How does 93 4x4 work?

[93junker]

I was wondering if someone out there had an understanding of how the 4wd system works in a 93 explorer 4x4 with auto hubs. I understand the push button on the dash, the computer in the back, and the 4x4 shift motor. How does it work beyond that? once the transfer case begins to turn what happens? How do the shafts that connect to the front tires work? Am I right that the shaft going to the passenger wheel is a 2 piece shaft? How does it engage the hub assmebly on the passenger side? When I engage 4wd the two piece shaft spins freely (not together as if they are connected, basically the t-case side shaft spins and the wheel side shaft does not). It looks as though the shaft coming from the hub side, slides into the shaft coming from the t-case side. Is this right? It's kind of hard to see due to the rubber boot covering the connection. Does anyone know how the system works when working properly. Oh you might of guessed, my 4wd does not work. But t-case does engage and turn! This may be helpful too, when engaging 4wd I can hear a slight click coming from the drivers side thus assuming that side is engaging but nothing from passenger side. I'm thinking the problem is with the 2 piece shaft that powers the front passenger side wheel. Any help is much appreciated!!

 

[410Fortune]

the auto hubs engage once the axle shafts apply force (start turning)

The transfer case has a chain that connects the front driveshaft to the out put of the transmission. Once the front driveshaft turns the axle shafts turn inside the spindle and hub, the auto hubs pick this up and go into locked position.

Manual hubs are stronger and more relaible. the OEM auto hubs are good but over time wear out and will fail.

Now your front differential is open, which means power may only be sent to one wheel at a time (this is why when you lift a front tire, the tire in the air spins. the power follows the path of least resistance)

What makes you think your 4x4 is not working?
If the T case is working, you have confirmed it locks the front D shaft in Hi and low range then it is likely a hub is bad. that is if something is wrong.
4x4 doees not = all 4 wheels turn.
it requires a traction control device or locker in the differentials in order to get true 4wd.

 

[DeRocha]

welcome to the site.. you'll find lots of info by using the search button and also be reading the "Sticky" threads in each forum.. The biggest 4x4 failure is with the autohubs themselves.. The transfer case powers the front drive shaft which enters the front differential. From the diff power is sent to the passenger and driver's axle shafts. As these shafts spin they cause the auto hubs to lock onto the axle shafts (basically connecting the wheel to the shaft).. Autohubs can fail from simply being packed with grease.. the hubs should only be coated with a thin film of grease as anything more can/will cause the autohum to hydro- lock towards the disenged position thus preventing the axle from being connected to the wheel... Check out the repair info in my sig for info on the 4x4 system and on cleaning the hubs.

 

[93junker]

I don't believe 4wd is working due to a post on this site. I read that a true test to see if 4x4 is working is to jack the truck up and put it on stands (all 4 tires) and engage 4wd. When I did this I could physically see the t-case turning and the shaft leading to the passenger side was spinning but only one of the 2 shafts, since I belive it is a two piece shaft. The second shaft was kind of just bouncing around not spinning or anything. I also manually turned the tires once off the ground to lock in the auto hubs. One last observation, the front tires never turned when engine was accelerated. Thus leading me to belive that the connection for the two piece shaft is broken and losing all power at this point because it is free spinning and under no load. does this seem possible??
also, last snow we had 4x4 did nothing for me

 

[DeRocha]

ouch... Let me get this straight.. The passenger side axle shaft comming from the diff is rotating, but the stub axle shaft connected to it (at the rubber boot) is not? You are correct the 2 piece passenger side axle shafts are connected via a splined slip joint and will rotate together.. It sounds like the stub axle shaft coming from the wheel has broken off inside the slip joint.. Best case scenario, the break is clean and you just need a new stub axle and U-joint. Worst case is the skip joint is fubared which will required you to remove the front drive shaft, separate the front diff from the TTB so you can remove the "C" clip securing the slip joint axle shaft. The axle seals should also be replaces as the flopping around of the shaft will have compromised the seal and cause a fluid leak. To verify you could remove the metal bands securing the rubber boot and slide it back exposing the joint.

 

[93junker]

thanks for the info. I'll have to get down there and tear it apart when I get time and motivation. Hopefully the whole thing is not fubared and it will not be too bad of a fix. Ill let ya know how it goes.

 

[93junker]

Hi everyone. Well I still haven't gotten around to tearing the front end apart yet. Although, the weather is getting nicer out now, so I'm thinking I might give it a try here pretty soon. Referring to replacing the passenger side axle shaft for 93 auto hub 4x4. While I have things apart I was also thinking about replacing both upper and lower ball joints. Driver and passenger sides. Is there a known link that details removal/installation for a 93 explorer with auto locking hubs?? I've tried searching and all I came up with was details for a 97 2wd. I'm thinking the process will be pretty different for mine. Also are there any other parts I should look into replacing while the explorer is sitting in pieces? I was also thinking about doing the tie rod ends at this time too. Oh also, one last thing. Is there any new information on the shimmy/unbearable shaking around 65mph???? Any and all info I've seen on the site so far says it's a mystery?? Everytime I drive on an expressway I just want to drive it off a bridge or into a tree, anything to stop the SHAKING!

 

[DeRocha]

All the info you seek can be found with the search feature... Check out Glacier's 1st Gen Brake Diary for lots of good info and pics on removing the front brakes, bearings, rotors etc..