3rd Gen Rear Diff Lock Problems

I have a 3rd Gen TRD OR with 2 pedals. Have mainly used the truck for on road driving (commuting and other normal stuff), but I do occasionally take it off road on OHV trails, so I’d like to have the off-road equipment it shipped from the factory with, actually working.

Since I purchased the vehicle, the rear diff lock has never once engaged for me. I’ve tried it in all different environments and scenarios numerous times throughout the 26k miles I’ve driven it.

I’ve tried very slowly rolling forward and backwards in 4Lo as other threads suggest, while on loose rock and dirt (to ensure I don’t hurt the drivetrain). I’ve tried sitting for minutes in N while the indicator light blinks both on dirt and just sitting in a parking spot on pavement. I’m following pages 300-304 of the manual to the letter aside from not actually needing to lock the diff given the various circumstances I’ve tried it in - (I just want to know it actually works if I ever do actually need it).

I’ve tried the stealership who lectured me in writing on putting the truck in 4Lo and waiting for that to engage before using the locker. I hate to say it this way but I can read. I’m following exactly what the manual says to do. I even got the truck to generate a warning (pictured) on one of my locking attempts, before taking it in. Didn’t seem to phase the dealership.

Any help from the group here would be appreciated. Might just have to try the dealer again while this thing is under warranty.

 

So did the dealership confirm they got the locker to engage? If so I'd make them show me and see exactly what they did.

 

That’s what they claim. I could go back there I guess and make them show me what they did to lock it. Seems like they put it up in the air to make it happen which to me isn’t a realistic test.

 

Make sure it’s locked in 4x4 first, then put in neutral, next 4lo make sure it’s fully locked in, no beeping or lights flashing, last push diff loc, may have to turn steering wheel back and forth while backing up and pulling forward slowly. If this doesn’t work you have a problem with actuator.

 

Done all that but I could try moving it again. The warning above was actually generated when I was pulling forward slowly while turning the steering wheel. I think it’s an actuator problem but seems it’ll take a bit of convincing at the dealership for them to repair.

 

Just do each step slowly and make sure it actually goes in for each step, then go from there

 

Drag a tech to a dirt parking lot. As long as it can break traction on ground, your safe.

It seems rather lame they would chalk up an actual warning dialogue as lack of understanding the correct procedure.

If you can't get them to play along, you don't want them wrenching on your rig anyway. Find a better dealership!

 

The turning action is what allows it to lock. I know you said you know this, but I cannot emphasize enough that you need to be turning slightly.

After a few actuations of the locker, its easier to engage for me. The first 5 times I couldn't get it. You need to wait at every step. Neutral for 4LO. Let it click and engage and then shift into drive. Then lockers. Then go forward slowly and turn.

When did you get that error? Getting a 4WD error is pretty easy to do. Did you get it after shifting into 4LO? Or were you fully in 4LO and engaging lockers?

 

I noticed mine took more effort to engage after I hadn't used it for a while, so I'd guess the same logic for regularly engaging 4wd probably applies to the diff lock actuator as well - use it periodically to keep it lubricated and from locking up.

Usually to get mine to work I have to roll forward and back quite a bit, sometimes with just a bit of steering input, before the diff will lock, quit a bit more than when just engaging 4Hi on the move.