Manual T-case and reduction box conversion

[rmack]

Decided to finally switch over to a manual T-case and crawl box on a 3rd gen Tacoma 2022 Off-Road.

Background - I have been wanting to do this for a while now. I picked up a 4runner (2022) VF2A manual t-case about a year ago. Since then I installed the RCLT and other stuff including rear disc brakes. Decided to pull the trigger on this over X-mas. I don't want the electronics getting in the way of 4WD and I wanted a lower crawl ratio which was 48.94 and is now 230.

- Electronics don't make 4WD fail unless it is specific to a device like the ADD, front/rear elockers. So all 4WD components are on their own wire harness.
- Lower gear ratio (230 is good for me)
- Triple stick - 2Lo or 2LoLo
- Minor or no console chopping
- Some kind of electronic indicators (Not fully done, working on spoofing the 4WD ECU in place of splicing wires)
- Anytime rear Toyota OEM elocker
- Get existing armor to fit with new configuraiton

TODO:

- Get rid of dash lights (ABS, etc.. after pulling the ADD and auto-t-case plugs)
- Fab a crawl box mount plate for more support

NOTE:

- You can install the NWF Trident Shiffters w/ a crawl box and manual 4runner t-case into a 3rd Gen auto tranny tacoma
- I didn't need a body lift, everything fit and cleared with minimal pounding on the under body. Technically I didn't need to pound on anything, but I did want to give more than a 1/2" clearance on the driver side drop t-case.
- The Auto-tranny cable shifter clears the 2WD output flang and drive shaft by a 1/2"
- If you want to use the ebrake location you don't have to cut any console plastic (but shifter design takes some work) (Otherwise you could use the front cup locations, but I want to keep these)
- Shifter design and install within the ebrake location (it can work)
- You can keep the ADD with a new wire harness, or you can delete the ADD if you wanted. I wanted to keep mine.
- Someone on Tacoma world has appeared to come up with a ADD/T-case spoofer design. I haven't tried it, but maybe I can get crawl control and track control back for 4WD. - https://www.tacomaworld.com/threads/3rd-gen-spoofer-development-for-add-and-transfer-case-actuators.841653/#post-30116283
- Yes there is more gear noise in the cab now, but I think I have a good solution to reduce it with EPDM material.
- No you can't just unplug the auto t-case and wire up the manual 4WD indicators and expect the electronics to work you need to spoof the ADD and t-case to get the 4WD CPU to not throw error codes
- The BAMF armor I have will cover all the way back over the new position of the t-case, I do not need to extend the t-case armor I have

If anyone has a specific questions about what I did, just let me know. I took lots of pictures and notes hoping it might help other people.

What the sifters look like right now

[rmack]

Under the truck

[rmack]

The shifter took the longest to get done. I might make some minor modifications, but everything is working. The crawl box shifter linkage comes up right under the automatic tranny shifter plastic housing. Because of this some cutting is required of the plastic housing and a shifter design was needed to fit under the plastic and then wrap around to where the e-brake was located. Because the rear brake kit I installed no longer used the e-brake I decided to remove all of the e-brake components and run the shifters to this location. By doing this I removed the need to cut or modify my center console.

[rmack]

The shifter design needed too:
- Not bump into each other for free movement and prevent one from popping another one out of gear (to be able to shift)
- Clear the auto-tranny shifter plastic housing in multiple locations
- All the auto-tranny plastic housing to still be stable and strong
- Allow all shifters to come out the e-brake location without cutting or modifying the center console plastic
- Make use the of the e-brake boot cover
- Still be able to cover the hole made in the floor

[rmack]

To cover the floor I used the following material (below). Note, I had to cut the floor more than I wanted because the NWF trident shifters had to be installed after installing the crawl box and t-case. So the shifters were install through the cab onto the crawl box. I wasn't able to install everything together as there wasn't enough clearance to get the crawl/t-case into position with the height of the NWF shifters in place. I could have cut the hole back further, but I didn't want to cut back any further and still make the plastic housing as stable as I made it.

- https://a.co/d/9nkYEGH - Silicone to cover the hole. I used the small one.

[rmack]

Triple stick. I decided to go with the NWF trident because...
- I wanted to make one hole
- I needed body clearance at the t-case
- I didn't want cable shifters
- I wanted 4Lo, 2Lo, and 2LoLo (want to take out of 4WD when I need to turn as the RCLT kit I got the turning radius is worse than stock, but I didn't mind this) The ADD switch could also be used. - Update - ADD switch works better than trying to drop out of 4WD.
- I wanted neutral while also in 4WD (but not at the reduction box)
- NWF has good customer service
- The design was pretty good including preventing oil from coming up and out of the stick shift area
- I could add a breather to the crawl box through their crawl box shifter

Note: I closed off the crawl box from bleeding oil into the tranny bell housing area as I didn't want to to seal the crawl box to the tranny
-- No oil will leak from the input shaft area, the lower hole, nor the shift rod area. I closed this all off with RTV gasket seal
-- I haven't seen any leaks yet from any spots. - Update - Still no leaks

- At the time I didn't know their shift rods are stainless, so I did end up welding stainless to mild steel, but I don't care about rusting in the cab.

