Rear e-locker does not engage

[rhyary]

Last night I installed a new rear e-locker.
I tell you, I understand why the dealers only want to install new parts instead of repairing.
And , everything works as new.
So sometime this winter I will be trying to fix the old e-locker using raventai instructions.
Since I will have time, I will try to source parts for it, if needed.
I also installed Slee Rear e-locker guard.

 

[Tools R Us]

Did you buy a new one, ouch $$$? I had to replace the CDL actuator.

The inside the actuator electrical problems that I have seen are: The most common is the slide position contacts not making good contact, probably not your problem, the relay wouldn't click. On the motor side, stuck, worn, broken brushes, not making good contact, causes the motor to have low power or not run. On my CDL smoked the armature windings, probably not your problem, I could smell the smoke that had escaped as soon as the cover was removed.

 

['74 UA FJ]

My rear locker is not working. CDL and Front locker are fine. The relay for the rear is not clicking.

What would you look at first, second, third, etc.?

 

['74 UA FJ]

Fyi, when I pulled the actuator cover off, water drained out......I've sprayed wd40 in there to try to displace the rest of it.

 

['74 UA FJ]

AFter even further analysis, the aluminum actuator cover is cracked. I don't know when that happened, but that's probably how the water was introduced. Is that cover sold by itself? It's getting some rtv for now.

 

['74 UA FJ]

Bump. I guess I'm going to have to remove the whole assembly from the housing...ugh. There goes next saturday.

 

[rhyary]

There is a thread about how to fix the rear e-locker.
However, I bought a new one, and saved the old one to try to fix it sometime in the future.
To me the fix was a bit overwhelming and I took the easy and expensive way out

 

['74 UA FJ]

I know. I did not want to start the 1,728,345th thread on lockers not engaging. I'm hoping TRU will chime in here.


What are the most likely spots for a bad electrical connection?

 

['74 UA FJ]

bump.

 

[Tools R Us]

My rear locker is not working. CDL and Front locker are fine. The relay for the rear is not clicking.

What would you look at first, second, third, etc.?

From post #7

If the relay doesn't click; it could be a bad connection (rare), bad ECU (very rare) or most commonly a bad connection at the position limit switch in the actuator. The relays in the ECU are powered from the rotary diff lock switch, ground comes from the position limit switch in the actuator.

Most often the limit switch contacts are corroded/not making good contact. Look at the pic below, I colored them red.

Fyi, when I pulled the actuator cover off, water drained out......I've sprayed wd40 in there to try to displace the rest of it.

Water will make the limit switch contacts corrode. From post#7:

In my experience, most actuator problems are from moisture and require it to be taken apart, cleaned and greased. IMHO the breather isn't in the best place, terminates in the driver side wheel well, I use vacuum line to extend into the jack compartment, ending the problem.

AFter even further analysis, the aluminum actuator cover is cracked. I don't know when that happened, but that's probably how the water was introduced. Is that cover sold by itself? It's getting some rtv for now.

There are no new actuator parts available. The cover's only purpose is to provide a bushing for the gear shaft to ride on and seal the housing. As long as the cover still holds the gear/shaft in the proper place and can be sealed, I would run it. Picture of the crack? The actuator must be sealed water tight, on all of them I have done, the o-rings were dead and the o-ring grooves corroded, so I just seal them up with silicone.

Read the FSM clips in the second pic on post #7, does a good job of explaining the operation of the circuit. The 2nd pic below is of the CDL circuit, but operation is the same, note that the limit switch supplies ground for the relays.

This post ( IH8MUD.com - View Single Post - Rear Locking Dif Assembly Help ) explains properly timing the actuator.

 

[subzali]

Going to bump this thread and tag on. Hopefully @Tools R Us or some other guru may have some input. My rear e-locker stopped working. Tonight I got both rear wheels up on jack stands and checked things out.

-Limit switch passed the FSM test for continuity.
-CDL is locked and showing constant illumination.
-I can hear the locker motor run when I switch to rear lock, and running back when I switch the lockers off.
-As I left the switch on rear lock, I spun one rear tire. Looked across and the other rear tire was spinning the opposite direction. But the locker never engaged.

Can someone help me understand what would keep the locker from engaging if the motor works as it's supposed to?

 

[Tools R Us]

Possibly the output portion of the actuator is bound, corroded, needs to be cleaned and lubed?

 

[landtank]

My experience is the planetary gear assembly is bound up. When you here yhe motor spin it is loading up a spring and it's that spring that moves the shaft. That assembly sits in bushings which can get corroded and gunned up which over wheels the spring.

Or you could have twisted you splines and jammed the locking collar on those twisted.

Hope for the bound up planetary assembly!

 

[Beej]

If the motor is working, you only need to open up the main compartment on the actuator. You can actually do this with the locker still on the truck without a bunch of pieces flying everywhere.

If/when you pull the assembly out, remember to mark how it was installed so once its lubed up, you can install as it was. The positioning affects how far the actuator rod travels into the diff

 

[izzyandsue]

You can remove the plate next to the locker to see if it actually moves. It may not move enough to lock the diff, or if it was removed someone might have put it back incorrectly.

If you do remove the plate (or locker), the gasket you need is FIPG oil resistant. This is the plate removed picture below

 

[subzali]

Possibly the output portion of the actuator is bound, corroded, needs to be cleaned and lubed?

I'm hoping this can be reached without taking the actuator apart.

My experience is the planetary gear assembly is bound up. When you here yhe motor spin it is loading up a spring and it's that spring that moves the shaft. That assembly sits in bushings which can get corroded and gunned up which over wheels the spring.

Or you could have twisted you splines and jammed the locking collar on those twisted.

Hope for the bound up planetary assembly!

This sounds like the actuator has to be taken apart. This is a dd not a wheeler so twisted splines would be highly unlikely.

If the motor is working, you only need to open up the main compartment on the actuator. You can actually do this with the locker still on the truck without a bunch of pieces flying everywhere.

If/when you pull the assembly out, remember to mark how it was installed so once its lubed up, you can install as it was. The positioning affects how far the actuator rod travels into the diff

This is the 3 screws on the actuator cover? I guess I thought small parts started coming out at the point of removing that. What am I looking for when I get in there?

You can remove the plate next to the locker to see if it actually moves. It may not move enough to lock the diff, or if it was removed someone might have put it back incorrectly.

If you do remove the plate (or locker), the gasket you need is FIPG oil resistant. This is the plate removed picture below

Got that far and the shaft is not moving. When I try to loosen that bolt it feels tight and I'm scared of snapping it off and then I'd really be screwed.

 

[subzali]

I got the cover off. A little rust dust on the bottom but overall not terrible. I could feel the spring tension as I was pulling it out, seems like I can get it back together ok though.

 

[subzali]

Helped the shaft along and cycled it a few times then out it all back together. Went for a short drive and had successful engagement every time. So going to call it good until I have another problem. Will do some more reading in case I have to get into the guts of the thing, which it sounds is the ultimate fix. Thanks to everybody that responded.

 

[LINUS]

Shove a smear of grease in the socket for the indicator & the actuator. These are getting old & tarnish / corrosion only needs some water or mud sloshed up there to make for intermittant issues we all love.

And since it sounds like yours was sticking maybe find a dirt lot every ~2 wks for awhile & do locker excercises / figure 8's.

A little of that & you may never have to post here again!

 

[Beej]

Also, if you search locker rebuild, you'll get looooots of pictures. There's a thread by landtank and another with a PDF attachment and they're both good.