91 explorer with wierd 4x4 issue

[bad.shimmy]

so my 4x4 wasnt working.... so i pulled of the hubs and cleaned the hell outta them...showroom fresh....reinstalled and went for a drive still no 4x4. the dash light for the button works and i can hear the click of the 4x4 computer in the back.

so i went outside and with the truck on the ground i turned the front drive shaft (tcase to front diff shaft) and noticed the halfshafts running to the front wheels on both sides didnt turn. so i went and tried to turn the halfshafts and both were locked and wouldnt turn in either direction. im kinda at a loss here i expected the front halfshafts to try and turn when i turned the front driveshaft as per the great article on here about testing the front hubs....

no idea where to go from here.....im guessing either the hubs are screwed as the wont turn either direction or somethings wrong in the diff...

either way im new to 4x4 and would appreciate any ideas or suggestions anyone has

thanks again all
j

 

[MrShorty]

If you can turn the front driveshaft without turning at least one of the axleshafts, something is broken inside the front differential.

If the transfer case is in 4H (or 4L), and you can turn the front driveshaft without turning the rear driveshaft, something is broken inside the transfer case.

 

[bad.shimmy]

crap that's what i thought....so the hubs not turning doesnt matter if the front diff is blown?
thanks for the info bud

 

[MrShorty]

.so the hubs not turning doesnt matter if the front diff is blown?

The way you described it, I would guess that the hubs are locking just fine. If you want to test the hubs, jack up a wheel and see if you can rotate the axleshaft without turning the wheel (If you have manual hubs, you'll need to test in both lock and free position). If you can turn the axleshaft without turning the wheel (auto hub or manual in lock), then something is wrong with the hub.

 

[bad.shimmy]

Yep tested the hubs they are good...anything special I'm looking for inside the diff? When I pop the cover. Haven't done much with them aside from just changing the fluid...

Thanks for your help shorty mucho appreciated

 

[MrShorty]

anything special I'm looking for inside the diff?

Usually with this sort of thing, the failure would be fairly "catastrophic" -- something (a gear a shaft or something) is broken. You'll be looking for pieces of a gear to figure out what part or parts have failed.

 

[bad.shimmy]

it looks like it's gonna be a pain in the ass to get to any tips?

the front driveshaft coming loose and getting the pumpkin off wont be the end of the world....if i need to take the halfshafts loose any tips there?

thanks again all