Successful locker anytime mod?

So, has anyone successfully done the rear locker anytime mod for a 3rd gen? I see posts about it but it doesn’t seem like there’s been a solution.

Asking for a friend

 

OVT will be doing this as part of their tune I believe

 

I saw nothing about that lol, that’d be amazing though. I guess I’ll shoot mat an email after he sends me my new tune files

 

That has not been stated. Matt has only responded that he is aware that this is something the community would like. There are hesitations due to the possibility of something getting broken if locked at speed or other circumstances.

 

Having a locked diff at speed isn’t the issue, it’s trying to turn at speed with a locked diff. The wheels wouldn’t want to let the truck turn

 

Locking the diff at speed is what I said, not speeding while the diff is locked.

I.E. engaging the locker while moving.

 

No complete installs yet.

Matt @OVTune asked what people are interested in in this regard, but is 'not making promises, just looking at the data'
https://www.tacomaworld.com/threads...-alpha-release.495735/page-1907#post-19741572

I looked into it, havent completed building any actual test hardware for anytime lock. Note, initially I was trying purely to only mimic the Toyota ECU output to the locker, to minimize risk that anything gets cooked, etc. My last thought for OR and Pro models is that I would recommend building a 4Lo spoof box, that would make the truck think it was in 4Lo, in any mode, and therefore allow diff lock.
https://www.tacomaworld.com/threads/rear-diff-lock-anytime-mod-3rd-gen-development.537810/

We have since had some bench testing of a take-off e-locker (thank you @traumahawk for doing bench testing). Based on his bench testing, I think a simple power resistor to knock down 12V, and a light to display lock status would work. But it is still significant butchery into your 4WD harness (for OR or Pro models), or building your own plug-and-play harness.
https://www.tacomaworld.com/threads/2017-e-locker.585669/

 

I need it. I am installing at Tacobox and so I need it so that I can have the Tacobox in Lo and the factory case in high and still have a rear locker.

......or yank the factory locker out and install an ARB. That would work too.

 

@OVTune

 

You going to/willing to hack your 4wd harness? Willing to do some medium level wiring work?

It hasnt been tested, but I am 95% sure we can design an electromechanical solution (just splices and relays) which will spoof the ecu into thinking you are in 4lo when you are not. Advantage there is that it also makes atrac or mts available and disables abs.
It's going to take some hacking, or building your own plug and play harness probably. (We believe located connectors from japan for the ecu make and female).

But this solution requires some time to stop, engage spoofer, and switch truck selector dial to 4lo.

Alternatively, just put 12v with a power resistor (see other thread for resistance) on that factory locker. This will let you engage it anytime easily, but get no ecu safeties and no abs disable. (Also hacking with this method although less, or build your own pnp)
If you go this way, what's the worst likely outcome... burn out the factory locker and replace with alternative)


Make sense?

 

It does. Between the two option, I think the 12v power resistor sound like the simplest approach. I would say that I have strong average skills in electrical components. If you would be able to guide me with detail on the process, it would likely be some thing that I would give a try.

To be able to have the locker on when the factory case is in high but the Tacobox is engaged would give me the locker option when in 4.7:1 low as opposed to only single or double low.

Is the 4wd computer removable to work on inside? Its 5* here and I am currently sans garage.

 

I don’t understand what the big concern about having a locked rear and turning or at speed etc. my old DD was an 85 4Runner with 35s and a welder rear end. I drove it through heavy rain on the freeway, mud slicked roads, dry pavement city turns, wet and dry off ramps at speed. I had the rear end slide on occasion, due to me purposefully punching the skinny pedal to do so. In 8 years with a welded rear I never broke a shaft or ring gear or anything else in the rear. Yes my tires did wear rather quick but other than that I don’t see any problems. Is there something that I don’t know about or didn’t experience that is of great concern?

 

You can pull the ECU, but you don't need to. (wont do you any good).
So this is basically what @traumahawk started working on. (he is installing a takeoff OR/PRO locker on his non version, so he has had it on the bench and has been doing some bench tests that were supremely helpful, because I am not smoking my locker on my truck)
https://www.tacomaworld.com/threads/2017-e-locker.585669/page-4#post-19768438

First 2 questions.
Do you want to to use the existing locker switch (a bit harder to wire up), or will you be using a different switch or a 'switch pro' or something (a bit easier)? (note, this version of the mod will make the ECU NOT EVER used to provide power to the diff. It will be only you. All safeties on locking will be on the operator)
Do you want any feedback from the internal locker to light up a 'locked light' or anything similar? (note, truck normal lock light will NOT be functional with this version of the mod)

Instructions here will need to be adjusted slightly depending on the answers to these questions, but this will give you an idea. What I am going to say here will minimize the effort, which will still require alot of wire routing, etc.

