As the ‘80s rolled on, electronics, emission controls and technology were on solid cruise control and like flipping a switch, timing belts were suddenly in the picture. Although timing-belt-driven overhead camshaft engines weren’t new by any means, the value of the design began to be recognized and auto manufacturers started to change over to this concept. The camshaft was now located on the cylinder head, which eliminated push rods and, on some designs, the rocker arms were eliminated as well, saving weight, lowering cost, reducing valvetrain inertia and making multi-valve designs possible. The easiest way to drive the camshaft was via a timing belt. Since timing chains suffered from inherent gear wear and stretching, engineers decided that belts were the way to go. They were quieter and lighter than a chain and less expensive to manufacture. The tensioning systems were simple, and the belts remained tight for a long time without wearing the cam or crank gear. Seemingly, all was good, but even with the advantages of a timing belt, they required replacement at specific intervals, and the one disadvantage that became known quickly was that if not replaced, they would break with no warning. Simple tensioning systems required adjustment from time to time, and oil leaks also were a problem with timing belts, as they would degrade the rubber quickly and lead to a broken belt. A broken belt could mean a very expensive repair on interference engines. Belt quality and tensioner design improved quickly, eliminating many of the early timing belt troubles, and by the mid- to late-‘90s, timing belts were used on the majority of automobile engines. Belt-service intervals became longer, and consumers were getting used to this being a part of normal maintenance. But you still cannot ignore the replacement interval, and was it possible times were changing again? The Old Ball and Chain As we said “Happy New Year” to a whole new century, engine technology was a freight train out of control. Materials and manufacturing were better, RPMs were higher, turbochargers were boosting like never before and horsepower wars like we hadn’t seen since the ‘60s were heating up again. Smaller engines were producing more power than ever, and variable valve timing was pushing engine performance to the limit. Just like that, engine design required something that was narrower, more durable and more dependable than a timing belt, and consumers no longer wanted the associated maintenance. Hello chains. As of the last decade, timing chains have risen back to the top. Design is far different than that of old, with modern chains traveling around awkward paths of sprockets, hydraulic tensioners and chain guides, offering a high level of dependability and performance. But they couldn’t do it without one critical thing on their side: lubricant technology. A primary reason for timing-chain wear always has been related to lack of oil changes, lower-quality oil, and poor or non-existent positive crankcase ventilation (PCV) systems, which wreaks havoc on engine oil. Modern engine oil is not only far superior than it was just a few decades ago, but PCV technology also is eliminating the majority of blow-by-related contaminants and moisture from building up, resulting in cleaner oil and better lubrication throughout the engine. Timing chains and variable valve timing systems are dependent on clean, healthy lubrication and now they have it, but then again, does everyone change oil as often as they should? Talk to the Techs Timing belts generally are easier to service. This is primarily because they’re located on the outside of the engine and run dry, with no lubrication. When replacing a belt, there’s less cleanup and no time required to reseal engine covers. On the other hand, the engine water pump is frequently driven by the timing belt, so when you replace it, it’s a good practice to replace the pump, as well as any tensioners or rollers. Timing belts came into prominence along with the inline four-cylinder engine. What this brought was more than just cam/crank timing, but also balance shafts and intermediate shafts that often drove distributors and oil pumps. These weren’t hard to work with, but had to be timed correctly during belt replacement. As the timing belt migrated to V-configuration engines, it became a lot longer with additional rollers and a more difficult installation, plus some components such as thermostats were all of a sudden underneath. Some things got better, some got worse. Inspection is an advantage with a timing belt; it’s usually just a couple of bolts and you’re looking right at it. One problem, and a challenge especially on a second-owner vehicle: If the mileage is over that of recommended timing-belt replacement and the owner doesn’t know if it was done, replacement is always recommended. Many belts can look great on the outside but strip the teeth off a day later. The only way to inspect them closely enough to really look at the integrity of the teeth can be to remove them. And then, does it make sense to put the old one back on, and is there a technician who would want to take that gamble? One solution to this is the bright yellow replacement decal that’s included in almost every timing-belt kit, for a technician to fill out and affix under the hood. If only they got used more often. Timing chains, as good as they have become, are not without faults. They can be a bear to inspect and replace, mainly because they’re located inside the engine so they can be lubricated by the engine oil. There’s a lot more cleaning to do and usually a seal or two that needs replaced. Just as with belts, there’s often a water pump that’s driven by the chain that should be replaced. While the chains are more durable and dependable, if oil changes aren’t religious, the guides have a tendency to wear out really quickly. Most guides are steel with some type of nylon or plastic that the chain rides along. Remember the nylon-tooth cam gears? These guides do the same thing and beyond a certain point in wear, the tensioner can no longer take up the slack in the chain. This often leads to a rattling noise and a “Check Engine” light. Most engines still run perfectly fine at this point, with the most common complaint a “Check Engine” light and a cam/crank correlation DTC. Timing-chain replacement is often very expensive due to labor time, but, then again, so is engine repair when a timing belt breaks. They both require special tools at times, so there’s no winner on that argument. And, one more thing: Did we mention the latest technology of belt-in-oil drive systems? Here we go again. So, do you have a preference, or do you agree with my conclusion?

