What is this leaking?

[Gutterdoc503]

Hello all. I have a 1998 Ford Explorer 5.0 AWD. I have noticed the last several months that my wheels are grabbing and there is a popping when I make turns going at a slow or idle speed. I have changed the fluid in the rear axle with the recommended fluid from the owners manual. The fluid was black and seemed to have a rough smell to it. After I changed the fluid, It seemed to be better. Fast forward a week and now it is back again. There is a noticeable decrease in gas mileage, especially in the city. I crawled under it to day to see if I could find anything else as the rear end was covered in fluid. There is another pan (looks to be) just in front of the rear axle that was also covered in fluid. Both were extremely hot to touch. I could only hold my hand on them for a few seconds. In front of the pan, there is a shiny metal part that connects the pan to the rear drive shaft. I noticed a drop of fluid there. Does anyone know what this part is called? I tried to upload a pic but I can't figure out how to on my phone. Thank you all in advance for your help.

 

[1998Exp]

A photo would help, but sounds like the 'pan' that you are talking about is the transfer case (the transfer case is what makes your truck AWD, by driving both the front and the rear axle). It's probably leaking, and overheating for lack of fluid - or perhaps it started leaking because of the severe overheat. Do all four tires on your truck match? If not, that's a good way to destroy the transfer case.
The rear differential may be bad too, If it's limited slip (axle code D4), it may have have bad clutches, which would explain the grabbing and popping on turns. At this point you should probably take the vehicle to a drive train shop for evaluation.

 

[Gutterdoc503]

How do I add a picture from my phone? I took one of the leaking part but can't figure out how to add it. Or do I need to upload it to my computer and add it from there?

So does transmission fluid go into the transfer case? I can add fluid and see if that helps. Always try the cheap stuff first. Lol. As soon as you walk into a transmission shop around here it's two grand for whatever the problem is.

 

[Gutterdoc503]

Oh, and yes, all four tires are the same size. Several months ago I had one going low and didn't realize it until it was almost flat. Had to drive to the gas station to get air. Maybe that has something to do with it? Since then I have made sure that they are all within at least 2 PSI of the same pressure. I try to keep them all the same but apparently one of the tires likes to expand and contract with weather more than the other two.

 

[Mbrooks420]

There's no 'pan' on the transfer case. The first pan in front of the rear axle is the transmission. It's possible this is leaking (or a cooler line is) and it's transferring to the rear axle when you drive. If the rear axle is leaking, it's likely a pinion seal. Fairly common issue. It's normal for diff fluid to be stank.

 

[J_C]

How do I add a picture from my phone? I took one of the leaking part but can't figure out how to add it. Or do I need to upload it to my computer and add it from there?

So does transmission fluid go into the transfer case? I can add fluid and see if that helps. Always try the cheap stuff first. Lol. As soon as you walk into a transmission shop around here it's two grand for whatever the problem is.

Some ATF fluids seem safe to use in the TC, but Motorcraft stopped making Mercon and now specs Mercon V for tranny but right on the bottle it states not for transfer cases. For that some have used other brands of ATF or Motorcraft makes an XL-12 TC fluid.

You can put the imgur app on your phone to upload it to them, then copy/paste the link on their site into the forum post box by clicking the "image" icon above it.
http://imgur.com/apps