Rear diff lock won't engage

You need to be moving and making a somewhat gradual turn. A very simple way of looking at it is like a manual gear box. If the teeth of the gears dont line up, you arent going to be able to shift into the desired gear. A locker is essentially teeth that lock both sides of the diff together. If they arent perfectly lined up when you hit the switch (and most likely they are not) then its not going to engage. The only way to make them line up is to spin one side (one tire) faster than the other. Hence making a slow turn while engaging. Driving straight forward or back isn't going to help as much because both tires are spining at the same rate. Do that and it will fall into place shortly.

 

For reference, the exact same principle applies to people having a hard time shifting into 4Lo. If you try it in Park or with your foot hard on the brake, you aren't allowing the gears to mesh up. But if you're in Neutral and let your foot off the brake until you barely start to move forward or backward, it should shift in right away

 

Makes perfect sense.

 

I found that turning the steering wheel a little left and right can move the axle just enough to click it in gear. I also find this works when having trouble getting in or out of 4-lo.

 

i see you have an MT, i had some issue getting mine out of 4lo one time, just kept flashing at me. Turns out i didnt have the clutch pedal pushed ALL the way to the floor, my husky mats were keeping my pedal from hitting the switch. Not sure if that matters for the locker or not, but worth a try

 

I', pretty new to the wheeling scene and have only used the locker once. I had a hell of a time getting it to engage, but eventually it did. I was on a hill climb and needed to bump over a good sized rock, but no momentum or traction to get any. Eventually it went in and I left it until I was done wheeling. It went out slightly easier.

Seems as if i would have had better luck engaging before needed (being I was on trails so no issue with pavement) giving me the ability to turn mesh the gears? I have a '12 with 100K, so I just assumed it was a little frozen from lack of use.

Will engaging it more frequently aid in this? I was thinking about preventative maintenance type just locking it once a month or so to keep things free? Or do I just need to learn how they work to engage it properly? Thanks as there have already been some useful answers in here.

 

You can engage the locker right after you engage 4lo and leave it locked the whole wheeling trip. I did this with my 2nd gen with no issues, leaving it locked for 2-3 days at a time, including when sleeping at the camp spots. The rear locker isn't as intrusive to steering as a front locker (like those on Jeep Rubicons or Colorado ZR2s).

 

On the third gens after restarting the engine the truck will disengage the rear locker. If you press the locker button before it disengages (sometimes it takes some movement) it’ll stay engaged, but if the teeth are lined up just right the locker will disengage.

 

I left it engaged once it finally went it. I was just trying to gauge whether or not to try to lock before getting into a scenario where I need it. Also was wondering if just locking it randomly from time to time would help with the process (thinking maybe the actuator is sticking from not using).

 

Locking it a couple of times a year is enough to keep it working.

 

Just Do It...... But find some loose gravel first!