Green 4x4 Light Flashing, manual T-Case

Shifted into and then out of 4HI today and the green blinking 4x4 light will not shut off. Front driveshaft is disengaged.

Anyone have this issue previously?

Had the front of the truck off the ground this morning changing front rotors.

Thank you,
Matt

 

the 4WD light will flash after going into 2H and stop flashing after a few feet of driving.

 

Flashing means the system is waiting for the ADD to actuate. I’d try going into 4wd again while moving and back out also while moving.

 

Yep tried it. My 4WD system gets used regularly as well. No matter what still flashing green.

Pulled the skid, checked the ADD connections and pins and all look clean. Small breather is connected as well.

 

ADD is beeping on front diff with key in accessory. Confirmed by unplugging it.

 

Sounds like an add problem

 

Does anyone know the torque specs for the ADD casing to front diff? 4 Bolts.

I am going to guess there is corrosion in the electrical motor from years of off road and water. Replacement seems fairly simple.

I am still under a powertrain warranty with this truck but it just might be easier for me to do it then a dealer trip.

Thank you.

 

Check here: https://www.to4runner.net/automatic_disconnecting_differential_actuator-834.html

It looks like 15 ft-lbs if I understand the question.

 

That's it. Thank you so much.

 

It's made for on the fly but it has to mesh. Don't they have one of those solenoids that disengaged the front axles on Dodge...and it would stick and I was stuck. I do everything in neutral especially low. Neutral will put slack in the driveline for mesh. It's unnatural to turn a button on the fly. I have to read owner manual sometimes to know what it's doing and what I need to do.

 

I have manual T-Case lever but the ADD on the front diff is automatic. I do not know how many thousands of times I have shifted to 4HI in the 4Runner when moving but I normally release pressure off the throttle.

 

You may be able to just tap on it like my Dodge. I carried a long screwdriver or small mallet. I bet if you start over and drive a little farther and engage in neutral. It will work. What mileage do you get with those

 

I tried tapping it with a rubber mallet, no luck. I am fairly familiar with how to get the truck into 4WD. No amount of selecting neutral, backing up, turning the wheel slightly while moving engage 4WD. The ADD itself is making an electronic beeping type noise as well, which the truck has never done before in 51,000 miles. I was in Nova Scotia last month and it might have been submerged and taken its final deathblow. I pulled a bunch of mud off the unit itself but there is a small breather that could allow moisture in to kill the motor.

 

I have to go back and read my manual. I know nothing about a Tacoma system or if they have one. I like my AWD and limited slip. Probably not much slip like a Supra limited slip. I just have to decide wh where to point it. Great authorized only interstate direction changing tool. You don't need a road even.

 

On a side note, has anyone changed the ADD out of the front diff?

Do I need to drop the diff or can it be manuevered out? Looks like the 4th passenger side upper bolt is tricky to get to but not impossible.

 

Did you check it for water contamination which is rare. Take it apart and polish the shaft with jeweler rouge for steel and a Dremel tool and polish it to make it slicker. TW25B nano gun grease is a nano molecular structure and fills the metals pores. I use on my gun or what. It really traps the dirt in the grease. If you dug mud off, check plug and wires. If you have help get a test probe and check it in and out while someone is shifting for. Chock blocks to buddy. That will give you a starting point and let you know if wires are good. Take battery cable off for 2 months to go back to default. It might forget it happened and give you another chance.

 

If it has bolts. It's probably a fork on a shaft with electric solenoid. It might reset the solenoid. Toyota are usually simple and with all this integrated tech. Check rear hatch. Mine wasn't shut the other day and but open door light wasn't on. Trac lights, and I guess it is a safety thing. If hatch reads open it probably assumes some is back . All I could think of. It's to ger your attention because one thing is wrong somewhere.

 

Just tight enough and no more probably

 

My Trac, hazards and another light came on when hatch started moving and vibrating. You might Google to see if it is a common problem

10-15 lbs

 

Flash your ECU Take negative cable off and walk away for at least a couple minutes. Don't worry or think about it and start again. As long as you did forget to plug anything in. Cheapest way to know if you have a real problem.

 

Friend at dispensary
He trade for 17 Tacoma 6 speed. I don't know nothing about them except I drive and apple and them an orange. Torch and a little hear. It probably has RTV on it. It should lift up.