The Schaeffler Group considers its goal to minimize the environmental impact of its business activities foundational to its future company success.

Timing chains and variable valve timing systems are dependent on clean, healthy lubrication and now they have it, but then again, does everyone change oil as often as they should?

Frontwheel bearingnoise symptoms

Timing belts came into prominence along with the inline four-cylinder engine. What this brought was more than just cam/crank timing, but also balance shafts and intermediate shafts that often drove distributors and oil pumps. These weren’t hard to work with, but had to be timed correctly during belt replacement. As the timing belt migrated to V-configuration engines, it became a lot longer with additional rollers and a more difficult installation, plus some components such as thermostats were all of a sudden underneath. Some things got better, some got worse. Inspection is an advantage with a timing belt; it’s usually just a couple of bolts and you’re looking right at it. One problem, and a challenge especially on a second-owner vehicle: If the mileage is over that of recommended timing-belt replacement and the owner doesn’t know if it was done, replacement is always recommended. Many belts can look great on the outside but strip the teeth off a day later. The only way to inspect them closely enough to really look at the integrity of the teeth can be to remove them. And then, does it make sense to put the old one back on, and is there a technician who would want to take that gamble? One solution to this is the bright yellow replacement decal that’s included in almost every timing-belt kit, for a technician to fill out and affix under the hood. If only they got used more often. Timing chains, as good as they have become, are not without faults. They can be a bear to inspect and replace, mainly because they’re located inside the engine so they can be lubricated by the engine oil. There’s a lot more cleaning to do and usually a seal or two that needs replaced. Just as with belts, there’s often a water pump that’s driven by the chain that should be replaced. While the chains are more durable and dependable, if oil changes aren’t religious, the guides have a tendency to wear out really quickly. Most guides are steel with some type of nylon or plastic that the chain rides along. Remember the nylon-tooth cam gears? These guides do the same thing and beyond a certain point in wear, the tensioner can no longer take up the slack in the chain. This often leads to a rattling noise and a “Check Engine” light. Most engines still run perfectly fine at this point, with the most common complaint a “Check Engine” light and a cam/crank correlation DTC. Timing-chain replacement is often very expensive due to labor time, but, then again, so is engine repair when a timing belt breaks. They both require special tools at times, so there’s no winner on that argument. And, one more thing: Did we mention the latest technology of belt-in-oil drive systems? Here we go again. So, do you have a preference, or do you agree with my conclusion?

Automatic transmissions are in the majority of all new vehicles; however a manual transmission has some advantages in efficiency and performance.

As the timing belt migrated to V-configuration engines, it became a lot longer with additional rollers and a more difficult installation, plus some components such as thermostats were all of a sudden underneath. Some things got better, some got worse.

Early engine design was split between gears or chains, but chains ultimately became more popular because they took up less space and ran quieter, and by the early ‘80s, the majority of cars produced had timing chains.

