It was 100 years ago when the local blacksmith realized he couldnt continue shoeing horses in the coming age of spark plugs and gasoline. With a few "minor" marketing adjustments, we’ve evolved into todays aftermarket distribution and service business.
Although changes in todays technology have become less abrupt, many jobbers continue selling various product lines within the paradigms of the past, as if the wheels of progress had indeed ground to a halt. But in order to succeed, or simply stay afloat, in the aftermarket, parts stores must learn to ebb and flow with the changes in technology and distribution.
Belts and hoses are a good example. Sure, accessory drive belts have changed from the conventional "V" configuration to the now traditional "flat" or serpentine configuration. Timing belts, although they serve a different function, follow along the same configuration. And modern hoses? Well, theyre like comparing Grandmas button-ups with your latter-day running shoes. Same parts, but theyre rendered in an entirely different design that is much more application specific.
THE TIMING BELT MARKET
Revolution often approaches through the back door. In the late 1960s, for example, Pontiac introduced the first "rubber" timing belt on their high-performance six-cylinder engines. Most of us in the business took the idea with a grain of salt, dismissing the timing belt as one of those flash-in-the pan ideas that would come and go, as did the highly touted electronic ignitions a few years before.
But, (and thats historys biggest three-letter word) the idea of a flat belt with cogs driving accessories with high-torque demands began to catch on. Drag racers had used cogged belts to drive their superchargers for years. And the six-cylinder Pontiacs chugged on into history without the precipitous failures anticipated by traditionalist detractors.
The introduction of timing belts heralded a revolution in scheduled automotive maintenance. Instead of selling $30 spark plug replacements, progressive young technicians invented a whole new market by putting their finger on "timing belt replacement" when looking at recommended maintenance schedules.
Along with timing belts, these new-age techs began adding water pumps, timing belt tensioners, old-style v-belts, serpentine belts and radiator hoses, not to mention the scheduled spark plug and filter replacements recommended onto the scheduled timing belt replacement interval. Moving the leap from a $30 "point-and-plug" replacement to as much as a $1,200 timing belt service, by the way, isnt such a bad trade-off after all for the parts and service industry.
SERPENTINE BELTS
Todays serpentine belt is a spin-off of the original timing belt design. In the good old days, the conventional v-belt had enough torque-transmitting capacity to turn water pumps and low-output generators. As high-torque accessories like air conditioning, power steering and high-amperage alternators were added, configuring v-belts to transmit needed torque became an engineering nightmare. Most engines ran up to four belts and sometimes more just to drive three or four accessories. Sound complex? Well, really it was, because the belt-tensioning systems on some vehicles became virtual mechanical puzzles for the DIY and professional technician alike.
Unfortunately, increasing accessory loads exposed several deficiencies in the v-belt design. First, only the two sides of the "v" belt generate friction. Second, the thick cross section demanded a relatively large pulley radius in order to prevent fatigue. Last, thick v-belts generated lots of heat because they created lots of rotating friction. High rotating friction also used up valuable gasoline, which became a no-no as time went on.
The serpentine belt, of course, was designed to develop a high coefficient of friction against the pulley without consuming large amounts of horsepower. Serpentines also eliminated the myriad of belt and adjustment configurations that had come to dominate the v-belt market. Because of its thin cross-sectional design, the serpentine belt could operate on smaller diameter pulleys. In addition, the grooved side could drive high-torque accessories while the smooth side of the belt could drive low-torque accessories such as water and air-injection pumps.
In the age of transverse-mounted engines, serpentine belts also offered a compact accessory drive system that added only a couple of inches to overall engine length. The fact that the serpentine belt itself was more cost-effective than a quartet of squealing v-belts proved to be a deciding factor in the serpentine belt dominating todays belt market.
SERPENTINE BELT SERVICE
Of course, nothing in engineering life is without its liabilities. Because of the serpentine belts "flat" design, pulley alignment is critical. The symptoms of poor pulley alignment are shredding along the edges of the belt, belt squeal or rapid wear. Extreme cases of pulley misalignment will throw the belt entirely off the pulleys.
At least one belt manufacturer now offers a laser-beam belt alignment tester that indicates which pulleys are out of alignment. In most cases, misalignment may be due to the incorrect pulley being installed, missing attachment bolts or a broken accessory-mounting bracket.
When dealing with serpentine belt problems on some imports, its always important to make sure that the alternator application is correct. In some instances, more than one type of alternator may be specified for an import, which creates the potential for pulley misalignment.
For maximum serpentine belt life, its also very important to make sure that the pulley grooves are clean and without excessive wear. Occasionally, an old belt will leave large particles of rubber embedded in the pulley grooves, which will cause slippage and noise. In other cases, worn pulley grooves will reduce contact area between the pulley and the belt, which causes belt squeal and wear.
BELT TENSIONERS
A special mention should be made of the importance of inspecting and selling belt-tensioner pulleys. Originally, when serpentine belts were first introduced, they were manually tensioned. Obviously, when the serpentine belt began to wear, it rapidly lost its tension and began to slip on the pulleys, which caused rapid deterioration of the serpentine-belt system.
Although some single-accessory serpentines are still manually tensioned, most serpentine belts use spring-loaded belt tensioners to provide constant, even, tension on the belt to ensure that all of the accessories received full driving torque from the crankshaft pulley.
Tensioners have three basic wear points. The first wear point is obviously the pulley bearing, which can become dry and noisy. The second is the pulley surface itself. Since many flat pulleys are now made from plastic, they tend to develop flat spots or cupping in the belt contact surface, which causes noise and vibration. Last is the belt tensioner pivot, which may wear enough to cause a rattling noise. On rare occasion, tensioners can actually become compacted with road grime and stick in position, which causes the belts to lose tension. Each of these is reason enough to recommend tensioner replacement, especially on high-mileage vehicles that are driven largely at highway speeds.
THE HOSE MARKET
Long-life, precision-molded hoses have become the most important change in todays coolant-hose market. Currently, most original-equipment molded coolant hoses may last well beyond 100,000 miles. The service life of these hoses depends largely upon their exposure to engine oil. When the engine begins to leak oil onto coolant hoses, their service life may be cut in half.
WHEN TO REPLACE HOSES
Because hose replacement on modern vehicles is usually very labor-intensive, the best time to replace hoses is when the engine or cooling system is disassembled for another service such as timing belt replacement. Regardless of mileage, hoses should be replaced when a water pump, heater core or radiator is replaced. Hoses should also be replaced if they appear weathered or cracked, or if they appear swollen or feel spongy around the hose connections. And dont forget hose clamps. New hoses demand new clamps to ensure against coolant leakage.
SELLING TO THE MARKET
Sometimes its the jobbers responsibility to remind their dealers and other installers that replacement parts like timing belts, serpentine belts, belt tensioners and coolant hoses are better sold as a preventive service rather than a repair service. When sold as a preventive service, the installer is keeping the best interests of his customer in mind. When sold as a repair service, the expensive aftermath of broken belts and leaking hoses may often ruin the installer/customer relationship.