When pulling the t-case apart I did make the mistake of popping the syncro keys out. I came up with a pretty good solution to putting them back in.
- Pull the shift fork up enough to get each key in
- Put a rubber band around the area where the keys go
- Initial put the keys in with the rubber band holding them in place
- Push the top part of the keys in and slowly push the shift fork down
They end up popping into place and you can cut the rubber band off after

[rmack]

Here are some general things I did that helped or should help over the long run.
- After taking off bolts I ziplock bag them and mark the bags with where the bolts go
- I didn't assemble the crawl box and t-case initially, instead it is easier to lift only the crawl box to figure out installation. I did this multiple times and it is way easier to move around and install to check dimensions.
- I taped the back of the tranny to keep dirt out
- Figure out the center of the hole position for the shifters from under the cab drill the center hole then cut what you need from the top so you don't cut all of the auto tranny shifter holes as you need the forward drive side bolt location
- Don't assemble the new tranny seal and coupler until you are ready to install the crawl box and t-case, makes it easier to lift the crawl box in and out while checking dimensions
- Pack the input/output shafts with Swepco 101 Moly grease to prevent fretting of the splines - https://a.co/d/fAp725E
- Use a good gasket sealer like Permatex 85080 Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker - https://a.co/d/epY8nDh
- Mark bolts with Tamper Proof Torque Marker as you torque - https://a.co/d/0KCOEZj
- Take pictures of how something was before you take it apart, example cutting and splicing wires
- When splicing wires cut one at a time, splice it, and then move to the next one
- Always create templates before cutting and cut as little as possible first
- Getting the front drive shaft out required me to remove the t-case first, but after lengthening I could install the t-case then the front drive shaft
- Exhaust reroute - put couplers in to make it easier to remove the exhaust to get to stuff easier in the future
- Pull the 4WD CPU fuse before turning on the vehicle
- Plug the lower right crawl box bolt hole with RTV so it doesn't leak oil (plug as in the back of it so you can still get the bolt in, don't close it off)
- Put anti-seize on flanges before bolting drive shaft back on
- Paint body hole areas, then fill the spaces between the metal with hi-temp resistant silicone glue (I did sand down the cut edges, but rubbing the silicone glue helps prevent you hand from getting cut while installing the shifters)

[rmack]

Anytime rear locker now setup with stock elocker using an Eaton universal wire harness and connected to my 8-switch panel at the dash.

To prevent anyone from kicking on the lockers (front and rear)

• Fuse under the hood need to be on
• Power on the switch panel
• Press two buttons for each locker to turn them on

[blackdiamond]

This looks to be really well thought out.

I have twin stick on my '89 4Runner and will be interest to see how much success you have getting the t-case out of 4wd when you're trying to turn. I suspect that you will have more success disengaging the lockers.  I am very rarely able to disengage mine, but it tends to be easy to engage making it possible to cruise around in 2low and then engage 4wd when it's needed.

[rmack]

I appreciate the comment, thank you.

I will be going on a 150 trail run to Box canyon near Florence next weekend. I will try going in and out of 4WD while trying to turn. I have a feeling it will not slip in/out very well. When this occurs I can also turn the ADD off via its switch, and I can turn the front elocker off with the switch. I will let you know how this works out for me.  I am able to drive and change in and out of 4WD easily. I have tried going 40MPH shift into 4WD and then turn on the ADD with no issues, and kill the ADD and shift back out. No issues shifting into 2Lo at a stand still. Anytime rear elocker functions as desired with lots of testing.

I just finished up padding the floor board under the console and final touches on the boot. I am also in the process of building a 4WD ECU spoofer and creating a write up on it.  I will share it here once that is done.

Here is an image of the shifters and boots now that this part is done for now.

[rmack]

Here is what the shifters look like in Lo-Lo...

[rmack]

I also just got done getting my armor back under the truck. I have all BAMF armor. The stock BAMF armor needed to be modified to get it to fit under the truck.

First modification was cutting the sides down and one bolt post cut on the front armor when the RCLT LCA kit was installed.
Second modifications were to the rear T-Case armor to get it to fit with moving the T-Case back for this effort.

Here is the rear armor cut.

[rmack]

Armor...

[rmack]

I still want to build something to support under the crawl box. I bought a T-Case mount, but I am still thinking about how I want to mount it. I want to be able to still get the armor on and off easily and be able to pull the crawl box and T-Case easily. A new cross member will get in the way of the armor I have. I am thinking about welding an extended stand off the existing tranny cross member. This would most likely work if I cut some of the armor up to make this fit. I am just not sure about being able to clear taking the crawl box and T-Case off without having to drop this cross member? Going to think about different designs... I will post something once this part is done as well. Cheers

[rmack]

Observations...
* LoLo ... will eat brakes if trying to hold still for too long. Shifting into neutral appears to solve the problem while braking.
* Rear disc brakes helps with LoLo
* ADD over shifting out of 4-wheel into 2-wheel while turning, doesn't always want to easily shift out of 4-wheel(*)

(*) Any suggestions for shifting with double stick? I find I sometimes need to turn the engine off to get back from 4Lo into 4Hi so the gears are not spinning. I.e. shift into 4Lo while in neutral ... drive ... stop then neutral then can't shift out of 4-Lo otherwise grinding ... turn off engine then shift back into 4-Hi no issues.

[Ritchie]

I too, have an auto trans... I need to put mine in PARK to change from 4 low to 4 HIGH.