Badwheel bearingsound

If you were buying a new vehicle, what would you want the engine to have: a timing belt or a timing chain? You may have an opinion, you may not. Either way, let’s compare the two; then you can decide. Related Articles - Yokohama Tire Becomes a Lifetime UAF Trustee - SKF Offers Free Online Training in North America - NAPA Partners With UAF to Offer $50K in Scholarships The Chain Gang For many years, timing chains were the go-to for engine design. Generally speaking, they were dependable and didn’t require any specific maintenance. They were lubricated by the engine oil, so if you changed it on a regular basis, the timing chain would hold up well. Or would they? A lot of people still say, “They don’t build them like they used to.”  This is true, and coming from someone who is an old-car enthusiast, I’ll defend a level of workmanship that we don’t see in today’s vehicle. But the statement, while true, doesn’t always mean they built them better. In the case of timing chains, they sometimes wore quicker than a lot of people realized. What happened when they did? On an old car, nothing right away. At least nothing of which the owner was aware. A timing chain, just like a belt, is there for one reason: to connect the crankshaft to the camshaft at exact points so the valves open and close at the correct time for engine operation. A traditional, old-school timing chain was tight upon installation, and the overall timing set consisted of a crankshaft gear, a camshaft gear and a chain. There was no adjustment or no tensioner. When the chain or the drive gears began to wear, engine performance would suffer, but it would degrade slowly, and most vehicle owners had no idea there was a problem. They wouldn’t know at all until they started to get a hard-start or no-start symptom. And why? There was no crank sensor or cam sensor, and no computer to translate the signals into a crank/cam correlation diagnostic trouble code (DTC). So, we just drove the cars until they wouldn’t drive any more. Early engine design was split between gears or chains, but chains ultimately became more popular because they took up less space and ran quieter, and by the early ‘80s, the majority of cars produced had timing chains. An evolutionary change of timing-chain design included nylon-tooth cam gears. They ran quieter than a traditional steel gear, but they wore out a lot quicker and created problems long before vehicle owners expected, which didn’t do much for their reputation. The tried-and-true timing chain was simple and generally dependable, but times were changing. Buckle Your Belt As the ‘80s rolled on, electronics, emission controls and technology were on solid cruise control and like flipping a switch, timing belts were suddenly in the picture. Although timing-belt-driven overhead camshaft engines weren’t new by any means, the value of the design began to be recognized and auto manufacturers started to change over to this concept. The camshaft was now located on the cylinder head, which eliminated push rods and, on some designs, the rocker arms were eliminated as well, saving weight, lowering cost, reducing valvetrain inertia and making multi-valve designs possible. The easiest way to drive the camshaft was via a timing belt. Since timing chains suffered from inherent gear wear and stretching, engineers decided that belts were the way to go. They were quieter and lighter than a chain and less expensive to manufacture. The tensioning systems were simple, and the belts remained tight for a long time without wearing the cam or crank gear. Seemingly, all was good, but even with the advantages of a timing belt, they required replacement at specific intervals, and the one disadvantage that became known quickly was that if not replaced, they would break with no warning. Simple tensioning systems required adjustment from time to time, and oil leaks also were a problem with timing belts, as they would degrade the rubber quickly and lead to a broken belt. A broken belt could mean a very expensive repair on interference engines. Belt quality and tensioner design improved quickly, eliminating many of the early timing belt troubles, and by the mid- to late-‘90s, timing belts were used on the majority of automobile engines. Belt-service intervals became longer, and consumers were getting used to this being a part of normal maintenance. But you still cannot ignore the replacement interval, and was it possible times were changing again? The Old Ball and Chain As we said “Happy New Year” to a whole new century, engine technology was a freight train out of control. Materials and manufacturing were better, RPMs were higher, turbochargers were boosting like never before and horsepower wars like we hadn’t seen since the ‘60s were heating up again. Smaller engines were producing more power than ever, and variable valve timing was pushing engine performance to the limit. Just like that, engine design required something that was narrower, more durable and more dependable than a timing belt, and consumers no longer wanted the associated maintenance. Hello chains. As of the last decade, timing chains have risen back to the top. Design is far different than that of old, with modern chains traveling around awkward paths of sprockets, hydraulic tensioners and chain guides, offering a high level of dependability and performance. But they couldn’t do it without one critical thing on their side: lubricant technology. A primary reason for timing-chain wear always has been related to lack of oil changes, lower-quality oil, and poor or non-existent positive crankcase ventilation (PCV) systems, which wreaks havoc on engine oil. Modern engine oil is not only far superior than it was just a few decades ago, but PCV technology also is eliminating the majority of blow-by-related contaminants and moisture from building up, resulting in cleaner oil and better lubrication throughout the engine. Timing chains and variable valve timing systems are dependent on clean, healthy lubrication and now they have it, but then again, does everyone change oil as often as they should? Talk to the Techs Timing belts generally are easier to service. This is primarily because they’re located on the outside of the engine and run dry, with no lubrication. When replacing a belt, there’s less cleanup and no time required to reseal engine covers. On the other hand, the engine water pump is frequently driven by the timing belt, so when you replace it, it’s a good practice to replace the pump, as well as any tensioners or rollers. Timing belts came into prominence along with the inline four-cylinder engine. What this brought was more than just cam/crank timing, but also balance shafts and intermediate shafts that often drove distributors and oil pumps. These weren’t hard to work with, but had to be timed correctly during belt replacement. As the timing belt migrated to V-configuration engines, it became a lot longer with additional rollers and a more difficult installation, plus some components such as thermostats were all of a sudden underneath. Some things got better, some got worse. Inspection is an advantage with a timing belt; it’s usually just a couple of bolts and you’re looking right at it. One problem, and a challenge especially on a second-owner vehicle: If the mileage is over that of recommended timing-belt replacement and the owner doesn’t know if it was done, replacement is always recommended. Many belts can look great on the outside but strip the teeth off a day later. The only way to inspect them closely enough to really look at the integrity of the teeth can be to remove them. And then, does it make sense to put the old one back on, and is there a technician who would want to take that gamble? One solution to this is the bright yellow replacement decal that’s included in almost every timing-belt kit, for a technician to fill out and affix under the hood. If only they got used more often. Timing chains, as good as they have become, are not without faults. They can be a bear to inspect and replace, mainly because they’re located inside the engine so they can be lubricated by the engine oil. There’s a lot more cleaning to do and usually a seal or two that needs replaced. Just as with belts, there’s often a water pump that’s driven by the chain that should be replaced. While the chains are more durable and dependable, if oil changes aren’t religious, the guides have a tendency to wear out really quickly. Most guides are steel with some type of nylon or plastic that the chain rides along. Remember the nylon-tooth cam gears? These guides do the same thing and beyond a certain point in wear, the tensioner can no longer take up the slack in the chain. This often leads to a rattling noise and a “Check Engine” light. Most engines still run perfectly fine at this point, with the most common complaint a “Check Engine” light and a cam/crank correlation DTC. Timing-chain replacement is often very expensive due to labor time, but, then again, so is engine repair when a timing belt breaks. They both require special tools at times, so there’s no winner on that argument. And, one more thing: Did we mention the latest technology of belt-in-oil drive systems? Here we go again. So, do you have a preference, or do you agree with my conclusion?

