97 major front end problems please help!!

Hello everyone, sorry to bother I am not at all famiar with jeeps, but I am really trying to help out my mother. She has a 97 grand cherokee with the 5.2 and full time all wheel drive (I am not even sure if that is standard or not). It has about 80,000 miles. Everything seemed to be fine when she baught it a few months ago. TWO WEEKS AGO the seal on the front differential, where the driveshaft hooks to, got torn apart and blew that heavyweight oil everywhere under the car on the interstate. She said that she knew to pull over when smoke was pouring out from behind her car.... (because of the oil on the exhaust). Since then she had that seal replaced. NOW the front end is making a loud humming when she is on the interstate(Im guessing the differentail gears and axels were dammaged due to a lack of lubrication), and for some reason the truck is pulling to the right real hard, which it never did in the past. One thing I can add from driving this beast... When she first got it, it seemed to turn a lot easier than it does now, even before this seal broke. Recently, it seems like it doesn't want to turn. When trying to pull into a parking spot...or even into the driveway, the truck slows down substantially, forcing you to give it gass to keep it rolling and it jumps around on the front wheels, like it wants to go foward instead of turn with the tires screaching all the time. We blamed this annoyance on the full time four wheel drive, as neither of us are familiar with it. I really dont know if these things are supposed to be that hard to turn. When I looked at the front end with the wheels turned all the way in one direction.... it seemd that one weel is turing farther than the other.....by what I know this sounds ridiculus, but is it possible. Could the stearing and differential problems be seperate? or related?

Sorry the story is so long. If anybody can give any advise, where to look, what to start changing, difficulty levels, prices, parts lists... absolutely anything...to get thie front end solid again and the truck turning correctly, I would be greatly appreciative. Sorry to sound like I am begging for answers, but we are getting desperate with this. Prices, towing, and mechanic bills are adding up. I really need to know what I am getting in to in order to get her a reliable car to drive.

thank you in advance
Andy

Okay, now I'm being told that the mechanic said that he seemed to think this noise is comming from the bearings. If it happens to be the right hub or axel bearing that is shot, this would make sense to me. (it is dragging to the right) I have never delt with anysort of four wheel drive before, so what would I be getting into if I tried to change these bearings myself. Are there any sort of diagrams/instrucitons/special tools I should be aware of just short of buying a haynes repair manual.

Okay, now I'm being told that the mechanic said that he seemed to think this noise is comming from the bearings. If it happens to be the right hub or axel bearing that is shot, this would make sense to me. (it is dragging to the right) I have never delt with anysort of four wheel drive before, so what would I be getting into if I tried to change these bearings myself. Are there any sort of diagrams/instrucitons/special tools I should be aware of just short of buying a haynes repair manual.

The hummering noise is deffinately BEARING NOISE you are hearing. Although it is prabably not Wheel bearin/hub bearing you are hearing but it is the Differential side bearing (Carrier Bearings) and Front and rear pinion bearings inthe front axle. But you could check the wheel bearings, jack the front of the jeep up (both wheels are off the ground) grab ahold of the top and bottom of the wheel rock the wheel back and forth if the Wheel/Hub Bearings are bad you will feel the play in the wheels. If no play is noticed then the problem is most liekly on the inside of the axle (differential and pinion bearings), which would make sense....

The repalcement of the wheel bearings/hub assemblies are very simple. No real special tools needed, the only one tool you may not have is a 1-7/16" socket for the axle nut. Try to search for wheel bearing removal on here, I posted instructions awhile back about how to replace the hub assemblies. Or you could email me and I will give you the instructions along with some pics.

Make sure you have a 13mm 12-point wrench as well.