Originally Posted by wranglerWestLA
How difficult is to drop the fuel tank?
What are the steps?
What are the risks?
I've done it exactly one time. It isn't difficult if you follow procedure (I had a more knowledgeable friend help).
Here are simplified instructions cut/pasted from wikianswers:
"Well, on the TJ model, the first thing is to take off the gas cap, then push down on the little valve inside the gas filler neck to release any pressure in the tank. Then go under the hood, and unplug the relay for the fuel pump. This is in the small fuse block on the battery side of the car, and is marked as fuel pump relay.
Next, go back and unscrew the four phillips head screws that hold the filler neck to the filler hose. (Be very careful not to drop them into the filler neck when you get them loose.) Now, under the car, on the drivers side, above the fuel tank you will see one electrical connector, and two hose connections. The electrical connector has a small red plastic clip that you have to slide to the side so you can squeeze the black plastic button down and disconnect the two parts. The gas tank side of this clip is attached to the skid plate, so you can leave it there, the gas tank and skid plate come out as a unit. The small rubber hose just has to be pulled off. And the plastic fitting for the other hose has two buttons, one on each side to squeeze to get the fitting to release. This is where you MUST have released the pressure in the tank, or you will have gas all over the place.
Now that the fittings are loose, you can drop the tank. There are seven 1/2" nuts, three on the front of the gas tank skid plate, and four on the back (toward the bumper). Note, there are rubber covers on two bolts on the back of the tank. these bolts stay attached, so leave them alone.
Use a floor jack or such to put a little pressure on the bottom of the skid plate, then undo the seven bolts discussed above. Now, slowly drop the tank down, guiding the filler hose out from the fuel door, and under the Jeep. If all is done right so far, you have the skid plate and gas tank assembly sitting on the floor.
Slide the tank out from under the car, and see the large white fitting on the top of the tank. Using a large, dull, flat screwdriver and a hammer, tap one of the raised ridges in a counter-clockwise direction to unscrew this fitting. Once the white plastic ring is unscrewed, the fuel pump, fuel filter, and GAS GAGE will come out of the tank in one unit. Replace or Repair as needed and reinstall in reverse order.
Remember - It is easier to do this with an empty tank
You may have to jack the car up to get clearance to get the tank out
Be VERY careful with the white plastic hose fittings on the top of the tank
When you are done..... reinstall the fuel pump relay"
Hope this helps.