Belt quality and tensioner design improved quickly, eliminating many of the early timing belt troubles, and by the mid- to late-‘90s, timing belts were used on the majority of automobile engines. Belt-service intervals became longer, and consumers were getting used to this being a part of normal maintenance. But you still cannot ignore the replacement interval, and was it possible times were changing again?

The easiest way to drive the camshaft was via a timing belt. Since timing chains suffered from inherent gear wear and stretching, engineers decided that belts were the way to go. They were quieter and lighter than a chain and less expensive to manufacture.

Wheel bearingnoise when accelerating

In the case of timing chains, they sometimes wore quicker than a lot of people realized. What happened when they did? On an old car, nothing right away. At least nothing of which the owner was aware.

The October 3 event will cover key topics facing the automotive industry today and feature a wide range of sessions by prominent industry figures, Northwood University said.

This often leads to a rattling noise and a “Check Engine” light. Most engines still run perfectly fine at this point, with the most common complaint a “Check Engine” light and a cam/crank correlation DTC.

Or would they? A lot of people still say, “They don’t build them like they used to.”  This is true, and coming from someone who is an old-car enthusiast, I’ll defend a level of workmanship that we don’t see in today’s vehicle. But the statement, while true, doesn’t always mean they built them better.

A primary reason for timing-chain wear always has been related to lack of oil changes, lower-quality oil, and poor or non-existent positive crankcase ventilation (PCV) systems, which wreaks havoc on engine oil.

Wheel hubs have very close relationships with anti-lock braking system (ABS) sensors. That's because ABS sensors measure wheel speed. To do this accurately, they need to be close to the wheels without being in the way of all of the moving parts.

Many belts can look great on the outside but strip the teeth off a day later. The only way to inspect them closely enough to really look at the integrity of the teeth can be to remove them. And then, does it make sense to put the old one back on, and is there a technician who would want to take that gamble? One solution to this is the bright yellow replacement decal that’s included in almost every timing-belt kit, for a technician to fill out and affix under the hood. If only they got used more often.

As we said “Happy New Year” to a whole new century, engine technology was a freight train out of control. Materials and manufacturing were better, RPMs were higher, turbochargers were boosting like never before and horsepower wars like we hadn’t seen since the ‘60s were heating up again.

The key to brake system longevity is maintenance. Many vehicle owners don’t realize their brakes should be serviced on a regular basis and there are two primary procedures: maintenance at the wheel and brake fluid changes. As a counter-professional, you can capitalize on selling brake service essentials, and, in addition, proper maintenance will reduce warranty claims caused by lack of this often-forgotten service.

For many years, timing chains were the go-to for engine design. Generally speaking, they were dependable and didn’t require any specific maintenance. They were lubricated by the engine oil, so if you changed it on a regular basis, the timing chain would hold up well.

