Hi everybody, I have a 1990 Toyota 4runner 5spd and having problems with my 4wd. It wont engage and I took it to a tranny shop and he figured it would be the actuator on the front diff, which is a couple hundred bucks. Some friends suggested putting manual hubs to eliminate all the problems with the A.D.D. The thing is I talked to 3 people and got 3 different answers on how to change them. One person said to go to the junk yard and get stock aisan hubs of toyota and they should just bolt on and work, another person said i need hubs and a spindle conversion kit and another person said i need axles , hubs, spindle kits. So if i get some manual hubs from a toyota what do i need to do to switch from A.D.D to Manual Hubs. please help snow is here where im at,.. Thanks

 

SEARCH my young padawon....its covered alot..lol prolly like..once a week!

 

Permantly lock the front diff by looping the vac lines.

Then go get aisin hubs from a 86-95 truck/4runner, then remove your hub flanges and bolt on the hubs.

 

what do you mean loop the lines? do i have to take the actuator off and mess with the fork at all? thanks for all the info guys

 

Well, if you can get it to lock, then you can apply vacuum and loop the vac lines. So it keeps a vacuum.

Unless the actuator is broken. Then go get a used halfshaft and replace it.

 

Everything you wanted to know, but were afraid to ask: http://www.off-road.com/trucks4x4/ar....jsp?id=399612

Bottom of the article has all the how-to on locking the actuator. It's a simple job. As was mentioned before, check wabfab's site for a set of Aisins. Remove the old flanges (very simple) and bolt the new hubs into place. Might take you 45 minutes or so.

 

Installing manual hubs will NOT fix your ADD woes.

With ADD, your CV axles are always locked to the spindles via drive flanges, so there is a problem somewhere else in the system.

 

have you tried checking voltage at the vacum switching valve? Does the 4wd light come on when you shift it to 4wd? You need do to some diagnoses work. Could be your vacum line to the actuator is torn.

 

If you get around to installing some manual hubs later...
https://www.yotatech.com/forums/f125/

There is a few articles in the tech article section.

 

no the light doesn't come on, but the transfer case locks in when i put iti in 4wd, the guy at the tranny shop tested the vacuum and said when in 4wd it has vacuum going into the actuator but not out, so he said that the it had vacuum going to the actuator and the t-case was working so said it was the actuator

 

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

 

So if you know its the actuator, you can fix it. Right?

This goes back to my post. You cannot fix a problem with the ADD actuator on the DIFF, by replacing the drive flanges with HUBS. They are two different systems.

Either 1. replace the actuator, 2. lock it in all the time (people have used hose clamps, but I do not recommend that) 3. replace the diff with a non-add setup and do a manual hub swap or 4. Buy a Prius

 

im good on the prius.. but i found another thread and decided to go the route with locking the actuator fork in 4wd they used a hose clamp too( what do you recomend using?) and then puting manual hgubs on