2601 Sisson St
Baltimore, MD 21211
Their Use and Applications
Friction materials as a whole have changed as much as horse power and torque ratings have changed in the past few years. Listed below is a short informational guide to friction material. Each engine, driver, and driving condition is unique. D&W can customize clutches by plate load, torque capacity, and application to optimize your clutch service. D&W has solved problems for U.P.S., local BFI, and Waste Management locations by switching them to a kevlar and ceramic button combination unit, which U.P.S. now demands at the OE level. We can help you too.
The kevlar/aramid fiber material that D&W utilizes is developed and manufactured in the U.S.. When used in the proper applications, it can outlast other friction materials two to five times. Kevlar provides the pulling capabilities of ceramic button materials along with the smooth engagement properties of an organic facing. By its nature, Kevlar allows for smooth clutch engagement which allows for prolonged life of universal joints, differential gears, and other drive line components.The major cost benefit savings of kevlar, aside from less downtime, is that all of the friction wear surfaces will show little or no wear compared to clutches using other friction materials. A truck originally equipped with a kevlar clutch, and kevlar replacement units, may never need the flywheel replaced!
Ceramic button-style clutch facings are very durable and have the unique ability to grab better as it heats. Organic facings tend to fade as they heat. A ceramic button clutch is appropriate for hard-working applications and has traditionally held up to expectations. However, there are downsides to ceramic material. First, this clutch is either in or it’s out; there is no soft engagement. Second, it is as hard as the material that it mates against, which means that the pressure plate, center plate, and flywheel wear at the same rate as the ceramic facing. This high rate of wear often means that the flywheel will wear out well before the engine or truck does. Therefore, there is an additional expense associated with using a ceramic button clutch. For those customers who work their trucks the hardest and carry the heaviest loads, the ceramic friction clutch is still the best choice because it handles the heat better than any other friction material. D&W offers ceramic buttons made by SK Wellman and Miba, OE suppliers, which are made in western Europe. Ceramic button clutches are the preferred and recommended choice for dump trucks, refuse vehicles, off-road equipment, and heavy hauling in mountainous terrain such as logging and coal hauling.
Fibertuff is a product designed to give the wear of a ceramic facing, yet have the engagement and disengagement qualities of an organic material. Fibertuff is a product of Canada and is intended to wear against its mating surfaces like organic material. Used primarily in the stamped steel and 14”cast units, this product offers greater life than organic material with many of the same qualities that organic friction has traditionally offered. Around-town delivery trucks and mid-range applications find that this product works best.
Carbotic, recently introduced by the manufacturer of Fibertuff, was designed to offer super smooth engagement, like both the organic and kevlar materials. In addition to smooth engagement, this product has excellent service longevity and the ability to handle high horse power and high torque requirements like the ceramic button, but without the harsh wear of the mating surfaces. This product is best utilized in heavy hauling vehicles such as quarry dump trucks which encounter steep grades where clutch slippage and high heat generation are probable. We have also used it in tractor pulls and truck racing vehicles.
The basic organic disc has been in the industry for 50 plus years and has evolved considerably due to engine alterations as well as environmental issues. Organic facings were originally made with asbestos, but as health issues arose concerning the use of asbestos, it was phased out of the industry. Facings were then made of fiberglass and brass as its main ingredients. Varying ingredients by different manufacturers have caused brand loyalties to exist among rebuilders. D&W primarily uses FMC facings from the U.S. who also supplies Eaton Corp. An organic facing should be used in engines with low to medium horse power and torque where the clutch must be engaged and disengaged many times a day. This type of clutch is one of the smoothest engaging clutches in the industry today. Its downside is its short life span.
Kevlar® is a registered trademark of E.I. du Pont de Nemours and Company