Seemingly, all was good, but even with the advantages of a timing belt, they required replacement at specific intervals, and the one disadvantage that became known quickly was that if not replaced, they would break with no warning. Simple tensioning systems required adjustment from time to time, and oil leaks also were a problem with timing belts, as they would degrade the rubber quickly and lead to a broken belt. A broken belt could mean a very expensive repair on interference engines. Belt quality and tensioner design improved quickly, eliminating many of the early timing belt troubles, and by the mid- to late-‘90s, timing belts were used on the majority of automobile engines. Belt-service intervals became longer, and consumers were getting used to this being a part of normal maintenance. But you still cannot ignore the replacement interval, and was it possible times were changing again? The Old Ball and Chain As we said “Happy New Year” to a whole new century, engine technology was a freight train out of control. Materials and manufacturing were better, RPMs were higher, turbochargers were boosting like never before and horsepower wars like we hadn’t seen since the ‘60s were heating up again. Smaller engines were producing more power than ever, and variable valve timing was pushing engine performance to the limit. Just like that, engine design required something that was narrower, more durable and more dependable than a timing belt, and consumers no longer wanted the associated maintenance. Hello chains. As of the last decade, timing chains have risen back to the top. Design is far different than that of old, with modern chains traveling around awkward paths of sprockets, hydraulic tensioners and chain guides, offering a high level of dependability and performance. But they couldn’t do it without one critical thing on their side: lubricant technology. A primary reason for timing-chain wear always has been related to lack of oil changes, lower-quality oil, and poor or non-existent positive crankcase ventilation (PCV) systems, which wreaks havoc on engine oil. Modern engine oil is not only far superior than it was just a few decades ago, but PCV technology also is eliminating the majority of blow-by-related contaminants and moisture from building up, resulting in cleaner oil and better lubrication throughout the engine. Timing chains and variable valve timing systems are dependent on clean, healthy lubrication and now they have it, but then again, does everyone change oil as often as they should? Talk to the Techs Timing belts generally are easier to service. This is primarily because they’re located on the outside of the engine and run dry, with no lubrication. When replacing a belt, there’s less cleanup and no time required to reseal engine covers. On the other hand, the engine water pump is frequently driven by the timing belt, so when you replace it, it’s a good practice to replace the pump, as well as any tensioners or rollers. Timing belts came into prominence along with the inline four-cylinder engine. What this brought was more than just cam/crank timing, but also balance shafts and intermediate shafts that often drove distributors and oil pumps. These weren’t hard to work with, but had to be timed correctly during belt replacement. As the timing belt migrated to V-configuration engines, it became a lot longer with additional rollers and a more difficult installation, plus some components such as thermostats were all of a sudden underneath. Some things got better, some got worse. Inspection is an advantage with a timing belt; it’s usually just a couple of bolts and you’re looking right at it. One problem, and a challenge especially on a second-owner vehicle: If the mileage is over that of recommended timing-belt replacement and the owner doesn’t know if it was done, replacement is always recommended. Many belts can look great on the outside but strip the teeth off a day later. The only way to inspect them closely enough to really look at the integrity of the teeth can be to remove them. And then, does it make sense to put the old one back on, and is there a technician who would want to take that gamble? One solution to this is the bright yellow replacement decal that’s included in almost every timing-belt kit, for a technician to fill out and affix under the hood. If only they got used more often. Timing chains, as good as they have become, are not without faults. They can be a bear to inspect and replace, mainly because they’re located inside the engine so they can be lubricated by the engine oil. There’s a lot more cleaning to do and usually a seal or two that needs replaced. Just as with belts, there’s often a water pump that’s driven by the chain that should be replaced. While the chains are more durable and dependable, if oil changes aren’t religious, the guides have a tendency to wear out really quickly. Most guides are steel with some type of nylon or plastic that the chain rides along. Remember the nylon-tooth cam gears? These guides do the same thing and beyond a certain point in wear, the tensioner can no longer take up the slack in the chain. This often leads to a rattling noise and a “Check Engine” light. Most engines still run perfectly fine at this point, with the most common complaint a “Check Engine” light and a cam/crank correlation DTC. Timing-chain replacement is often very expensive due to labor time, but, then again, so is engine repair when a timing belt breaks. They both require special tools at times, so there’s no winner on that argument. And, one more thing: Did we mention the latest technology of belt-in-oil drive systems? Here we go again. So, do you have a preference, or do you agree with my conclusion?

Timing chains, as good as they have become, are not without faults. They can be a bear to inspect and replace, mainly because they’re located inside the engine so they can be lubricated by the engine oil. There’s a lot more cleaning to do and usually a seal or two that needs replaced. Just as with belts, there’s often a water pump that’s driven by the chain that should be replaced. While the chains are more durable and dependable, if oil changes aren’t religious, the guides have a tendency to wear out really quickly. Most guides are steel with some type of nylon or plastic that the chain rides along. Remember the nylon-tooth cam gears? These guides do the same thing and beyond a certain point in wear, the tensioner can no longer take up the slack in the chain. This often leads to a rattling noise and a “Check Engine” light. Most engines still run perfectly fine at this point, with the most common complaint a “Check Engine” light and a cam/crank correlation DTC. Timing-chain replacement is often very expensive due to labor time, but, then again, so is engine repair when a timing belt breaks. They both require special tools at times, so there’s no winner on that argument. And, one more thing: Did we mention the latest technology of belt-in-oil drive systems? Here we go again. So, do you have a preference, or do you agree with my conclusion?

