I have a 91 with auto hubs and I can't shift into 4wd on the fly. The manuall says: "If it doesn't shift easily into 4wd, come to a stop and then shift." This seems kinda odd that it is kindof soposed to shift on the fly if it want's too. Anyway, I always have to stop and I was wondering if the other guys with this setup have to do the same. (By the way, shifing out on the fly is no problem).

 

If it's the ADD system, it should shift into 4HI up to like 35 mph. I usually come to a stop to shift into 4LO. If you do have ADD and it won't shift into 4HI while moving, you might want to have it checked out...

 

You might wanna check all your hoses and things of that nature...mine will shift in and out up to 40mph...but I rarely do it at that speed, if I feel like I need to I just slow down to about 30 and do it. I always come to a complete stop to shift into 4L though.

Fink

 

switch over to manual hubs. you'll be glad you did.

 

Do you have auto hubs or ADD? If you have auto hubs you most certainly cannot shift on the fly.

 

What is the diferance? I'm not sure which I have.

 

i've got auto hubs and i can shift on fly..like others said, make sure everything is sealed and i guess working proper

 

By the pic on your page "the oldest pic" you have ADD hubs not AUTO hubs.

 

Ok, so ADD hubs, so that means I should be able to shift on the fly?

 

Honestly I do not know. What it does mean is that there are no clutches, springs or other things to break in the hub. An ADD hub is a simple drive flange that is always connected to the axle shaft.

 

i dont think any 2nd gen runners came with true auto hubs. If you try to shift into 4hi and your add is not working you probally will hear the sound that it makes when you try to shift without the clutch.

 

I don't know, it just feels solid with no grinding. I have never really pushed it hard so I don't know if it would start grinding but if I have presure on the shifter while I come to a stop it drops in as soon as my wheels stop COMPLEETLY.

 

Just drive down a gravel road at about 25 mph, and yank that stick back. You'll never know untill you try it. I dont think your transfer case will explode if you just try it once. I have manual hubs, but sometimes i gota pull pretty hard to get it into 4hi, and push even harder to get it out.

 

You may need to let off the throttle, brake, or even apply a little throttle to release the load on the driveline in order to shift into 4H.

 

grip it and rip it

 

It also makes a difference whether you have synthetic oil in your transfer case and the temperature of the oil. 75-90w (assuming you have a manual tranny) gets pretty thick when cold and synthetic makes everything work better.

 

You do not have auto hubs, you have ADD.
Auto hubs were from '84 to '89.
http://www.4x4wire.com/toyota/tech/autohub/

They are bad bad bad hubs, stay away from them
They disengage on you when you back up on a trail.

Oooops, years corrected

 

Corey, you mean from 86-89.

I thought I heard of some people who have auto hubs on early 2nd gens though. Anyway, if you have ADD you should be able to shift on the fly up to 50 mph (according to my owners manual). Come to think of it, I wonder if the speed is different for manual trannies?

But again, if you have AUTO hubs, you cannot shift on the fly.

 

Check your tire pressure too. If there is much difference between front and rear rolling radius, the case won't want to shift.

Otherwise, the above tips about easing up on the throttle (or push in the clutch even) are good. I can shift mine into 4hi at any speed.

 

I know you can shift into 4HI doing 60mph, but Toyota suggests doing it under 55mph. As for low, they wnat you moving under 5mph. (That would be FIVE MILES PER HOUR). I have never had much trouble shifting except the first time after I installed my manual hubs, and plumb forgot. Glad I remembered before I broke something!!!!