2Low w/o dual transfer case with hubs locked?

[Devilmans Hand]

Hey guys

I'm looking for a way to switch from 4low to 2low on the fly on my 1986 4runner w/o adding a second transfer case and while having the manual aisin hubs locked.
I'm toying with the idea of putting an autolocker in the front IFS diff from a 1995 4runner with the factory 4.88s. I want to only engage the front diff with auto-locker when needed and to want minimize the stresses upfront.
An air locker is just too expensive right now.

I still have the ADD tube from the 1995 and I was wondering if I could use the ADD system to accomplish my goal of 2Low.

A cruiser buddy with a fj62 modified his electrical shifting system to get 2low, and i'm wondering if i can use or trick the ADD or other system to get 2low in the 4runner.

Also, I know on the fj40s and fj60s I can remove the shift plate and directly shift into 2low from 2high or 4Low. Can i similarly do the same on the 4runner?


any sharing of ideas or methods would be appreciated.

 

[Sam Stewart]

You could go with the dual stick setup. That way you control the 2/4 and H/L separately. You can only do it on certain transmissions I believe.

 

[Fast Eddy]

It will never be "on the fly" as there are no syncros in the t-case.

 

[snobdds]

There is no way with the ADD.

The best would be to twin stick it and leave the manual hubs.

 

[Devilmans Hand]

thanks for the replies.

I'll look into the twin stick w/ a single case.

 

[Devilmans Hand]

found this thread on yt that might be of use
2WD Low Range - YotaTech Forums

"I have a 1991 3vze pickup and use it for a lot of work around my property or gathering firewood. Which makes 1st gear in 2WD a bit tall. I end up using 4 Lo alot but hate how it binds up when turning.

I modified the electrical relay that supplies the vaccum to engage the front differential. By cutting the positive wire and patching in a wire that runs into the dash and hooking a switch up on the end. This allows me to put the transfer case in 4lo but have it act like 2Lo.

If you are driving along and want to use 4wd, a simple flip of the switch on the dash will engage the front differential. I did notice that you can't disengage the front diff without taking the transfer case out of 4wd first, flip the switch "Off" and then put the transfer case back in 4lo.

This allows me to have slow speeds without binding the front end but can still use it for my daily driver. Thought I would share my mod.

Justin"- 'JJMOSS99' over on YT


This is along the lines of what i was thinking for a "simple/cheap" solution.

 

[2ndGenToyotaFan]

If you found a front diff with the ADD, you could put that in, then plumb it with some vacuum switches to accomplish this...

I think I have a 4.56 gear, ADD front diff that I could be talked out of.....

 

[Devilmans Hand]

Thanks, but i have a full ADD diff with factory 4.88s waiting to be slapped in the 4runner.
I'll need to source the other components of the ADD system though.

Could I swap on my IFS Aisin Manual Hubs on the ADD axle tube so that i can still manually disengage the front driveline for highway speeds then trick the ADD into engaging/disengaging for 2wd Lo when crawling around? I'm thinking yes, but would like to check for any possible issues.
I don't think running an autolocker with ADD and live hubs would be a great combo.

Would anything 'interesting' happen if I were to run the hubs unlocked and engage the ADD into 4wd with the autolocker so that only the diff spins? I'm also thinking no, but...

 

[2ndGenToyotaFan]

Yes, you can install manual locking hubs on the ADD diff.

With hubs unlocked, and transfer case in 4WD, while driving, I would not recommend trying to lock up the ADD.

With hubs locked and t-case in 4wd, yes. With hubs unlocked and T-case in 2WD, yes...

But with the hubs unlocked, and the front drive shaft engaged, you might be trying to engage a spinning axle shaft to a non-spinning axle shaft.... And that might not end well...

 

[Devilmans Hand]

thank you sir.
I expected to have to stop before engaging anything.
Sure beats jumping out of the truck to work the hubs and is quite a bit cheaper and easier than twin sticks.

 

[2ndGenToyotaFan]

That's the safest option...