As of the last decade, timing chains have risen back to the top. Design is far different than that of old, with modern chains traveling around awkward paths of sprockets, hydraulic tensioners and chain guides, offering a high level of dependability and performance. But they couldn’t do it without one critical thing on their side: lubricant technology. A primary reason for timing-chain wear always has been related to lack of oil changes, lower-quality oil, and poor or non-existent positive crankcase ventilation (PCV) systems, which wreaks havoc on engine oil. Modern engine oil is not only far superior than it was just a few decades ago, but PCV technology also is eliminating the majority of blow-by-related contaminants and moisture from building up, resulting in cleaner oil and better lubrication throughout the engine. Timing chains and variable valve timing systems are dependent on clean, healthy lubrication and now they have it, but then again, does everyone change oil as often as they should? Talk to the Techs Timing belts generally are easier to service. This is primarily because they’re located on the outside of the engine and run dry, with no lubrication. When replacing a belt, there’s less cleanup and no time required to reseal engine covers. On the other hand, the engine water pump is frequently driven by the timing belt, so when you replace it, it’s a good practice to replace the pump, as well as any tensioners or rollers. Timing belts came into prominence along with the inline four-cylinder engine. What this brought was more than just cam/crank timing, but also balance shafts and intermediate shafts that often drove distributors and oil pumps. These weren’t hard to work with, but had to be timed correctly during belt replacement. As the timing belt migrated to V-configuration engines, it became a lot longer with additional rollers and a more difficult installation, plus some components such as thermostats were all of a sudden underneath. Some things got better, some got worse. Inspection is an advantage with a timing belt; it’s usually just a couple of bolts and you’re looking right at it. One problem, and a challenge especially on a second-owner vehicle: If the mileage is over that of recommended timing-belt replacement and the owner doesn’t know if it was done, replacement is always recommended. Many belts can look great on the outside but strip the teeth off a day later. The only way to inspect them closely enough to really look at the integrity of the teeth can be to remove them. And then, does it make sense to put the old one back on, and is there a technician who would want to take that gamble? One solution to this is the bright yellow replacement decal that’s included in almost every timing-belt kit, for a technician to fill out and affix under the hood. If only they got used more often. Timing chains, as good as they have become, are not without faults. They can be a bear to inspect and replace, mainly because they’re located inside the engine so they can be lubricated by the engine oil. There’s a lot more cleaning to do and usually a seal or two that needs replaced. Just as with belts, there’s often a water pump that’s driven by the chain that should be replaced. While the chains are more durable and dependable, if oil changes aren’t religious, the guides have a tendency to wear out really quickly. Most guides are steel with some type of nylon or plastic that the chain rides along. Remember the nylon-tooth cam gears? These guides do the same thing and beyond a certain point in wear, the tensioner can no longer take up the slack in the chain. This often leads to a rattling noise and a “Check Engine” light. Most engines still run perfectly fine at this point, with the most common complaint a “Check Engine” light and a cam/crank correlation DTC. Timing-chain replacement is often very expensive due to labor time, but, then again, so is engine repair when a timing belt breaks. They both require special tools at times, so there’s no winner on that argument. And, one more thing: Did we mention the latest technology of belt-in-oil drive systems? Here we go again. So, do you have a preference, or do you agree with my conclusion?

How to tell whichwheel bearingis bad while driving

Car manufacturers have several ways of handling this task. The first is with a "tone ring." A tone ring attaches to the back of the wheel hub and it looks like a gear. With the ABS hub attached to a vehicle, there is an ABS sensor that sits next to the tone ring and measures wheel speed by watching how many teeth pass by the sensor within a certain length of time.

As a counter-professional, you can capitalize on selling brake service essentials, and, in addition, proper maintenance will reduce warranty claims caused by lack of this often-forgotten service.

Carwheel bearing

Smaller engines were producing more power than ever, and variable valve timing was pushing engine performance to the limit. Just like that, engine design required something that was narrower, more durable and more dependable than a timing belt, and consumers no longer wanted the associated maintenance. Hello chains.

Timing-chain replacement is often very expensive due to labor time, but, then again, so is engine repair when a timing belt breaks. They both require special tools at times, so there’s no winner on that argument. And, one more thing: Did we mention the latest technology of belt-in-oil drive systems? Here we go again. So, do you have a preference, or do you agree with my conclusion?

Modern engine oil is not only far superior than it was just a few decades ago, but PCV technology also is eliminating the majority of blow-by-related contaminants and moisture from building up, resulting in cleaner oil and better lubrication throughout the engine.

Inspection is an advantage with a timing belt; it’s usually just a couple of bolts and you’re looking right at it. One problem, and a challenge especially on a second-owner vehicle: If the mileage is over that of recommended timing-belt replacement and the owner doesn’t know if it was done, replacement is always recommended.

