Phillip Allen

trying out the 4wd on my new to me 91 4runner v6. transfer case goes into low and hi, but the light in the dash doesn't come on and the front diff doesn't engage. any ideas?

Chaser Johndoe

auto hubs or manual hubs? t case cable good?(if equipped) axle disconnect work?(if equipped) auto trans or manual trans? (yes it matters on what type of t case you have)

Phillip Allen

Manual transmission, auto hubs, not sure on the rest. Don't think there's a cable or disconnect.

wyoming9

iTrader: (1)

I think you mean to say you have the ADD system.

Then maybe someone just removed the locking hubs and bolted on drive plates

Was there a reason you didn`t check this before buying ??

Like maybe it came in a big box??

Are the electrical and vacuum parts installed on the truck??

Chaser Johndoe

could you get add with a manual? I've only seen them on auto equipped yotas. if he is supposed to have lock outs that means no disconnect on the axle. if thats the case means the t case has issues.

scope103

First figure out if you have ADD (Automatic Differential Disconnect, not the other kind). Does your front differential look like this? (two vacuum lines, and wire to a switch)


The switch is what operates the light; you put it into 4wd at the transfer case, a switch in the transfer case works a pair of VSVs on the right apron (under the hood), which switches the vacuum, which engages the ADD, which THEN closes the switch and turns on the 4wd light.

millball

Manual tranny trucks were equipped with ADD too.

My '95 5 speed Runner has ADD, but I installed locking hubs as well, to stop the front half-shafts from turning when in 2WD.

RJR

ADD was available on both manual and auto transmissions, starting in 1990.

Phillip Allen

really appreciate your input guys, will take a look at the diff when the snow melts. lol