Triple Locked help (2 Viewers)

[nhall80]

i noticed awhile back that my rear locker wasn't engaging. The front indicator would stop blinking, but the rear would steadily blink. This was a few months ago. Yesterday, I decided to investigate the issue and found that now my front locker isn't engaging. Both blink forever. I can also confirm by sight that they are in fact not engaged.

Also, I'm doubtful that my center diff lock is engaging when I put into 4L. I can't remember if there is a dash indicator for the center diff lock (?).

I have a FSM and understand the basics of how to diagnose (that center diff lock relay does not look fun to access for testing).

Here is my question: for those of you who have experience with this - what is the most likely culprit? Does the fact that the rear and front lockers went out in sequence a couple months apart tell you anything?

 

[Pascoscout]

There is an indicator on the dash for the CDL. Its orange. You should also see the ABS light come on once the CDL engages. If I recall you cannot engage the front or rear without the CDL engaged.

It is odd that your front would work but not the rear. The switch turns the rear on first, then the front. I don't know if there is a failsafe to prevent the front from locking if the rear does not but the way the switch is designed, you cannot turn on the front without turning on the rear.

Have you opened up either actuator to see the condition? A lot of times the o-ring seal fails and the insides around the gears and magnets get corroded causing non-function.

One good test is to take a AA battery (1.4volt) and apply it to the leads on the locker. It's shown how to do this for the front in the FSM, rear is similar. The AA battery should move the actuator. If it doesn't you may have a bad connection or failed motor.

 

[booradley]

I would start by replacing the switches in each actuator. They are cheap and replacing them started me on the path to success. Blinking lights are strong evidence of faulty switch.

 

[Fj80oregon]

Try searching all the information you need is readily available in various threads, start with your CDL.

 

[bj70bc]

theres a centre diff lock sensor that need to tell the rear to engage, that thing can sieze up and need attention, also the rear actuator can crap out and need cleaning / replacing

 

[manofthewoods]

i noticed awhile back that my rear locker wasn't engaging. The front indicator would stop blinking, but the rear would steadily blink. This was a few months ago. Yesterday, I decided to investigate the issue and found that now my front locker isn't engaging. Both blink forever. I can also confirm by sight that they are in fact not engaged.

Also, I'm doubtful that my center diff lock is engaging when I put into 4L. I can't remember if there is a dash indicator for the center diff lock (?).

I have a FSM and understand the basics of how to diagnose (that center diff lock relay does not look fun to access for testing).

Here is my question: for those of you who have experience with this - what is the most likely culprit? Does the fact that the rear and front lockers went out in sequence a couple months apart tell you anything?

To add to posts 3-5...
The sensor that indicates locker engagement is actually called a switch.
I was having trouble a few weeks ago with my rear locker; got a new one from autozone..
Problem was still there. Took the old one and sprayed the connector with contact cleaner and manually cycled the switch (vigorously to its full throw), put it back in. Works better than ever before.
Not difficult, and cheap.
Best of luck

 

[nhall80]

Thanks for the input guys. I was able to look at it again this morning. I found that the L4 Position Switch was unplugged. This has remedied the CDL indicator dash light (and CDL is engaging). Also, the front locker engages. However, the rear is still not engaging. Pascoscout, you pointed out that the front should not engage if the rear does not engage. That makes sense to me, but doesn't seem to be the case here....strange. Regardless, I'm going to clean and manipulate the rear switch and see if that fixes the rear.

 

[nhall80]

I wonder if it is true that the rear must engage in order for the front to engage, that maybe my rear IS engaging, but the dash indicator is still flashing due to a faulty switch...is this possible?

 

[manofthewoods]

Thanks for the input guys. I was able to look at it again this morning. I found that the L4 Position Switch was unplugged. This has remedied the CDL indicator dash light (and CDL is engaging). Also, the front locker engages. However, the rear is still not engaging. Pascoscout, you pointed out that the front should not engage if the rear does not engage. That makes sense to me, but doesn't seem to be the case here....strange. Regardless, I'm going to clean and manipulate the rear switch and see if that fixes the rear.

I have found that my front typically engages quicker than the rear almost every time (assuming I turn the dial all the way from the get go). So, that leads me to believe that engagement is independent. 99% sure of this.

 

[manofthewoods]

I wonder if it is true that the rear must engage in order for the front to engage, that maybe my rear IS engaging, but the dash indicator is still flashing due to a faulty switch...is this possible?

to your second point above...
yes. see my post #6 above. When I had flashing for the rear locker, it was actually engaged, but, the "switch" (aka sensor) wasn't sending the signal to turn the light "on."

 

[nhall80]

I'm also thinking they must be independent. I cleaned the switch really well and it ohmed correctly. Put it back in...still no engagement. I drove around in figure 8's in a gravel lot for several minutes...no luck. Going to remove and inspect the actuator next. But that's for tomorrow I think.

Found this thread helpful for actuator info: Rear Diff Lock Actuator removal - https://forum.ih8mud.com/threads/rear-diff-lock-actuator-removal.228094/

 

[Pascoscout]

Pascoscout, you pointed out that the front should not engage if the rear does not engage. That makes sense to me, but doesn't seem to be the case here....strange. Regardless, I'm going to clean and manipulate the rear switch and see if that fixes the rear.

Yeah, I wasn't really sure. I guess I have always waited for my rear to engage before trying to engage the front. I normally try not to use lockers unless I need them and then I try to get out of whatever I am in with the rear only. Will only use the front if all else fails.

 

[jonheld]

There is no logic regarding the rear locking before the front. The factory switch has the rear first, but that's all there is. The front will almost always lock before the rear due to the number of splines in the locking collar. The front is fine spline, while the rear is coarse spline.
As stated earlier, the center diff has to lock before the axle lockers will work on a stock 80.