Wheel bearingreplacement cost

A timing chain, just like a belt, is there for one reason: to connect the crankshaft to the camshaft at exact points so the valves open and close at the correct time for engine operation. A traditional, old-school timing chain was tight upon installation, and the overall timing set consisted of a crankshaft gear, a camshaft gear and a chain. There was no adjustment or no tensioner. When the chain or the drive gears began to wear, engine performance would suffer, but it would degrade slowly, and most vehicle owners had no idea there was a problem. They wouldn’t know at all until they started to get a hard-start or no-start symptom. And why? There was no crank sensor or cam sensor, and no computer to translate the signals into a crank/cam correlation diagnostic trouble code (DTC). So, we just drove the cars until they wouldn’t drive any more. Early engine design was split between gears or chains, but chains ultimately became more popular because they took up less space and ran quieter, and by the early ‘80s, the majority of cars produced had timing chains. An evolutionary change of timing-chain design included nylon-tooth cam gears. They ran quieter than a traditional steel gear, but they wore out a lot quicker and created problems long before vehicle owners expected, which didn’t do much for their reputation. The tried-and-true timing chain was simple and generally dependable, but times were changing. Buckle Your Belt As the ‘80s rolled on, electronics, emission controls and technology were on solid cruise control and like flipping a switch, timing belts were suddenly in the picture. Although timing-belt-driven overhead camshaft engines weren’t new by any means, the value of the design began to be recognized and auto manufacturers started to change over to this concept. The camshaft was now located on the cylinder head, which eliminated push rods and, on some designs, the rocker arms were eliminated as well, saving weight, lowering cost, reducing valvetrain inertia and making multi-valve designs possible. The easiest way to drive the camshaft was via a timing belt. Since timing chains suffered from inherent gear wear and stretching, engineers decided that belts were the way to go. They were quieter and lighter than a chain and less expensive to manufacture. The tensioning systems were simple, and the belts remained tight for a long time without wearing the cam or crank gear. Seemingly, all was good, but even with the advantages of a timing belt, they required replacement at specific intervals, and the one disadvantage that became known quickly was that if not replaced, they would break with no warning. Simple tensioning systems required adjustment from time to time, and oil leaks also were a problem with timing belts, as they would degrade the rubber quickly and lead to a broken belt. A broken belt could mean a very expensive repair on interference engines. Belt quality and tensioner design improved quickly, eliminating many of the early timing belt troubles, and by the mid- to late-‘90s, timing belts were used on the majority of automobile engines. Belt-service intervals became longer, and consumers were getting used to this being a part of normal maintenance. But you still cannot ignore the replacement interval, and was it possible times were changing again? The Old Ball and Chain As we said “Happy New Year” to a whole new century, engine technology was a freight train out of control. Materials and manufacturing were better, RPMs were higher, turbochargers were boosting like never before and horsepower wars like we hadn’t seen since the ‘60s were heating up again. Smaller engines were producing more power than ever, and variable valve timing was pushing engine performance to the limit. Just like that, engine design required something that was narrower, more durable and more dependable than a timing belt, and consumers no longer wanted the associated maintenance. Hello chains. As of the last decade, timing chains have risen back to the top. Design is far different than that of old, with modern chains traveling around awkward paths of sprockets, hydraulic tensioners and chain guides, offering a high level of dependability and performance. But they couldn’t do it without one critical thing on their side: lubricant technology. A primary reason for timing-chain wear always has been related to lack of oil changes, lower-quality oil, and poor or non-existent positive crankcase ventilation (PCV) systems, which wreaks havoc on engine oil. Modern engine oil is not only far superior than it was just a few decades ago, but PCV technology also is eliminating the majority of blow-by-related contaminants and moisture from building up, resulting in cleaner oil and better lubrication throughout the engine. Timing chains and variable valve timing systems are dependent on clean, healthy lubrication and now they have it, but then again, does everyone change oil as often as they should? Talk to the Techs Timing belts generally are easier to service. This is primarily because they’re located on the outside of the engine and run dry, with no lubrication. When replacing a belt, there’s less cleanup and no time required to reseal engine covers. On the other hand, the engine water pump is frequently driven by the timing belt, so when you replace it, it’s a good practice to replace the pump, as well as any tensioners or rollers. Timing belts came into prominence along with the inline four-cylinder engine. What this brought was more than just cam/crank timing, but also balance shafts and intermediate shafts that often drove distributors and oil pumps. These weren’t hard to work with, but had to be timed correctly during belt replacement. As the timing belt migrated to V-configuration engines, it became a lot longer with additional rollers and a more difficult installation, plus some components such as thermostats were all of a sudden underneath. Some things got better, some got worse. Inspection is an advantage with a timing belt; it’s usually just a couple of bolts and you’re looking right at it. One problem, and a challenge especially on a second-owner vehicle: If the mileage is over that of recommended timing-belt replacement and the owner doesn’t know if it was done, replacement is always recommended. Many belts can look great on the outside but strip the teeth off a day later. The only way to inspect them closely enough to really look at the integrity of the teeth can be to remove them. And then, does it make sense to put the old one back on, and is there a technician who would want to take that gamble? One solution to this is the bright yellow replacement decal that’s included in almost every timing-belt kit, for a technician to fill out and affix under the hood. If only they got used more often. Timing chains, as good as they have become, are not without faults. They can be a bear to inspect and replace, mainly because they’re located inside the engine so they can be lubricated by the engine oil. There’s a lot more cleaning to do and usually a seal or two that needs replaced. Just as with belts, there’s often a water pump that’s driven by the chain that should be replaced. While the chains are more durable and dependable, if oil changes aren’t religious, the guides have a tendency to wear out really quickly. Most guides are steel with some type of nylon or plastic that the chain rides along. Remember the nylon-tooth cam gears? These guides do the same thing and beyond a certain point in wear, the tensioner can no longer take up the slack in the chain. This often leads to a rattling noise and a “Check Engine” light. Most engines still run perfectly fine at this point, with the most common complaint a “Check Engine” light and a cam/crank correlation DTC. Timing-chain replacement is often very expensive due to labor time, but, then again, so is engine repair when a timing belt breaks. They both require special tools at times, so there’s no winner on that argument. And, one more thing: Did we mention the latest technology of belt-in-oil drive systems? Here we go again. So, do you have a preference, or do you agree with my conclusion?

