98 front wheels won't engage when in 4x4

I have a 1998 Toyota Tacoma 4x4 Ext cab with 2.7, AT, manual 4x4 lever and manual locking hubs. The problem I'm having is when I engage the 4 wheel drive, the front wheels will not pull. The front driveshaft is turning but wheels are not. I don't know much about the Tacoma 4x4 system as I switched from Jeeps. Any and all information will be appreciated. Thanks all...

 

So what you are saying is that if you lift the truck up in the air, your front driveshaft is turning, but the wheels are free, and you can turn them by hand? I am trying to make sure I know what you are talking about exactly, because your Tacoma is all mechanical. There are no electrical switches or motors that could cause this problem.

I am assuming you have the manual hubs engaged fully.

 

This happened to me on my old '84 4runner. Couldn't figure out why I couldn't navigate very well in the snow, while 4-wheeling one day. Turned out that one of my free-wheeling hubs somehow got all gunked up with grease, and the mechanism couldn't move into 'Lock' even though the hub dial was completely turned to the 'Lock' position. Front wheels were not under power even though the front driveshaft was turning. One of those hubs might have broken, internally, but I've never seen that happen on an Aisin hub (just happens to Warn hubs, I guess )

Hopefully thats all it is. Otherwise, the diff is likely bad.

 

If there was diff damage hed likely hear a whole lot of grinding. A bad hub is more likely. With an open diff 1 unlocked hub = 2wd.

 

Yes, manual hubs are fully engaged. I did have a bad hub, or at least the part that locks that has the spring behind it. Is there any chance when I re-installed the new lock out this that I may have re-installed it wrong?

Can someone give me a list of things to check and I would also like to know the vacuum diagram for the 4 wheel drive system and all components. Thanks...

 

The outside being in 'lock' doesn't always mean the hub is locked in. If there is a broken part or an incorrect install it might not be working.

 

Did you test the hub after you put it back together? My money is on operator error.

 

Lock both sides, 4wd and tranny in neutral. Jack up 1 wheel and turn it. If the hub is engaged you should see the front drive shaft turn. Repeat on the other side. That should tell you which side you're having trouble with.

 

According you your first post, your '4 wheel drive system" is MANUAL. No vacuum lines, fuses, wires, buttons, relays, etc.

Sounds like your 'bad hub' is still bad.

 

Doesn't the manual systems still have to have vacuum?

 

No there is nothing else to engage. Turn both hubs and put transfer case in either 4hi or 4 low and that's it.

 

I'm having the same problem. But auto hubs. The drive shaft spins in 4wd. And in 4lo the back wheels are in Low.but the front wheels won't engage into 4wd. I'm thinking it must be some sort of wiring issue or vaccum issue. Can someone point me in a good direction to start? 2000 taco, stick shift 4x4

 

Here is a good read on ADD and trouble shooting it . Your truck has ADD if it doesn't have manual locking hubs ..... http://www.off-road.com/trucks-4x4/tech/the-automatic-disconnecting-differential-system-19259.html

I had a newer 4runner and think the ADD was electric and not pneumatic. I haven't had the need to check what the Tacoma is as it's worked like it's supposed to....so far.

 

When you turn a well greased hub (Asin hub) you hear it engage. Like a spring pops into place. The hub itself is extremely simple. Take them both apart clean and grease. Sometimes water and rust will stop them springing into place. It's that or your diff has blown up. Which would make quite the racket.

 

I fixed it with that guys write up, thanks so much man really appericate your help

 

The original poster started the thread in 2014, the fella that resurrected the thread has ADD...but good info for future seekers of this issue!

 

@tristen2000taco 's question was on the auto locking

I have ADD but would much rather have the much more reliable AISIN manual locking hubs and will be a future UPGRADE when I find some.

Helped a friend rebuild his AISIN's a couple of years ago at 500k+ miles on his 97 taco that he wheeled his arse off in and used this post on mud as a reference...... https://forum.ih8mud.com/threads/rebuilding-aisin-locking-hub-locking-hub-rebuild.149776/

 

I need to start looking at original post dates when I'm cruising along TW. Haha. I was referring to the original. Anyways..... Good luck!

 

When i was on the lookout for both my tacos having manual hubs was high on the need to have list! Along with the fully mechanical j shift transfer case too!! That kind of shit just dont need to have vacuum lines and fuckin electrical doodads incorporated into the system...

When we got the 4 runner we were lucky enough to find one (even the right color)to have a j shift transfer. It seems like they are pretty damn rare, it of course has ADD though dang it. But thats okay i suppose, i don't think the runner ever had a manual hub option anyhow...??

 

Oh yea ...I know for a fact some 3rd Gen 4Runners had them as my x gf had them on her 97 Limited 4rRunner.She hated them as she had to get out to lock them.lol
3RD Gen 4runners are a direct swap