Front locker only? (1 Viewer)

[FZJ253]

Howdy. New 94 FZJ80 owner here.

I hit the trail for the first time over the weekend to test out the rig, and have a quick question about the factory lockers. My 80 is triple locked from the factory. The center diff locks works, but when I enagage both front and rear, only the front locker dash light stops blinking. This would seem to indicate that the front locker is engaged and the rear is not, but from the research I’ve done here so far, that seems..wrong? Shouldn’t the rear be locked as well, if the front is in? Or if there’s an issue with the rear, will the front lock regardless?

Any insight appreciated! Cheers.

 

[satchel]

My understanding is that if the rear is still blinking, it is trying to engage but cannot. Maybe try the rear only and do some slow speed turns on a dirt road and see if it will lock. If the rear isn't even blinking, that would be something else.

 

[Heckraiser]

If everything is working properly, the only options are
-rear locked
-front and rear locked
If your front is locked and the rear is not, you've got a malfunction to figure out. Sometimes just doing figure 8's in a dirt parking lot (with the switch set to RR locked) will get it to start working. If not, you most likely need to rebuild your rear locker actuator, but it could be a wiring issue or a bulb out in the dash?

 

[FZJ253]

If everything is working properly, the only options are
-rear locked
-front and rear locked
If your front is locked and the rear is not, you've got a malfunction to figure out. Sometimes just doing figure 8's in a dirt parking lot (with the switch set to RR locked) will get it to start working.

If not, you most likely need to rebuild your rear locker actuator, but it could be a wiring issue or a bulb out in the dash?

Thanks - yeah I suspect I’ve got some troubleshooting to do on the rear. I don’t think it’s the bulb since it blinks, it just doesn’t light up steady.

 

[z531519]

A working rear locker does not engage immediately, a proper slippage is needed for things to line up for it to engage. You will have to do figure 8s, or induce a single tire spin (put it up on stands) to confirm you can engage the rear locker. With that said, my rear locker (as many here) are frozen shut from corrosion which essentially prevents it from engaging. I had to replace mine wheres a bunch here had success rebuilding theirs.

also, the front will engage even if the rear is unable to engage as you noticed,

 

[Grench]

My rear locker engages, but whatever 'senses it' doesn't seem to be. So, the dash light keeps blinking. Quickest way to figure out if this is the case - in a parking lot with room - lock the rear locker in low range (CDL locked or not shouldn't matter much) - try to turn a corner on the pavement. If it's locked, the truck will be hard to steer and leaving black marks on the pavement. Might take a few figure 8s to get the teeth to line up for the locker to engage.

But - in most cases, it is still flashing because the rear locker is corroded, which sucks because you need it engaged before rear axle disassembly. So, the electronic locker needs to be addressed even if you don't plan to use it.

 

[z531519]

But - in most cases, it is still flashing because the rear locker is corroded, which sucks because you need it engaged before rear axle disassembly. So, the electronic locker needs to be addressed even if you don't plan to use it.

I installed mine with the Aisin brand from cruiseroutfitters. It is in engaged position. Once the old actuator is out, you can manually pry the pin in the locker to engage as you spin one tire. My old actuator was essentially fused together, probably never got used in its previous life as a van.

 

[SipLife]

Have you checked your position sensor? Sometimes the dash light will keep blinking even though your rear locker is engaged. Have you checked if the rear locker engages when the light on the dash is still blinking?

 

[ppc]

As others have indicated, check the sensor switch first, it is the most common failure. The sensor switches can be rejuvenated or replaced with a non-OEM at half the cost of OEM. All five sensors are the same, one for front, one for rear and three on the transfer case. Here is a link to a writeup by @george_tlc on the subject.

CDL Sensor/Switch

 

[FZJ253]

Thanks all for the advice. Very helpful. I’ll use this all to figure it out.

 

[Tools R Us]

Does the rear lock? When switched, can you hear the actuator run, each time it's switched it should run for a few seconds?

If yes. The rear only has 5 teeth, so can be difficult to lock when not needed, best test is to jack up the rear, switch it on and turn a tire. When open the tires will turn in opposing direction, when locked, they will be locked together. Should only take about 1/5 of a turn, max, to lock.

If no response from the actuator, when switched, do you hear the relay click in the passenger kick panel? All of this needs to be done with the center locked and the CDL light on.

The switch that turns the blinky light solid is only a confirmation that the locker is engaged. Nice to have, but has nothing to do with the operation of the system.