 

Did you ever fix this? I am having precisely the same issue, just started today. I can switch the manual transfer case shifter to 2h, 4h and 4l but nothing gets rid of that blinking 4wd indicator. I can hear it beeping very softly when the ignition is off and ACC is on.

This is the only thing I haven't tried but will tomorrow.

It seems like it's working fine but the 4wd light will not stop blinking.

 

Mine was a corroded internal ADD. New front actuator solved the problem. The extremely tight breather had a tear in it and I believe it let moisture in over time.

On another note, I just got done a few months ago replacing the rear diff lock actuator, the actual aluminum housing on mine cracked and failed.....

 

How difficult was it to remove the ADD unit and replace the breather hose?

On the rear locker actuator, do you think the crack was damage related, or corrosion related? Any pics of the housing?

 

Dealer did the front ADD for me, as I was still under 60,000 miles I thought it was drivetrain related....oh no, its electrical and I had to pay. I called corporate, said the breather was damaged that let moisture in but still no luck. Anyway....

The rear diff actuator was a mess when I removed it. Couldn't get the rear end to lock which was strange as I use it a good amount. Pulled the actuator and it was corroded between the housing and the rear diff casing causing a crack around the circumference of the gear housing. I am going to guess freeze and thaw contributed to it as well.

Now...this was under 60k miles too and probably would have been covered by the warranty but oh well.

Followed the service manual procedure for replacement, you have re align the toothed engagement for the actuator in the diff and I had to jumper the pins on the new actuator to get the alignment mark on the cog set up. Other then that, its in an area that you would not think about spraying wool wax but when I had it apart I wire brushed and coated it real well. Literally the one area on the truck I had not sprayed wool wax.

I also accidentally pulled out one of the threaded rods that goes through the diff where the rear diff actuator bolts up to, so I had to put that back in with a little loctite. All in all took about 2 hours.

Ordered the rear actuator from Rock Auto. Aisin part, identical to the Toyota part, $600 less.

 

Thanks for the details on the rear e-locker actuator. The gap between the diff and the actuator housing is horrible…it’s a perfect trap for mud and other crap, but the gap is small enough that you don’t even notice there is a gap there at all. Last summer I realized mine was caked in mud. Only after a thourough cleaning and positioning myself just right did I even realize there is supposed to be a gap.


I think this is going to be an eventual replacement that I’ll have to do just because of living in the salt belt, so it’s nice to hear others experiences.

 

I missed this part, I just tried it. To my complete amazement, that worked. Actually now it switches faster than before, almost immediately instead of having to roll 20-30 ft. I expect this will be a problem down the line but for now I guess I need to shift into 4x more often.

A friend suggested checking the wiring before taking it in for a warranty claim. Connector looks good and everything was seated securely. Followed the line up to the engine bay, no issues. 4wd fuse was ok (I'm assuming that runs the A.D.D. since it isn't marked specifically anywhere).

While I was under there I hit it about 5x where it meets the diff and once gently on the unit itself, both areas circled in the pic. After I drove it and it worked immediately when I tried shifting to 4h. Shifts back to 2h just as fast. Tried it a few more times, no problem.

 

Good to hear that worked. With as much as I use 4WD and lock the rear diff I was fairly confident that both my failures were not from a lack of use. I still dont like the tight breather on the ADD on the front diff and would like to extended that line a small amount.

 

Update on this, the issue did come back and I ended up getting the A.D.D. unit replaced under warranty (with 2k miles left...lucky). I read through the paperwork and they essentially diagnosed it by unplugging the unit and seeing that the blinking 4x4 light went away. They then tested the unit itself and it failed continuity, so it sounds like an electrical problem within the unit that prevented it from working versus it just being stuck. Makes sense in that it's only a year old in a desert climate.

They started with saying they need to check the entire electrical system and part of the dash needs to come out for that. I said do not do that, test the A.D.D. unit first. After some back and forth I think they transferred the job to another mechanic who figured it out right away.

They went through the Toyota corporate list of questions, so just a heads up one was - "Did you ever offroad your vehicle?" which is corporate speak for "Did you use the vehicle as designed and intended because if so we're not covering this and we'll try to blame you." They will check underneath to verify. Also "was the light blinking before you installed aftermarket shocks?" and "were the shocks installed by a professional?" Common sense answers resulted in replacement completely covered under warranty - $0 out of pocket.