Help Needed - R Diff Lock Indicator Switch

I reread the last few posts and decided that I wasn't being patient enough with the truck. I headed over to a parking lot to drive back and forth and around in circles and whatnot - no dice, still getting the blinking locker light and it didn't seem to be engaging.

Previously, I was going 2WD > 4HI > 4LO, trying to engage the locker, getting the blinking light, and returning 4LO > 4HI > 2WD, before shutting off the tuck to reset the blinking light.

This time, I went 2WD > 4HI > 4LO, trying to engage the locker, getting the blinking light, but then shut off the truck while still in 4LO. When I restarted the truck while in 4LO, the locker light was not illuminated. When I pressed the locker button, everything worked as normal.

I'm guessing the on/off of the truck while in 4LO was an initialization of the new switch indicator by the 4WD ECU..? Anyways, it's working correctly now. Couldn't have done without you guys, thank you!

 

Quoting to make it easier to find this post again. This picture worth infinite number of words (and arm waving), when required.
(Diff lock feedback switch installation)

 

Can anyone tell me if all the second generation rear axles are interchangable? Not the complete differential... just the axles?

I need to replace the left side axle on a 2012 Baja Edition w/ traction control.

Also, the light is on and it won't go out after the differential was hit hard. Ideas?

 

I did a 5.29 regear this weekend and before I removed the 3rd member from the axle, I was able to pull this indicator switch out easily. I'm not sure how that could have happened, but I think Toyota will have to address that issue. All in all, I ran into the same issue with it not being installed correctly and had all time rear locker. I had it removed and bolted a plate to the insert hole to cover it up. Once my break-in period is over, I'll install it properly with the the carrier out. This thread helped a ton to resolve the issue, thank you guys!!!

 

I will say that I was skeptical of the cheater method in this thread, but it worked out very easily.

 

I dont understand the whole theory of tearing everything apart to put the sensor back in.. just to clarify the rear diff lock indicator switch is this (highlighted yeller):


all it is , is a switch with a ball on the end so it wont bind up on the shift fork shaft which is what is pushed in to engage the locker via the actuator motor assembly.. the switch is supposes to measure the 10k Ω when its not depressed.. when depressed it should read continuity. Since the switch has the 10k Ω at open, it allows the circuit to be completed and actuates the locker if button is pushed in the cab and other conditions are met (not traveling above 5mph, rolling straight, in 4wd or neutral for a/t..

Right? Im having issues with mine, abs light and diff lock blinks, and i get no power at the actuator.. both rear speed sensors have bad tone rings or seals (codes 33,34) and when i removed this diff switch with a wrench which was not too tight i noticed that the switch is just bad, not reading right…. Not physically broken tho.. but see no reason to take everything apart to put it back in..

 

Because we are discussing the 3rd generation e-locker in the BD22AN axle dubbed the 8.75". The exploded diagram you posted looks to be from the older 8" e-locker that Toyota used prior to the introduction of the version used in 3rd gen Tacomas. Totally different designs and systems.

 

Oh my baD.. i thought i read dude had an 04 tacoma or something.. sorry, thanks for clarifying though. Had me questioning life.. my fault..
I fixed the switch i was talking about though.. wanted 85$ for the thing. But i just soaked it in acetone and she verk.. now the speed sensors, some metal springy looking thing is loose inside the area where the tone ring is.. probably whats letting in the schmoo and why its magnetic schmoo.. lol.

this site has helped me tons though.. thank yall for that.. most times on the web you only get 1of 3 things, a foreign person who has zero idea how to speak english but some reason chooses to be on english sites, or you get derp tards who think they know everything and can do anything but cant answer a question one because of some reason or another or you get assholes who are just better than everybody and just talk crap about everything.. diamond in the rough to find a place where people actually know things on topic and take the time to help or at least try..
thankee much..

 

Man i got a diff lock issue and i cant figure out what to do to make it lock.. the actuator is fine, sensor/switch is fine. But the only way i can get it to lock is if i jack up the rear end off the ground and spin one wheel. If i spin any rear tire even just a tiny bit while both tires are off the ground it will spring all the sudden and lock.. the light will go solid and is locked also after i get it to lock once i dont have to spin a wheel and will lock everytime unless i put the rear end bacl on the ground, if i unlock it roll fwd or back with it off then it wont lock back until i do the whole lift the rear end thing..
What da hell could it be? Something aint aligned or i dunno. Both rear ebrake bell cranks are new and working now, rear abs work, no abs light, no check engine light, brakes are new and system is bled. Ive rebuilt the diff lock motor and had the switch out that tells the ecu if its locked or not and that works also, i recently changed the rear diff fluid which was nasty but was doing it before also. Theres no brake fluid leaks anywhere and i also flushed that entire system as well.. so i dunno what could be preventing it from locking..
Do i need to tear the whole rear diff apart and pull that pin that runs in to lock it or is there some little adjusting screw that i can turn to angle it up a little so it actually locks on its own?? Im at a head scratching moment and really want to hit it with a hammer.. sometimes that fixes stuff...

