Rear Diff Lock Question (1 Viewer)

Joined
Apr 21, 2014
Messages
23
Location
Dallas
So I have checked and replaced the actuator indicator switch. It works fine, but RR locker indicator just flashes. Jacks up the rear and checked to see if it was locked and it wasn't. Is there anyway to check the rear locker actuator function and get it to activate without pulling it off? Can an external power source or battery be used to get it to cycle? I have been searching threads but nothing yet.
 
Joined
Jan 16, 2013
Messages
443
Location
Atlanta, GA
I would just find a field or dirt road and just drive slow (under 5mph) and turn the wheel back and forth a bit. That will help line up the locker actuator gear. Ive heard of some lockers being very stubborn and taking a while to get on, but once you start using them, then they start to come on quicker. You can use a battery to test the actuator but I would say that you should pull the actuator in order to test it. It would be hard to power the locker with a battery and do everything else. I would just pull the actuator and turn the rear locker on with the dash switch, and see if it actuates. If it doesn't move in or out then I would saw either your actuator is messed up, or there's a wiring problem. That is when I would test out the actuator with a 9V battery. here is how to test that (post #654)...
https://forum.ih8mud.com/threads/my-first-toyota.581380/page-33
 
Joined
Apr 21, 2014
Messages
23
Location
Dallas
I would just find a field or dirt road and just drive slow (under 5mph) and turn the wheel back and forth a bit. That will help line up the locker actuator gear. Ive heard of some lockers being very stubborn and taking a while to get on, but once you start using them, then they start to come on quicker. You can use a battery to test the actuator but I would say that you should pull the actuator in order to test it. It would be hard to power the locker with a battery and do everything else. I would just pull the actuator and turn the rear locker on with the dash switch, and see if it actuates. If it doesn't move in or out then I would saw either your actuator is messed up, or there's a wiring problem. That is when I would test out the actuator with a 9V battery. here is how to test that (post #654)...
https://forum.ih8mud.com/threads/my-first-toyota.581380/page-33

Thanks I appreciate it. I did as you said driving around. No luck. I pulled the switch and then checked it with a paper clip. When I short the switch the light turns solid red, so it would appear the switch and CDL are okay. I have read some threads on pulling the actuator, but bit seems there are a lot of things that can go wrong if you don't know what you are doing...and I am not familiar with the actuators internals, so I was hoping to be able to try to find a way to try to manually engage it with an external power source to try to narrow down where tge problem was...
 
Joined
Aug 30, 2007
Messages
992
Location
NB, Canada
If you pull the indicator switch off you will see the actuator fork. (switch ball rides on fork actually). Go ahead and test the actuator on the truck with aligator clips and see if the fork moves. Just be certain that you have the wiring correct. If it moves both ways then it isn't the actuator and you can look for something else. If it doesn't move you will have to pull the actuator. None of this is particularly difficult but you need to follow instructions on getting it back together. Either raventai of beowolf has comments in a thread on how to measure the rod position etc to get it right. Most likely your actuator motor has gotten water in it and now won't work. I've found the seal on the stamped metal motor can is prone to water because the oring isn't very good. Some motors have loose magnets so be aware that they may move on you. They have N&S poles so you really have to be careful in a lot of ways. I epoxied mine back in one motor can and it works.
 
Joined
Aug 30, 2007
Messages
992
Location
NB, Canada
ive never tried it but you might be able to remove the motor can with it on the truck. You'd have to be crafty with paperclips or something to get the brushes back over the commutator on reassembly though if you took out the rotor. Find a wiring diagram and the thread i mentioned above and you should just have the work left to do. Lots of people can help if something comes up.
 
Last edited:
Joined
Jan 16, 2013
Messages
443
Location
Atlanta, GA
Thanks I appreciate it. I did as you said driving around. No luck. I pulled the switch and then checked it with a paper clip. When I short the switch the light turns solid red, so it would appear the switch and CDL are okay. I have read some threads on pulling the actuator, but bit seems there are a lot of things that can go wrong if you don't know what you are doing...and I am not familiar with the actuators internals, so I was hoping to be able to try to find a way to try to manually engage it with an external power source to try to narrow down where tge problem was...

