There is a wire that is hanging from the bottom of my 2001 Jeep Grand Cherokee. Looks like it is attached to the front axle, I think transmission cylinder. It looks like it came loose. I can't figure out where it goes. It's not leaking or anything. So I just have it tied\r\nin place for now.

it may go to the modulator valve on the drivers side of the transmission,if so,,,jack the truck up,use jack stands,,reach up to the hose and connect it to a round shaped cylinder on the drivers side transmission. hard to explain but look at the transmission from underside,towards the front of transmission see a round cylinder with a vacum line missing,thats where the hose will go.then it will shift properly. thank you for choosing fixya.com

1. Disconnect and isolate negative battery cable.
2. Raise and support vehicle.
3. Note: If equipped with 4WD and certain transmissions, a support bracket is used between front axle and side of transmission. Remove 2 support bracket bolts at transmission. Pry support bracket slightly to gain access to lower starter mounting bolt.
4. Remove two mounting bolts (2).
5. Move starter motor towards front of vehicle far enough for nose of starter pinion housing to clear housing. Always support starter motor (1) during this process, do not let starter motor hang from wire harness.
6. Tilt nose downwards and lower starter motor far enough to access and remove nut that secures battery positive cable wire harness connector eyelet to solenoid battery terminal stud. Do not let starter motor hang from wire harness.
7. Remove battery positive cable wire harness connector eyelet from solenoid battery terminal stud.
8. Disconnect battery positive cable wire harness connector from solenoid terminal connector receptacle.
9. Remove starter motor.

If its about 1/4" inside diameter and a soft hose that attaches to the differential or axle tube, it's the vent for the diff. It is usually tucked up against the firewall near the master cylinder and is supposed to have a small vent cap (small but open shield) on it. Just tuck it back up there and secure it with a tie wrap so it doesn't drag and it will be fine.

it looks like your hub seals are leaking you will have to strip down and fit new seals

First thing to test is to see if the front driveshaft is getting engaged from the transfer case. With the vehicle in 4x4, and engine shut off, and in park, crawl under and try to turn the front driveshaft by hand. The driveshaft looks like a pipe that runs from the transfer case, located just behind the engine/transmission, to the front differential. If it rotates by hand, there is a problem with the transfer case. Some Jeeps have a vacuum actuator on the front diff that slides a collar inside the axle tube to engage it. I will watch for you findings, and you can leave me another message, and I will be happy to chat back with you on your findings.

That may be the fuel return line thats why it is using to much fuel. Do you notice fuel odor under your vehicle?

The starter is on the right side of the engine, at the same place the transmission is located. Remove the neg. battery cable first, on 4WD models remove the front axle skid plate ( if equipped with), then disconnect the wires from the starter, disconnect any clips that hold the wiring in position, remove the mounting bolts from transmission side. It may be easier to disconnect the wiring after the starter is removed from the engine. Make sure to keep the starter supported and do not allow to hang by the wiring.

Check vacaumn line attached to front axle and connect or replace if damaged

If there is no obvious place to attach this hose, and it doesn't appear to be broken at the end from being attached to something, it's probably a vent tube from the axle, and is nothing to worry about.

If both vehicles are Grand Cherokee's a lot of the components will fit. Some of them are not worth putting used items on because they may already be worn out. The mounting of control arms are virtually the same. The front axle on the 2wd looks like a gutted out 4wd axle. The most common issues with that suspension is the "Trac Bar" and "Steering Stabilizer". Those usually last 60k to 90k unless you take it off-road then 30k. The trac bar is the bar that hooks from the housing over to the frame, side to side. The stabilizer looks like a shock attached to the steering linkage.
Good luck, I hope this was helpful?