaged and as described above, the half shaft is locked in as well. What am I missing?

Where does the micro switch come into play? I tested continuity with my limited electrical knowledge and noticed that it doesn't form part of the motor circuit. Only seems to be a part of the 'circular contact' circuit that's on the large cog. Does this circuit have something to do with the 4x4 light? is my alignment of the cog still off and it is not orientating as it needs to be to turn on the 4x4 light?

Thanks a ton for any help.

[Jrp131191]

Alrighty I finally got it all working as it should. Here are some tips for anyone with little to no automotive knowledge like myself. The pic of the housing side with the large cog removed on justos first post is the ADD in 2WD (pic below).



Here's a pic (below) of the gear assembly in 4WD mode. That metal blade thing that sticks out is centered roughly on the bottom right screw hole. There are only certain positions the gear assembly will want to fit in so it shouldn't be hard to match the orientation from the pic. It won't be a "tooth by tooth" trial and error kind of task.



If you lay the plastic half of the ADD on a bench and look at where the plug goes into, the two left most contacts are to power the motor. Hook up some 12V through these two pins to make sure current is reaching the motor. Don't be an idiot like me and power the motor via its own contacts to test if it works.. . Check that the micro switch is working by checking for continuity across the two contacts on each side when the switch is pressed down.

Hope this helps anyone who needs it in the future.

[xychix]

note that the gearbox and transfercase breathers are on the firewall just above bellhousing.
The breathers for front diff and ADD are mounted just below the fuel filter.

(on my 2015 DC hilux Vigo)

Just added extra tube to all hoses and added a brass filter.

[HollandsN80]

Hi there,

Is any one able to confirm the RPM of the RE385 motor?
As the website fromt link supplied to show the motor specs has been down for weeks now, am looking at outsourcing the motor from somewhere else but cannot confirm the RPM of the 12V motor

Cheers!