ADD Switch

[541joseph]

Hey guys I looked and found stuff on 3rd gens but not for classics. I want to have 2lo sometimes so im not putting a strain on my cv shafts around tight turns on the trails. has anyone done this and is it the same as the 3rd gens? blue wire off the transfer case going up to the front diff?

 

[92-SR5]

You need a twin stick to accomplish that. I don't know if they make them for v6 t-cases though. You would have to get an adapter for a v6 tranny to 4cyl t-case, then get a twin stick kit from trail gear or marlin.

Are you open in the front? If so, I wouldn't worry about straining the CVs too much. I ran a locked ifs front for a long time, I never broke a CV. You absolutely can't run them on dry pavement though.

 

[Footofgod]

Easy trick for 2LO 2nd gen: Swap in manual hubs, delete the ADD. With the hubs unlocked, put it in 4 low and you will basically be in 2 Low. Lock the hubs and you will be in 4 low. I drove all over Moab like this. rarely did I need to lock the hubs for 4 low.

 

[Hyde802]

FOG gets it!

Very common swap. All you need is some hubs.

 

[541joseph]

Right but all of those cause me to spend money and both over $100 typically. I know that at least 1 3rd gen guy added a switch it stop the add from in gagging unless he wants it. I'm good with wiring do I might get my fsm out and see what I can find. Thanks for your responses.

 

[Hyde802]

Your factory ADD is vacuum operated.

Good pictures of how the slide collar in your truck works.

Toyota Tech: Defeating the ADD System - ORN

 

[Hyde802]

So you want to be able to manually select where the slide collar is?

Got a link to the 3rd gen guy that did this?

Heres the vac lines for the add.

Edit: Watch for a deal on hubs. I just sold a set for $125 shipped.

 

[Footofgod]

Hyde gets it!!!! The ADD engages the 4WD via vacuum. There is no electric switch that can do this. 3rd gens do not have this feature. A simple set of manual hubs will give you 2lo. Watch Craigslist for a set. You can often get lucky and find a set for less than $75.

 

[541joseph]

Ok so I see now. But what causes it to engage when you put it in 4wd? Are there vacuum lines going to the transfer case? Sorry never looked at one of these transfer cases out of the truck so I have no reference of what's on the top side.

 

[541joseph]

http://www.toyota-4runner.org/3rd-gen-t4rs/145022-spinoff-thread-manual-d-d-switch-2.html
At one point they talk about 2001 and up being vacuum but seems like it would be the other way round. But anyway there has to be something to cause the vacuum to engage it wether its a valve or and electronic solinoid.

 

[541joseph]

Sorry guys for all the stupid questions guys. But thanks for your help

 

[fo' runnin']

Sorry guys for all the stupid questions guys. But thanks for your help

Not stupid questions at all! I was curious about this too, I'm glad you asked! Looks like it's just not possible on 2nd gens though... :/

 

[fourwd1]

There's a lot of confusion here.
The ADD system does operate using vacuum, but the vacuum is controlled electronically.
When you shift the t-case into 4WD it energizes a relay, which controls the lock and unlock vacuum switches, which control the vacuum to the actuator.
If you interrupt the wire to the "Lock" vac switch the ADD actuator will not lock the front axle. NOTE: when I say LOCK I am not referring to locking the differential, we are talking about the front axle shafts.
The wire to interrupt an install a switch on is either the light-green wire or the pink a/green stripe wire, I can't remember which is for the lock vac switch.
The two vac switches are located in the engine bay above the pass side wheel well. One is red and the other dark blue if I remember correctly.

 

[Hyde802]

fourwd1 ftw!

To take this a little farther.. You could weld your front diff, and run the front slide collar "open" to have a poor mans selectable locker (3 wheel drive really). Once the ADD kicks on, power will go to the drivers wheel and its go time!

:decision:

 

[541joseph]

[MENTION=1857]fourwd1[/MENTION] thank you this it want I wanted to know! Time to get out the old fsm and see what wire it is. And might even start on this today since I'm laid off now

 

[fourwd1]

One other point, if you do this, the 4WD light on the dash will not illuminate when you choose your new "2WD Low" range.

 

[541joseph]

Awesome thanks. For the info! Will defiantly try and get this done this weekend

 

[nevada]

fourwd1 ftw!

To take this a little farther.. You could weld your front diff, and run the front slide collar "open" to have a poor mans selectable locker (3 wheel drive really). Once the ADD kicks on, power will go to the drivers wheel and its go time!

:decision:

it would still scrub the inner tire, and put a lot of stress on the cv when turning. since the one(left side?) axle will still be engaged to the welded carrier.

 

[541joseph]

it would still scrub the inner tire, and put a lot of stress on the cv when turning. since the one(left side?) axle will still be engaged to the welded carrier.

Yes i agree but that wont happen for a long time and it would still be better then having a full lock.

 

[BoostedRNR]

Did you get this done? I've been thinking about this for a while. It would be really nice to have 2lo