The network of drive belts installed on the engine block of the Jeep are the vehicle's link to a slew of mechanical auto parts scattered throughout the system. These parts typically depend on the engine for power, and the Jeep drive belt is the designated power transmission medium of the engine block to supply the necessary engine assist to these auto parts. From the power steering pump to AC compressor and air intake system, among others, these Jeep parts are individually fitted with different kinds of drive belts, depending on their applications. A Jeep drive belt usually links an auto part through a gear set. Made of reinforced and tensile synthetic rubbers, the Jeep drive belts interchange rotary and linear motions to transmit power. They sport a toothed finish and their design comes in two variations: the traditional V-belt and the now-standard serpentine belt. The Jeep V-belt has a V-shaped cross-section, as opposed to the multiple V-shaped teeth of the Jeep serpentine belt. Because drive belts are structurally designed to pull gears, the serpentine Jeep drive belts, also called PolyV, Poly Rib, Multi Rib, and MicroV belts, are used in order that precision is ensured. The transverse groove design of the Jeep multi rib belts enables the rubber to run the pulley at a cooler temperature. In the face of heat when the rubber engages the gears, the Jeep multi rib belt reduces rib cracking, thereby increasing the life of the belt by at least 40 percent. The grooved design provides flexural stress relief, which allows for increased flexibility in both normal and backside bending. The grooves also render the Jeep multi rib belt less susceptible to environmental factors such as dust and splash-induced slippage. Due the nature of its job, however, no Jeep multi rib belts outlast other maintenance items on the vehicle. Jeep drive belts ordinarily have a 100,000-mile service. Beyond that time frame the rubber finish of the Jeep multi rib belt tends to glaze on the gear which, if left unchecked, can make the belt hard and brittle.