Faults:

Ball joints wear out (every 60,000 miles). This is due to them being "maintenance free". They cannot be greased. Therefore, you have to replace them about ever 50k - 60k miles. Plus, to make things worse, the upper ball joints are part of the upper control arms so you have to replace the entire assembly. About $200-400 per occurrence.

Radio display quit working. This is due to the worst designed heating system I have ever seen. Heating system you ask? Yes, that's the real problem here. The heating vents are directly over the radio. Because of this, and the fact that the dash board does not "breath", the radio is subjected to large temperature swings. Eventually, a few resistors/capacitors on the radio's power board will break loose. It will still work, but without the display. You can fix/replace the radio, but it will happen again.

Need to slam on the brakes to get the heater to work. Again, this sounds really strange, but can be explained... You see, there is a plastic arm that controls the blend door (it controls hot vs cold). It tends to break which may leave the blend door to swing on its own. I have found out that if you slam on the brakes, you can get the blend door to move to a position that will allow hot air to come through. As long as you keep the heater fan on, it will stay in that position. Luckily, though, Max A/C can overpower this so I am left with either full heat or full A/C. Unfortunately, its about a $1200 fix because only the dealer will do it (due to air bags) and they have to remove the entire dash board. The newer Explorers use a more durable material for this arm.

Transfer case needed rebuilt (twice). Apparently, there are a few plastic parts in the transfer case (a pretty stupid idea if you ask me). I have managed to melt these parts twice so far. Each time has left the Explorer with only 4WD low. First time was about a $1600 fix. Second time was under warranty from the first time as it happened only 6 months later.

Transmission needed rebuilt. The transmission died about 2 days after the transfer case (above). I believe it was because of it. Another $2200 fix.

I have had many other (minor) problems that are to be expected of any vehicle. What I have listed above are what I consider major design issues. If you have a 1998 Explorer, you should expect similar problems. I have talked with others that have this vehicle and they seem to all have some of these things in common--especially the radio.

General Comments:

Other than the design issues that I listed, I really think this vehicle is all right. It is comfortable and quite powerful and is very nice to drive through the mountains. I have had it on a few true 4x4 trails and it does okay. It has low ground clearance which limits it quite a bit.

I have kept it for about 130,000 miles so it really isn't that bad. I would say that I spent about $5000 total on repairs that should not be necessary. Most of that was when the transfer case/transmission died. Still, I don't think I would buy another one. Just too many stupid design flaws.

Faults:

Front end was making strange noises at the time of purchase. The dealer had this fixed, but a few months after the warranty ran out, the noise came back.

The turn signal switch had to be replaced.

Various problems with the electrical system over the past two years.

The radio caught fire and needed replaced.

The four wheel drive system makes awful noises when turning and I am scared to use it.

General Comments:

I like the looks of the car. The inside is very nice and it used to drive like a dream. There are just too many problems with the vehicle.