Outer Limits 4x4 Board

ive got a 94 sr5 with shitty ifs and those annoying auto lock hubs,
a mate of mine told me that if i was to fit manual locking hubs and disconnect the electrical to the solenoid on the front diff, the cvs would stay engaged in the diff, and all i would do 2 engage 4wd is lock hubs and push the button,

was just wondering about anyone else who has done this and is this right?
i'm guessing that the solenoid on the diff has 2 a normally closed one, but if it requires vacuum to hold it on, this isnt the way 2 do it

my number is 0421 22 1865. name is rob, would appreciate it if u knew anything about it if u could give us a quick buzz,

cheers[/code]

Rob, you don't have auto locking hubs you have fixed hubs.

The 4Runner system is called ADD (automatic disconnecting differential).

The right axle is permanently locked to the wheel and the diff, whereas the left axle is only locked to the wheel. When you push the button, the ADD system locks the left axle to the diff via vacuum acutating a sliding splined collar etc and then you have 4wd.

It is common to remove these fixed hubs and fit freewheeling hubs as this allows the wheels to turn without also constantly turning the CV's, rubber boots etc. Its a straight bolt up and takes all of 10 minutes.

Unless you are expieriencing major issues with the actual vacuum actuation system just fit some hubs and leave it as is.

This gives you both scenarios. Whenever the hubs are locked you have normal ADD as it is now. With the hubs disengaged its not turning the axles, CV's etc when driving around town.

But be AWARE don't push the 4wd button while moving unless the hubs are locked first

thanx ozrunner

that s what i meant, i know the cvs r disconnected from the diff,
but i am having issues with the solenoids under the bonnet i think, if i dont swap the hoses over, it will disengage after a short time, one solenoid mustn't open fully, and isnt allowing enough vacuum flow 2 hold the system on, i will fit the hubs anyway, my mate has got some,

thanx for your input

You probably have a slight vacuum leak somewhere or the solenoids are leaking. Check all the small hose ends as they can crack etc. The solenoid sets are also cheap from wreckers

You can do one of 2 things....

1 - Buy a HILUX housing without ADD, strip your centre out and put it in the new housing. You'll need manual hubs and thats it. There are 2 wires to the FRONT of the diff, just bridge them and you trick the transfer allowing it to engage. The vaccum lines you can just loop in the engine bay and run a short piece to bridge them together.

2 - If you have solenoids playing up, i have 2 complete ADD housings that are in good nick with spare open centres for sale... both have been pulled apart and checked and everything looks great.


I've just taken route 1, and everything seems to be working fine. I haven't had it in the bush yet but testing it on the street seems to work fine.