FRONT LOCKER WON'T ENGAGE- how to fix

[acey]

My front factory Diff locker won't engage, Center and Rear work fine.
It had the wiring harness missing for the front differential locker. I since installed a OEM wiring harness but that did not solve my locking problem.

Anyone know how to fix this issue?

 

[Riley]

This is a needle in a hay stack but tell us more:

- what do the indicator lights do in the dash? blinking for the front?
- do you measure the voltage at the connector to the locker? - I'm not sure how it's wired but others will. It's likely a constant voltage there when the switch is engaged.

Have you ever played with an 80 in locking the front diff? it's not always easy on an older truck that hasn't been locked for awhile. You need to turn sharp to the right... and back and forth to get the gears to line up.

 

[acey]

I get a "blinking front locker" light and it does not feel as the front locks. The lockers are factory (K-294 model truck).

On the other end, the center and rear lock without a problem. New fluid serviced by toyota. 2 months since I bought this truck. This remains my only issue with this beast. Have not done the voltage check yet.

 

[acey]

FIXED ANOTHER ONE


Ok, since nobody had an answer I went ahead and got my tool kit and some general mechanical knowledge.

Here is what I did:

Pulled the locker motor of the front differential. In order to do that you have to remove the front right tire. Use a 12 mm to undo the factory locker motor.

Removed the motor and checked that the motor moved when powered with the front diff lock turned ON. The motor worked.

Next thing was I put my finger in the little hole where the motor goes in. Wiggled the little gear inside that you feel and move the Axel back forward with the brake disk SO IT LOOSENS THE GEAR MECHANISM. Then I reassembled everything and TA-DA it WORKED!!!

NOTE: Check you brake caliper mounting bolts when you do this procedure (while you have the wheel off) as mine were loose!

 

[CreeperSleeper]

Well done!

 

[Tenzig Norgay]

Way to go, this sounded like a pretty easy procedure, and I'm sure it will come in handy for some with the stuck front diff problem. Wish i had lockers

 

[acey]

More detailed outline of the procedure:

Just take the 2 nuts and 1 screw that hold the locker motor in place off, nothing will fall off or go sproing just pull it out of the differential housing. Test the motor by noting the position of the motor gear, set parking brake, turn the car on, shift lever to 'N' (large lever), then put the 4X4 lever (small) in 'L' so the center diff locks, now turn the front and rear diff lock on and go see if the motor turned (gear should have moved).

 

[RedTacoma]

Just to let you know. You can move locker with 1.5 V battery when you testing no need to use dial.
If you use battery you can set notch on the locker to correct position. Full procedure is in the FSM. (posted on forum somewhere)
Based on that.
I did small test setup that I can use to engage-disengage locker with out ECU. (One day I will do the writeup) I wanted to be able to bypass computer to test lockers inside differential and outside of it.
For power, I used radioshack's AA battery holder,

For testing the locker in diff you need to add 5-way relay (cant find on their website) that will take input from lock/unlock sensor. this way you know when system is fully locked and when not.

 

[acey]

Nice idea too about the batt, but how would you know that your engage solenoid works? You exclude THREE possible scenarios by using the differential lock switch to turn the motor. You check agains if the following faults:

1. Your solenoid is faulty
2. Your Switch is faulty
3. Your Wiring is faulty

 

[RedTacoma]

Nice idea too about the batt, but how would you know that your engage solenoid works? You exclude THREE possible scenarios by using the differential lock switch to turn the motor. You check agains if the following faults:

1. Your solenoid is faulty
2. Your Switch is faulty
3. Your Wiring is faulty

Above 3 are easily tested with $10 multimeter

with out driving the truck.

I did the setup to remove guess work of driving in circles to figure out whats not working.

total cost of setup with multimeter is around $20+ dollars and it removes guess work. That is exact setup that is suggested in FSM for testing the locker. My Only change is, FSM tells you to use truck battery to supply power which I did not want to use since I am not very happy with runnign so much voltage while testing things.I am using 1.5V battery instead.


EDIT: I wish I could get Toyota plug. That would make easier to run diag. and would be nice tool to test lockers when buying a truck with out being affraid to brake something