Factory locker install on 16 sport

I was looking into a re gear and locker for my sport, got a few quotes for 5k+ before I came across a guy selling a wrecked '17 offroad in manual.

Figuring 4.30 gearing would be pretty good for what I need, and having a larger rear diff with a locker, I picked up the chassis for pretty cheap and figured I'd give it a shot.

So after swapping front and rear diffs for the re gear, and sitting off on the locker for a month or so I started looking into people that may have done it, found @traumahawk, and @BigWhiteTRD discussing just that. After bouncing quite a few questions off bigwhite, I figured I had a good handle on it, or rather, he just told me what I needed to do and I did it lol. (Pssst thanks again.)


So I ordered a harness, a few 3 ohm resistors and a pack of diodes, and a switch, and set to wiring.

We decided after traumahawk spearheaded the operation using one resistor that we'd try running two in parallel to minimize heat buildup, I took a small sheet of aluminum and attached the resistors and bent so I could mount in a way they'd be elevated from the frame slightly. Since I had the whole chassis i also had the wiring loom/pigtails from the axle itself, so I attached a flyback diode to the locker coil wiring courtesy of big white, cause I dont know wtf those do, (I ended up just butt connecting and silicone all the connections, for a minute I really wanted to keep the harness complete for whatever reason), and ran it through the resistors and into the harness lead. (Didn't really take pictures, I finished that on my lunch break so it was just get it done time).

Wired the switch to the overhead, that I'd Frankenstein'd up with a couple extra switch spots from the donor overhead. Locker seems to be working just great, gearing seems much better, also. When the locker is running, I measured the resistors at roughly 120⁰ ish after 15-20 or so minutes, haven't been able to do any real extensive testing off road, but I don't have any issue with confidence it wouldn't be just fine.

I did run the blue signal for the locker dash indicator, in case I want to run a led light as a bright, don't forget I'm on, indicator, but, maybe some other time. Hopefully all that is discernible, created on my phone, so its difficult to make it all look pretty.

Very much thank you to @BigWhiteTRD for all the help and patience, as I was very much Jon snow here.

 

Nice!

 

Sub'd like a mf

 

(OP) hit the majority of the electrical stuff... just some notes.

The resistor(s) are to lower the power going into the coil to the appropriate level that toyota applied to it. Can you put 14v on it and be ok? Maybe, I really dont know and havent heard any convincing proof that it is ok. So, I recommend the resistors. If you put straight 14v on it, that is double the power that Toyota puts on it.

The (2) 3 ohm resistors in parallel provide ~1.5 ohms.

Partial parts list (electrical)
(2) x 3 ohm (100w) resistors, wired in parallel

$10 Dahszhi Wirewound Resistor 3 Ohm 100W Aluminum Case Chassis Mounted Resistor - 2pcs

https://www.amazon.com/Yohii-Aluminum-HeatSink-Resistor-Chassis/dp/B07CVRL2S8/

Diode, decent sized power


Some connectors and other helpful data (if you pick up at the axle disconnect)


Connector I BELIEVE will attach to rear diff lock coil (if you dont have the axle harness)
90980-11156
low cost source = https://www.corsa-technic.com/item.php?item_id=663

Connector I BELIEVE will attach to rear diff lock position feedback switch (if you dont have the axle harness)
90980-11162
low cost source = https://www.corsa-technic.com/item.php?item_id=747

 

Thats awesome man.

 

Sweet!

Just a heads up on the silicone and butt connectors.
If you're just grabbing the closest tube of silicone you have sitting around the garage, make sure it's a neutral cure silicone and not acetoxy.
Acetoxy cure is the most common, and unfortunately gives off acetic acid during the curing process, giving corrosion a jump start on your butt connectors.
Easy check - If it smells like vinegar, it's acetoxy.

^ All that said, forgive my intrusion if you were already aware.
For all I know it may have been common knowledge to everyone but me until recently.

 

Woah

 

WHoaaa, nice! I think with my 5 speed 4.30 would be good for my 265/75's so before anyone regears... want to swap diffs?

 

Nice! I know that file on there! That’s me!
I gotta get rolling on my project.

 

I just need a little more, the least was the 4.88's, which probably would have been great, maybe overkill even for what I ever anticipate I'll do. But saving 3k plus was awfully, awfully appealing. And it was a matter of simply swapping axles, with the added benefit of the larger rear axle.

There's a good chance you're probably right, I just dont have the time to fix it at the moment. I appreciate it though, I was not aware of that, I may just solder them in the future or as bigwhite mentioned getting some waterproof connectors. I am really, really kicking myself in the ass for not cutting the other side of the truck, rather than just the axle side harness, but, kindsight and all that.

Is that where?? That really made it super easy for an idiot like me. Are you in the process as well? Is it just the two of us (traumahawk), that have done this so far? If so thats super neat.

 

Added connectors on my post above if you DONT have the harness attached to the rear axle... (preference is to obtain that harness and the mating body side if you can, with your replacement axle)

 

are the 3rd's swappable between the Sport and the OR?

 

Only if your sport is a manual.

https://www.tacomaworld.com/threads/2018-trd-sport-locker.686203/page-2#post-24213095

 

Can you share a link of a flyback diode that you recommend or a photo of one?

 

I am sure somebody will tell me that there are newer better parts (that are cheaper), but I think any old school power diode will work fine (as it doesnt need a real fast recovery or anything special).
I would recommend any 1N540X diode (such as 1N5400, 1N5401, 1N5402, 1N5403, 1N5404, 1N5405).

Just quickly glancing,

$7 BOJACK 1N5404 Rectifier Diode 3 A 400 V DO-201AD Axial 5404 3 amp 400 volt Electronic Silicon Diodes (Pack of 50)

https://www.amazon.com/BOJACK-Rectifier-DO-201AD-Electronic-Silicon/dp/B07NWJ514L


[Edit to note, I like the 1N5400 series because they are very robust, with very high surge current capability... It cant carry that much current at 60 hz because of heat, but is quite robust for turn-off surges. The 1N5400 is a thru hole package that will require soldering, other options are available ]

 

Are the OR and SportMT 8.75 differentials the same other than the locker or are there other internal differences?

 

If I recall correctly I don't believe the Sport has the 8.75, only the OR and PRO

 

The Manual Sport has the 8.75

 

In that case, I would think it is exactly the same (ring, opinion, bearing etc) minus the e locker