 

This a second gen?

Sounds like it's working perfect. Are you driving and turning the wheel a bit after you hit the lock button to allow it to line the clutch dogs up for engagement? That's what you're doing when you jack it up, should work on the ground fine.

 

No its a first gen. I really dont think its doing what it should be. The other day i tested it out by removing the actuator and manually moving the rack to the locked position and rotated tires to make sure was locked into place. I hit the lock button with actuator off but plugged in so it was in its locked position then mounted it in its place. I go and back out of the garage not even registering on the speedo and hear a loud pop. I was in a reverse right turn when it popped but never had any tire lock like normal trucks do when in 4wd.. it should have from what i know about how the stuff works should have made a tire skip when turning but just popped one time and nothing else so i hit the button again to unlock it and heard the motor do its thing to unlock it and had no diff noise or any issues after but sounds to me that what ever is locking inside the diff either isnt going fully into place and it slipped out or the things just stripped out inside. Although when i changed the old black nasty diff fluid not alot of metal came out on the magnet, except one little chunk of something about the size of piece of a small fingernail clipping.. guess my next move is to drain it and remove the whole damn stump to figure out what its problem is..
That switch on the stump though, is all thats for is to illuminate the lock light on the dash? Like to change it from blinking to solid when it locks? Because i know the switch works when pushed but i cant ever get the light to go solid. But was just figuring there was something else thats not letting it go solid since its not engaging right.. but could be wrong and it is engaging and just stripped inside or just a crap diff locker..

 

Is this true? That plunger sensor is not necessary for diff lock function, just indication? I am in the boat of my flashing locker light never going solid. However, with the truck in 4lo / neutral / the rear tires in the air / I spin one wheel and watch has the other side spins in the opposite direction / I then hit the diff lock and I am unable to spin one side with both sides off the ground, they still move in opposite directions, but only a degree or two. Would that indicate the diff is locked? I did have a regear done and the shop reinstalled the plunger with the carrier installed, who h clearly is not correct. I’m wondering though if it actually does still function correctly?

 

Yes, it's true. Yes, your test indicates the diff is open and then locking..... for now. The indicator switch is just for that, indicating. But the control system applies different power outputs to the diff lock based on that indicator signal. So it's not all working as designed even though it's not problematic, but it may become so. Probably should fix this when you can.

 

@ShimStack Really appreciate your reply and explanation - I wasn’t aware of the power outputs being tied in to that signal - I am definitely going to go after this correction.

I am a little weary to try and get the indicator installed correctly without disassembling the diff as others have done, so I already booked some time at a well-regarded driveline shop.

During this disassembly and reassembly, are there any critical seals that will get interrupted that I should have them replace vs reuse in the process?

Thank you for your help!!

 

@ShimStack is 100% correct, however there is another thing to note.

The ECU does monitor for a 'stuck' feedback indicator switch (both stuck ON and stuck OFF), and will throw a code under the right conditions which then disables diff lock operation until power cycling. That said, in my experience and using my pitiful memory, in general it does take a decent amount of driving with the diff locked (and the feedback sensor showing unlocked) to finally throw the code, but I did get it to do it on my 2017... (I think its alot quicker to throw a code for the stuck-on feedback indicator switch

The Stuck OFF is P17BB and the stuck ON is P17BC
Here is a couple of excerpts from the Service Manual for these just for interest sake... not that it is useful...

 

No. It's just drain diff, unbolt driveshaft, pop out axle shafts, remove 3rd member, pull carrier, fix problem, reverse process.

Axle seals should be fine and 3rd member uses FIPG.

 

@BIG white turd. Lol. Sry. Trd.. but that schpeal might be true for later models but my ecu is about as dumb as a calculator.. mine only has a few evap and o2 fuel trims that it has to think about over any time intervals.. no codes for the diff just speed sensor abs stuff..

 

Lol. Turd

 

Thank you so much for the help and explanation!

 

@highwest how did you put the wood? I’m trying to find it but cannot. The thread attached above didn’t help either.