First, need to get truck side connectors for the rear diff. You can cut off your own if you want, or buy new ones from toyota (probably about $20). If you cut off, take it inside and do 90% of the wiring.

Build the harness. For the simple non-factory switch, it will consist only of 12V switched power (good for 4-5 amps at least), a 100W or bigger power resistor that should be bolted to some metal for heat dissapation, and a big flyback diode to relieve the current from the lock coil (inductor) when turning off. If your switch isnt good for the current, will add a regular automotive 12V relay. This harness can be built on the bench, and really isnt that complicated.

On the truck, disconnect the lock switch connector on the diff and leave it open (so ECU always thinks diff is unlocked. If diff is locked when ECU thinks it should be unlocked, throws codes).
On the truck, disconnect the lock coil connector on the diff and put a power resistor on it on the truck side of the wire (think it was a couple of ohms, dont remember from my head). This will make the ECU think the diff lock is still hooked up (otherwise it throws codes on engine start).

Install your new harness and route it in the truck. Hook it up to power and ground. Hit the button and the diff will lock. (Note, this mod as described does not send the high voltage pull in, and lower voltage hold in currents. Just a trade-off between the two. Diff seems ok with it).

Here is a VERY poor schematic i drew while waiting for a connecting flight a few weeks ago, but it should give you an idea.



Now, if you want to use the overhead button, will need to add a latching relay, and access wires for that overhead button. A bit harder but not ridiculously harder.

 

https://www.tacomaworld.com/threads/2lo-plug-play-harness-discussion.592035/ ?

 

2lo is nice for when you need more speed control but not necessarily traction. Like backing a large trailer, long downhill decent where you better use engine braking.

Locker anytime is when you need traction. I would just like to be able to use in 4hi, traction and a little more wheel speed than you would get in 4lo.

Edit: I want both options. 2lo and locker anytime.

 

I have no concerns about 2hi locked or 2lo locked. I just want to be able to angage my locker when I want to be able to engage my locker.

 

We already have F12 and F13 connectors and I believe I have found all 3 of the other connectors you are talking about. We could probably do this like the 2low mod, but like you said the indicator lights on the dash would not function.

 

Yeah but it would be an indicator light NOT being on when it should be on as opposed to being off when it should be on. I can deal with that easy peasy. You sound like you are interested in making this happen. Id love to help both of yall however I can Im just not sure how much that will be. But Ill try.

 

Answer #1: Im not necessarily feeling the need to keep the factory switch. With the aftermarket selection of switches that look factory, Im ok moving it. No big deal.
Answer #2: I would definitely prefer to have an indicator light. Its pretty obvious when you dont unlock it but it is easy enough to install for the amount of extra set of peace of mind you would have.

Do you have part numbers and vendor for the power resistor and/or "big flyback diode"?

Are you sating youre close to making this work?

 

Care to clarify this statement? You said the same thing twice with different words the way I'm reading it. I think I agree with you, maintaining the indicator light would be nice. Unfortunately I'm fairly certain the instrument cluster communicates over CAN for system status signals, so spoofing that will not be trivial. The next best solution is what @BigWhiteTRD posted above and adding your own light somewhere. Most of the push switches have separate leds that can be used as the indicator.

The resistor is easily found on Amazon, or any electronics supplier. If I put a kit together I would not get cheap Chinese ones even though I will be using them for my first 2lo harness. The diode can be any 1N4001-1N4007 or similar. Again, off the shelf jellybean components.

I am not stating I'm close to getting this work. Just saying that what @BigWhiteTRD described above makes sense and *SHOULD* work. You are basically taking 100% manual control over the locker. I do not have a locker on my truck so I have no way to test. If someone wants to be the guinea pig I can see about putting something together.

If we wanted more sophisticated control (high voltage pull in with low voltage hold) it can be done with a little added effort.