Larry's XJ

The gears would have to be worn extensively to not work at all, and would be obvious. No chipped/broken teeth?

Spin the axle 360* to view all teeth on ring.
No oil is still not good sign.

sycoglitch

What scares me is if the front has no oil, i can imagine how the rest of the parts look, i.e. Rear diff. tC, radiator, oil, tranny. Good chance the front diff is toast but also chance its salvageable with some minor parts

RyanT

When I spin the drivers side front tire, the little gears on the inside (first picture) all spin. But it doesn't cause my other tire to spin. When I spin my passenger side front tire, none of the gears move, as it also doesn't cause the other tire to spin.
When I put it in 4wd, the front driveshaft is spinning, and With the diff cover off I saw every gear in the front diff spinning and doing its thang just as it should be I imagine. But the front wheels are not getting any of that! Why aren't my front wheels gettin in on any of that spinning action LOL I'm gunna start cleaning it out, researching more and keep poking at things. Hopefully I'll be able to figure this out. If any of you mechanically inclined folks have any ideas, feel free to chime in! Thanks!

98XJ40K

No joke... never seen a dry differential before. Can't imagine the PO would have kept maintenance up on everything but that.

Edit: long shot, but could it be that he put on 2wd hubs that just use a stub axle? I can't imagine why someone would do that though.

Edit 2: upon closer inspection of the photo, it appears that there is in fact an axle shaft showing.

Larry's XJ

I'm prepared for flaming, LOL.

My son's axle had ingested water, which turned fluid to yogurt. After cleaning what I could, I installed cover with Permatex #2, filled with diesel, drove around yard forwards & reverse, left&right, drain, repeated untild diesel came out relatively clean.
This axle doesn't have the disconnect axle shaft does it?

It does look rather nasty in there.

RyanT

In coincidence with my last post, I see these inside gears consist of 4 different "cog type gears" that all fit into each other. when the gears are turning while in 4wd drive setting, the top, left, and bottom "cog gears" are all moving, but the right gear (drivers side) is not. But if I spin my drivers side tire while these gears are doing this, that gear on the right moves in cordinance with the speed that I spin the tire. Other than that, the right "cog gear" just sits there as the rest spin circles around it. Is this how the front differential would usually look and act while in action?

GreenManXJ

I would assume the problem is on the side of the second tire you spun that didn't cause anything else to spin (not sure which that is because you said passenger twice). My buddies older wrangler acted the same if I recall when his vacuum disconnect wasn't working. Obviously you don't have one of those unless it's not the stock axle but if you had a broken axle shaft or something I would assume it would do the same. Take a closer look at the side that didn't cause anything else to spin, somewhere you're lacking a connection between that wheel and the diff, should be pretty easy to track down since you can see both ends of the axle shaft, one end inside the diff and the other at the wheel. GL!

94XjSport94

Yes. You're looking at spider and side gears inside the carrier. YouTube how a differential works for a good video explanation, there are a few good ones.

Post pictures of the U joints, hubs, and rear passenger side of the D30.

GreenManXJ

Now I'm really confused. When you spin the drivers side wheel, the corresponding side gear in the diff spins as well? But nothing else?

94XjSport94

That's how an open diff works...

RyanT

Oop greenmanxj, I meant to say while in neutral and I spin my drivers side front tire, all 4 of the cog gears in the middle of the diff will spin. When I spin my passenger side front tire, nothing spins.
But while I'm in 4wd drive, only the passenger side, top and bottom are spinning. But the cog gear on the drivers side (the right gear in my picture) just sits there. If I spin my drivers side front tire, while those 3 gears are spinning, that gear on the right (drivers side) will spin in cordinance to the amount that I spin that driver side tire. Other than that, the gear on the right (drivers side) just sits there as the other 3 gears cog and spin around it smoothly

RyanT

@Larry's XJ Are you recommending putting gas in the diff to clean a real dirty diff? Cuz Ima bout to open the back diff and clean it.
This is the least of my concern for this forum to help me on I can just research that lol I'm mainly interested in figuring out this whole differential situation

GreenManXJ

Ok I think I follow you now. If when in neutral (or 2wd) you spin the passenger side wheel and nothing is spinning in the diff then something is wrong between the wheel and the diff. You should easily be able to see both ends of the axle shaft if you have the diff cover open and it should be a one piece axle shaft. To me it sounds like your passenger side axle shaft is broken. It would make sense too that when in 4wd and on the stands that the two spiders and the left side gear all spin because there is no resistance on the passenger side so that's where all the power is going.

GreenManXJ

Here are images of each end of the axle shaft. On your jeep this should be a one piece axle so if both ends to not spin together I would have to assume it is broken inside the axle unless I'm missing something.

GreenManXJ

The only exception that I can think of would be if for some reason you have a front axle with a vacuum disconnect that would look like this. This is looking at the backside of the passenger end of the axle.