Taking the actuator off isn't really the hard part. The harder part is getting it back together properly. I wold check the FSM for information on how to pull it properly. The only problem with testing the actuator on the truck with a battery is that you'd have to hold on the battery for a long period of time. when testing it you dont want to hold onto it for a long time because that can mess up the actuator. When bench testing it, as soon as you tap the correct prongs on the plug, the locker rod should move in or out.
 
Joined
Aug 30, 2007
Messages
992
Location
NB, Canada
I do not understand why you have to hold it a long time. I have done this on the truck before two times and it is no different than on the bench except on the truck you can hold power if you want and not worry about the adjustments being changed. There are brushes on the big gear that cut power to the motor once end of travel is reached and springs in the actuator that allow the motor to do its thing even if the dogs on the axles are not lined up.
If you have the indicator switch out you will see it move unless there is a problem in the actuator.
Rebuilding actuators is pretty easy but dedicate 4 hours for the complete job. People quote less time but in my experience it pays to be careful and certain that you have all adjustments correct before reassembly.
One thing you could do is measure the shaft after you remove it and record that as you unlocked shaft position. This way you should be able to clock the gears on reassembly.
 
Last edited:
Joined
Feb 22, 2012
Messages
2,894
Location
atlanta
Thanks I appreciate it. I did as you said driving around. No luck. I pulled the switch and then checked it with a paper clip. When I short the switch the light turns solid red, so it would appear the switch and CDL are okay. I have read some threads on pulling the actuator, but bit seems there are a lot of things that can go wrong if you don't know what you are doing...and I am not familiar with the actuators internals, so I was hoping to be able to try to find a way to try to manually engage it with an external power source to try to narrow down where tge problem was...

Do not open the actuator until you've tried everything else first. like you said, the internals are tricky and putting it back together incorrectly is gonna fxxx it up. But pulling the entire actuator off the diff is easy though, just need a few sockets (10mm, 14mm, maybe one other for the "shield") and like 15 minutes. Measure the length of the rod so that you can get it back to this length for reinstallation. Like @pandathrust said, to manually engage it with an external power source, use a 9V battery to TAP the two thick dark green wire prongs (holding the battery to the actuator for a long times will fry that thing so be careful). If it moves a little, great. To get it to move in the opposite direction (back in), reverse the power and ground on the 2 dark green prongs and tap.

Doing all this while the actuator still on the truck is gonna be a PITA. When i was testing mine, i would've needed 3 hands to hold the battery and keep the wires connected to the battery and contacting the actuator prongs. Plus you'd need to ensure that the locker teeth are lined up with the teeth on the carrier (which is very difficult) or else that actuator rod is going nowhere.

Hopefully that will solve the ornery actuator problem. If not we'll try and come up with some other solutions for ya to try.
 
Joined
Apr 21, 2014
Messages
23
Location
Dallas
If you pull the indicator switch off you will see the actuator fork. (switch ball rides on fork actually). Go ahead and test the actuator on the truck with aligator clips and see if the fork moves. Just be certain that you have the wiring correct. If it moves both ways then it isn't the actuator and you can look for something else. If it doesn't move you will have to pull the actuator. None of this is particularly difficult but you need to follow instructions on getting it back together. Either raventai of beowolf has comments in a thread on how to measure the rod position etc to get it right. Most likely your actuator motor has gotten water in it and now won't work. I've found the seal on the stamped metal motor can is prone to water because the oring isn't very good. Some motors have loose magnets so be aware that they may move on you. They have N&S poles so you really have to be careful in a lot of ways. I epoxied mine back in one motor can and it works.

Test it with alligator clips using an external battery?
 
Joined
Aug 30, 2007
Messages
992
Location
NB, Canada
that is what i did, also truck on stands so you can rotate wheel and see full engagement. Without rolling wheels to line up dogs I think the fork only moves a little bit which might be hard to see in the dark.
I can't recall the voltage to the actuator but seem to recall it being less than 12v. Like people said 9V seems to work.
 

Users who are viewing this thread

Top Bottom