The Jeep Wrangler is a real workhorse. Since their origin in World War II, Jeeps have been designed to be rugged, dependable transportation. However, as in all vehicles, clutch parts wear out, become sloppy and eventually fail. Understanding the parts involved, and how the clutch works in your 2004 Jeep Wrangler, will help you diagnose problems and learn how to correct them.
Flywheel
The flywheel is a large, solid steel wheel mounted to the Wrangler's crankshaft. The outer surface is machined flat so the clutch plate can form good contact with it. However, dirty road water can splash up onto this surface. Over time these oils and contaminants bake on and form a glaze that interferes with clutch performance. A common symptom of this is a slipping clutch, with a burning smell coming from the bell housing area. The glaze can be removed with a honing stone, restoring the ability of the clutch plate to achieve a solid "bite" against the contact surface.
Clutch Plate
The clutch plate is the heart of the clutch assembly. It is the component that makes contact with the flywheel and pressure plate. The clutch plate has two surfaces made of material similar to that in a brake pad. Over time this material wears off, and the clutch plate must be replaced. This is a very common problem. These plates are inexpensive and readily available at many auto parts stores. If your clutch feels as if it's slipping, this is the first place to look.
Pressure Plate
This plate lies on the other side of the clutch plate. When you depress the clutch, the throwout bearing acts on this plate and releases pressure from the clutch plate. It has a flat machined surface that, like the smooth flywheel surface, can become glazed over. Two common symptoms of this are a slipping clutch along with a burning smell, and the clutch pedal will have a spongy feel. A honing stone should be used to remove the glaze, allowing the clutch plate to have a good "bite" again on the pressure plate.
Throwout Bearing
When you depress the clutch, a fork-like lever pushes a sealed ball bearing into the pressure plate, releasing pressure. Like all bearings, these eventually wear out. If you hear a rumbling noise every time you depress the clutch, the first suspect should be the throwout bearing. Also, if there is a burning metal smell, the bearing could be seized. The throwout bearing is also readily available in many auto parts stores and is fairly inexpensive.
