4wd issues (auto hubs)

[shadowless127]

Last night I took the 93 X out for the first time since wednesday. It's snowed twice since then so I figured it was time to take it out. It has an issue where if you don't use 4WD for an extended period of time you have to push the button for 4hi a bunch of times before it engages (once u engage and disengage it 2 or 3 times it turns on the first time u press the button). So I got it engaged and headed out the driveway. I get on the road and it starts pulling HARD to the right and there's a very noticable whine/hum coming from the front (drivers side sounds like) as i'm accelerating. I got home after driving around the neighborhood with it (about a mile, of straight and hilly road), pulled in the driveway, disengaged 4wd and pulled back out. Still got the hum and was still pulling, not as hard though. I pulled into the fire house parking lot about 1000ft from my house (it was still covered in snow) engaged 4wd and did some driving that the truck would've slipped on otherwise; it gripped like a champ (even with the awful bald tires). Took it out of 4wd and was still humming and pulling....

Could something be frozen near or inside one of the hubs?

Tools, time, and mechanical skills are limited....

And also, is it normal for acceleration to suck when in 4wd?

 

[fixxxer]

Read the 4x4 troubleshooting sticky at the top of this forum

 

[shadowless127]

Reading and searching hasn't answered all my questions, but I think my original assumption that one of the hubs is only partially locking seems to be the way it's going. I'm going to take it out again tonight and see how it does in 2wd, 4hi and maybe i'll get ballsy and try 4lo.

If it is in fact the auto hubs I guess this summer I will be fixing them... hopefully by then we'll have another X.

 

[DeRocha]

When you disengaged 4x4 did the hubs completely unlock? It sounds like one isn't..

Test for a locked Auto hub
1) Jack up the Left (driver's side) front tire and try and rotate the whole wheel (Counter clockwise).
2) If the wheel doesn't move it indicates the autohub is still LOCKED; If so rotate the wheel clockwise to try and Unlock the hub.
3) Jack up the Right (passenger side) and try and rotate the whole wheel (Clockwise).
4) If the wheel doesn't move it indicates the autohub is still LOCKED; If so rotate the wheel counter clockwise to try and Unlock the hub.

 

[troy11556]

sounds like the hub is not disengaged. but if doing the above does not correct the problem then i would reccomend removing the hubs and cleaning and repacking the bearing. because it could also be a bad bearing on that side. if it is i would reccomend swapping for the manual hubs. cheaper and stronger than the auto hubs cost to replace.

 

[shadowless127]

Took it out tonight and was able to find a nice snowy area to do some 4wd testing. 4hi now engages when I push the button the first time; i'm guessing the shift motor just gets a bit stubborn if not used for a while. Took it in the snow and she handled like a dream (Makes me dislike the AWD system in the Mounty). Got back on dry pavement, turned 4wd off. The auto hubs didnt disengage, so i did the Reverse trick. Drove backwards about 15ft, put it in drive and was good to go.

The only issue is while in 4wd she seems to pull heavy to the right... I'm assuming one of the hubs is all gunked up; am I correct on this assumption?

Thanks again for the help; I love this forum

 

[Willard]

Yea, sounds like one of the hubs could be a little gunked up, or something is dragging on one side of the axle in 4wd (bad spindle bearing, axle shaft u-joint...). Try and clean the hubs good first, and then see what happens.

I often have to drive in reverse to disengage my hubs properly, and they are very easy to engage/disengage. Mine however usually also will disengage if I take a sharp enough turn.

 

[troy11556]

by design of the hubs in the gen 1 explorers you need to drive in reverse for a short distance i can normally disengage them in about 3 feet in reverse. when i had a simular problem i removed the hub cleaned and repacked them. and no problem since.... but since i am now running warn manual... which i like i enjoy the 2 low. LOL next project when i get the money is fron and rear lockers.

 

[DeRocha]

As mentioned by Troy autohubs are activated/deactivated by the rotational movement of the axle shaft within the hub. If the axle is no longer being powered (4x4 off) then reversing direction for several feet will unlock them. From the 4x4 troubleshooting guide.

More on Automatic HUB engagement:
When you engage 4x4 the front drive shaft will spin and send power to the diff and then to the axle shafts.. The axle shafts will begin rotating within each autohub; after a few revolutions the engagement cam will have idle up within the autohub and caused the autohub to lock. Once this occurs on both hubs the wheel with the least traction will get power and begin to rotate.

:scratch: Let the above sink in for a minute.. If you try to free a vehicle by quickly going from Forward to reverse you can easily blow an auto hub.. When you reverse direction the axle shaft obviously spins in the opposite direction causing the auto hub to UNLOCK and then LOCK in the new direction.. Under low power this isn't a big deal, but if you're on the gas heavy it can definitely damage the hub... Manual hubs are either locked or open, as such they are unaffected by rocking a vehicle in the manor above.