Hey,

The factory rear diff lock on my 1996 4Runner isn't engaging. Dont think it has been used in a long time and I also suspect the previous owner dunked the diff in water frequently (launching his boat).

I tried the slow "S" turns on gravel for about 20 mins but the light just blinks inceasently. I'm not hearing anything comming from the back but I'm unsure how loud the sound should be (for the actuator) and whether I should be able to hear it over the engine.

Is there any way to test to see whether power is making it to the locker and to test whether the actuator is siezed? If the actuator is siezed can it be worked on or must it just be replaced (and how much is a replacement?)

Any tips on servicing it to make it slide in easier and any tips on how to drive to get it to engage?

Thanks in advance.

 

Are you in 4WD low when your doing this?

 

Yep, I am

 

Well I now think that it might be engaging but the light is just not showing it. With the engine off I can here a Rrrrrrrrrrrt sound that lasts about 3/4 a second when I press the button... would that be the actuator? If it is engaging what might be the likely culprit for the light not going on steady?

thanks

 

That is the motor moving, but there may be something blocking the fork. It might just need a good cleaning.



More than likely if the light is not on, it is not working. The way to see of it is, put it in 4WD low on the street in front of your house and engage the locker. If the rear tires chirp, it's on, if not, it's not.

 

Thanks...

I guess I will jack it up sometime in the next week to test it. I like your idea but I can just see myself breaking something

are they fairly easy to clean?

 

I hear they can get corroded inside.....there is a cover you can remove near the motor I think....take a peek inside. Get your WD40 ready.

 

Sounds like a plan... I'll be taking it apart sometime this week

 

Alrighty, so tested everything today, the locker works excellent, so its actually the light thats not working properly.

The light just flashes after I push the button, even after the locker has engaged, so any ideas what might be causing this?

 

could just be a bad switch, if the locker is working properly imo. contact toyota for a part number, then buy it off of 1sttoyotaparts.com but i dont even have an e-locker (˟˟˟˟˟) so wait for someone else to second my advice before you do it.

 

i dont have a locker either, so im not sure what it looks like, but in this wiring diagram (http://www.geocities.com/transalper/...ker_wiring.jpg) the part that is labeled Diff Lock Detection Switch is what sends the signal to the dash light once the locker is engaged. this may be faulty or have a poor connection. again, you should probably wait until someone with a locker can give you more specific help.

 

Thanks, I guess I will short out the wires leading to that switch and see if the light comes one then, if so that should mean faulty switch. if it doesnt come on that means wiring problem

 

Jack it up put it on stands and pull the drive shaft at the diffy end. Remove the cover/tape from the wiring harness near the diff. Take your multi meter, set to DC volts and tap into the GREEN and GREEN/RED wires. Turn the ing. on and in 4lo have some one push the RR switch as you slowly turn a wheel. As you hear the motor turning you should see around 10v on the meter. When the motor stops voltage should drop to 0 and you should feel the locker engage. If the voltage does not drop this means the motor has not made full travel and tripped the limit switch. Common problem and indicates the the actuator drive train is gummed up and the shift fork has not fully engaged and not tripping the locked indicator switch.

Next step, if the voltage drops and the light is still flashing, pull the locked indicator switch on top of the actuator, it looks like an oil pressure sending unit. On the business end of it you'll see a ball. this is the detent ball that holds the shift fork in the locked position and also trips the locked indicator switch. push up on the ball and the light should stop flashing. (don't forget to plug it back in to the harness to test it.) If the light is still flashing unplug the switch from the harness and jumper the 2 pins if the light indicates a locked condition that rules in a bad switch.

If the voltage drops, when the motor stops, and the switch is good and you still don't see a locked light, you still haven't ruled out the shift fork moving enough to trip the locked indicator switch. Now is the time to pull the actuator take it apart and clean it up relube and check to see if the shift fork moves freely then re-install.

 

Thanks for the great information, I shall tackle that. I'm almost certain the locker is working properly, I jacked it up the other day and spun the tires by hand with my friend and with the locker engaged the rear tires both turned in the same direction and with the locker off they turned opposite directions. I shall check all the connections next.

 

Good deal, tells you the motor is moving the fork, *BUT* how far? If not far enough for the detent ball to hold the fork in the locked position (and trip the switch if its working ok) than you're not really "locked" there could be just enough spline engagement to spin both wheels but not enough to be fully locked.

 

Alright great thanks. Hopefully it is just the sensor!

So when I check the sensor (take it out) I should have it in the unlocked position then eh? Since it holds the fork in the locked position?

 

Locked position, that way the light will change from transition to locked status.
BTW, I my have golssed it over, but I have never seen a sensor switch go bad. Gunked up actuators, bad connections and bad wiring jobs on retro fitted lockers, but never factory ECU or switches.

 

Yeah thats why I was surprised that the locker was engaging. This is an interesting problem. I'm hoping it a sensor though, because that would be the easiest way to rectify my problem

 

This is a great way to tear it up too. If its only engaging slightly, but not enough to trip the switch as Jake is suggesting, then if you were to get in a bind off road while useing the locker, it may sheer the splines off, destroy the fork, ect ect ect rendering the locker completely useless and possibly damageing other parts of the diff internals. Dont use the locker until your sure it is engaging correctly.

 

alrighty thanks for the advice... I haven't used the locker except for when I was trying to get it working, so hopefully I haven't torn anything up too much.