Has anyone here "Defeated the ADD System" on a Toyota?

kpick

New member
I just picked up a new to me 96 t-100 4x4. (3.4l & auto trans)

The truck has a few problems, one being it will not engage into 4x4.

After a lot of research, it seems most likely to be the actuator, ADD relay or ADD switch.
I really do not like the ideal of ADD (Automatic Differential Disconnect). It works on vacuum lines and electronics. I would much rather have manual hubs.

After even more research I came across this article to completely bypass the ADD (Automatic Differential Disconnect) system.

http://www.4x4wire.com/toyota/tech/add/

It seems just a little too good to be true.

Has anyone here actually done this? Anyone have an opinion?

I guess my main questions are:

1. does it work as it should?
2. Do the dash lights still show "4x4 on"?
3. Any real downside?

Thanks in advance,
K
 

97kurt

Adventurer
I actually just pulled my front diff out and removed the actuator to prep it for shipping this morning. And yes, it looks that easy. Actuator is on the passenger side, 4 bolts and its out, you can engage 4wd by sliding the collar over. As the collar moves over it presses an indicator switch which turns your 4wd light on. I nearly did this mod when my actuator would not operate in cold weather.

And as Aikane said, if you get an electric actuator out of a newer tacoma/4runner it will bolt right in. Wiring it on the other hand will be another bag of fun.
 

1911

Expedition Leader
Yes it works, though later models use an electric motor instead of vacuum to move the shift fork.
 

Greybeard

Geezer
The 4X4Wire information is spot on! I just did the mod on my '90 4Runner (with changing out to manual hubs as well) and it works great. I was concerned that the 4x4 light would burn continuously, but it only comes on when the transfer case is shifted into 4x4.

Dennis
 

TangoBlue

American Adventurist
Yes, I defeated the ADD system by doing this...

CIMG1010.jpg
 

Forum statistics

Threads
185,530
Messages
2,875,572
Members
224,922
Latest member
Randy Towles
Top