locking hubs not engaging?

[feelblades1]

ok, i have run into another problem, I don't think my truck is locking the hubs into 4x4. The transfer case is engaging but when i lock my hubs in and turn my steering wheel hard to the left or right (going very slowly of course) the truck doesn't seem to "bind or jerk" i have not had it off road as of yet, (just got it friday) so i was wondering what everyones thoughts of what may cause the front diff to not lock in. any help would be greatly appreciated!

 

[hoe_nah]

Uhhh why would u try and make them bind? Thats asking for something to break

 

[feelblades1]

you don't turn the steering wheel to full lock, you turn it slightly while very, very slowly moving, when the front tires are pulling, the vehicle will bind, again, i have been dealing with 4x4's my whole life, if you don't have a lift to lift the whole truck up on, then this is the only way to be sure the front end is engaged and pulling.

 

[feelblades1]

ok guys, I just found 2 large vacuum lines coming from the intake on the pass side of engine and they are plugged off, would these possibly go to the front diff to engage the hubs??

 

[KidVermicious]

Four jack stands. Check to be sure the front driveshaft spins when you select 4wd - if so, check next to see if the CVs are spinning (assuming you're ifs).

If the drive and CV shafts are spinning, you can blame one or both hubs. They're easy to take apart and rebuild, if one is bad.

 

[feelblades1]

Thanks kidvermicious, I will def try that when the rain stops here in alabama!

 

[KidVermicious]

ok guys, I just found 2 large vacuum lines coming from the intake on the pass side of engine and they are plugged off, would these possibly go to the front diff to engage the hubs??

Is it an ADD diff? If so, the long side axle tube will have a vacuum actuator. If your truck has been converted to manual hubs, you need to lock the vacuum actuator in the engaged position.

If it's not an ADD diff, then your vacuum lines don't have anything to do with the 4wd.

 

[feelblades1]

not sure if it is an ADD diff or not, i will have to check that next time i work on it. The locking hubs do appear to be toyota, not sure though, this is my first go round with a 4runner or toyota period. I had an 89 jeep wrangler with auto locking hubs and it needed vacuum to slide the sleeves to lock the hubs. these are big vacuum lines and i think they may have something to do with the hubs. I will definately let you know what I find. I really appreciate the info!!!

 

[helo-mech]

It sounds like you have an ADD that was converted to manual hubs. Big actuator on the axle tube will tell you if you have ADD. Check these links. It talks about ways to "lock" the ADD tube. Like Kid said there is the option of replacing the ADD tube with a non ADD tube if you don't want to fix the vacuum issue or lock the forks in the ADD tube.

Toyota Tech: Defeating the ADD System - ORN

Also this thread has a lot of info on the ADD not working issue. The second page has pictures that show the "hose clamp" mod to lock the ADD forks.

ADD to Manual hub conversion help!! - YotaTech Forums

This is a good little read as well.

http://www.toyota-4runner.org/classic-t4rs/115286-manual-hubs.html

 

[feelblades1]

Thanks Helo-tech! I will definately check that out and report back!