Locking Rear Diff 2015 Tacoma

This is my first post so please excuse my ignorance but I just bought a 2015 TRD Off Road with the locking rear diff. The truck was well used and has 217,000 miles but (no surprise) it runs strong and is in overall pretty good condition. One owner CA car so no rust and as I was examining the underside I noticed the rear diff has an almost new sticker like the diff was fairly recently replaced. It should have a rear locker but I'm not sure how to tell by just looking.

The part number looks like A0 202 0129150824 SKY. I've spent the last hour looking up the part but no luck. My question is, How do I tell if it is indeed a locker as I don't have any off road areas to test it nearby? Are there visual clues? Does the part number (?) help identify?

THANK YOU

Any help greatly appreciated.

 

Post a photo of your differential taken from the driveshaft side.

 

There should be a wire harness coming from a silver or black actuator on the rear diff and a push button to the left of your steering wheel. The button is title “RR DIFF LOCK”

 

It should have an actuator on it that looks like this.

 

Thank You and Will do. Let me figure out how to post pics.

 

Definitely has the button left of the steering wheel. Gotta climb under and check for harness etc.

 

Awesome I will check ASAP...

 

Looks just like the pics you posted - THANK YOU, THANK YOU, THANK YOU so much for quick and informative help!!! Hopefully I can contribute some day.

 

No problem.

Make sure to actuate it and your 4wd system every few months or so to keep things working, note the locker will only engage in 4Low on 4wd trucks.

Also check the vent hoses on all 3 actuators anytime you are under the truck doing maintenance etc, if they become detached the actuators will get water and dirt in them and stop working.

https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

I have to be in 4 lo before the locking diff will engage and your 2015 is probably the same. I don't understand why, makes no sense to me but that's how Toyota designed it. Every other truck I'm aware of will let you lock the diff in 2wd or 4hi. Even the 2wd Tacoma's will engage in 2wd.

You can engage 4lo sitting in your driveway and move the truck back and forth to see if it engages. Won't hurt anything as long as you're not trying to turn corners.

Another quirk is that it may take 20'-50', sometimes more before it engages if at all.

My wife was the primary driver of my Tacoma from 2016-2020 before we bought her a newer car. The Tacoma became a 3rd vehicle and for the last 5 years I've driven it daily locally. For longer trips I have better options. After 4 years of non-use the locking diff simply would not engage at 1st. I started driving it again just as the Covid lockdowns started. I couldn't do much anything else but it was turkey season and I hunted almost every day. Which meant a 5 mile one way drive down a gravel road every day for about 2 months.

I drove that road in 4 lo and just kept trying to lock and unlock the diff. After a few days it started working sporadically. By the end of turkey season it was working consistently. As they say, use it or lose it.

If yours doesn't engage at first don't give up too soon and start throwing parts at it

 

I had the same problem with my 2007 Tacoma, it often required rocking back and forth on a trail to engage. It was very clunky and abrupt as well. I have an Eaton/Harrops E-locker in my 3rd gen that engages 100% of the time and is completely silent.

 

Thanks again for all the help and tips. I've only had the truck for 2 days but as soon as I see some dirt it's game on to test all the systems.

 

It's probably liability. Toyota doesn't want to be found responsible for damage caused by people driving at high speeds on slippery surfaces with a locked rear diff.

 

I got a chance to test all the systems today and everything seems to be working fine. I got the rear locker to engage after a couple of tries and was on a very quiet piece of pavement so only went 10 - 15 ft. with the lockers on. I know, not too smart to engage on pavement so was very gentle and could definitely tell it was engaged. I went to turn it off via the dash switch and they wouldn't turn off. 4WD high, 4WD lo, neutral and back and forth, all while parked. I thought I was screwed as I was a couple miles from home. I then, in 2WD high, I just drove off and the locker turned off áutomagically'. I'm assuming this is how they are designed to turn off? At a pre-set speed?

 

^^^Yes, something like 15 or 20 mph it disengages automatically (I think).

 

The locker has to be disengaged first, truck must be under 3 mph and you may have to weave back and forth a bit.

To get in and out of 4L truck must be under 3 mph, trans in neutral (A/T) or clutch fully depressed (M/T). If conditions aren't correct it will beep and you will need to move the knob back and try again.

 

No. The transfer case and locker both (individually) require their mating components to sync/line up before they can engage, then if they are under load or are bound up, can require some back-and-forth type movements to fully disengage.
If you follow the proper sequence (stop the truck, neutral, shift from 4LO to 4HI, back to drive) it is possible the locker doesn't disengage immediately.

No. This is wrong information.

 

OK, so a LOT to learn and thanks for the info. May not need the locker for a long time but good to know how it engages/disengages and why. Is it simply a bad idea to drive off like I did in 2WD HI? Or were the components simply aligned properly for the locker to disengage?

 

Nah, you're fine.

Generally the truck will wait and unlock the diff when it's safely able to, rather than forcing it when you press the button. You're fine.

edit: But sometimes the transfer case won't shit out of 4LO when you tell it to shift to 4HI and it'll beep at you, so go back to neutral and 4LO and repeat the process.

 

Thanks and appreciate the encouragement. Yeah must admit I'm really ignorant about such things and haven't had a 4WD truck before. I've also have a 2WD 2003 1st Gen (V6 195,000 mi.) with zero tech and yeah have to admit I was a bit panicked with the locker 'stuck' on and miles from home but it's all good and thanks again for the info.

BTW I was just reading the manual and of course there's no real world info i.e. you might to rock it back and forth etc. Just some really simple instructions as if the system going go by the manual every time. Anyway thanks again.