Badwheel bearingsymptoms

The other common method of measuring wheel speed is by adding the whole entire ABS sensor to the inside of the wheel hub itself. This can be a blessing and a curse. It simplifies the ABS system so that when an ABS sensor fails, the entire hub needs to be replaced with it. Pretty wasteful if you have a perfectly good working hub. Another ABS system design that skips the hub connection altogether and places the tone ring on the axle instead of the wheel hub. All these methods work great, you just need to make sure that you use the proper parts that are designed to work with ABS. Without that tone ring attached to the wheel hub or axle, the ABS light will turn on, and your vehicle won't stop as it was designed to.

The wheel bearing is a round metal part found in the center of the hub that connects the axles to the wheels and helps them turn smoothly. They usually have greased metal balls encased between two rings called races. Have you ever turned the steering wheel of your car and heard that unmistakable "whirring" noise from a bad wheel bearing? Worn wheel bearings have been making this noise for as long as they have existed. As they wear out, excess play develops in the bearing. This excess play, along with dust, dirt, and debris sneaking its way inside, will end up damaging the internal bearing surfaces. Once the wheel bearing surfaces are damaged, they have zero chance of survival. The wheel bearing's condition will worsen until it finally self destructs in spectacular fashion. As you can imagine, the ideal situation is to replace the wheel bearing long before it reaches the point of destruction.

Average life ofwheelbearings

When the chain or the drive gears began to wear, engine performance would suffer, but it would degrade slowly, and most vehicle owners had no idea there was a problem. They wouldn’t know at all until they started to get a hard-start or no-start symptom. And why? There was no crank sensor or cam sensor, and no computer to translate the signals into a crank/cam correlation diagnostic trouble code (DTC). So, we just drove the cars until they wouldn’t drive any more.

Although timing-belt-driven overhead camshaft engines weren’t new by any means, the value of the design began to be recognized and auto manufacturers started to change over to this concept. The camshaft was now located on the cylinder head, which eliminated push rods and, on some designs, the rocker arms were eliminated as well, saving weight, lowering cost, reducing valvetrain inertia and making multi-valve designs possible.

Once you pull the wheels off of a car, the first thing that you see is the wheel hub staring straight back into your eyes. That's because the hubs are the part that the wheels bolt on to. They are round, have wheel studs sticking out of them, and are designed to spin with heavy loads sitting on them at all times. Guess what else bolts onto the hub? Brake rotors of course! Wheel hubs can be driven by the axles or just freewheeling. Every wheel hub is, in some way, connected to a wheel bearing. They are either pressed or bolted together, and they frequently come as one "wheel hub and bearing" assembly. This makes installation significantly easier and cheaper. Just pull the old hub and bearing assembly off, and throw the new one on. No heavy duty pressing or special tools are needed.

As soon as the call ends, or the online order is sent, we are “on the clock,” even if it is only the customer’s internal clock.

Timing belts generally are easier to service. This is primarily because they’re located on the outside of the engine and run dry, with no lubrication. When replacing a belt, there’s less cleanup and no time required to reseal engine covers. On the other hand, the engine water pump is frequently driven by the timing belt, so when you replace it, it’s a good practice to replace the pump, as well as any tensioners or rollers.

While the chains are more durable and dependable, if oil changes aren’t religious, the guides have a tendency to wear out really quickly. Most guides are steel with some type of nylon or plastic that the chain rides along. Remember the nylon-tooth cam gears? These guides do the same thing and beyond a certain point in wear, the tensioner can no longer take up the slack in the chain.

An evolutionary change of timing-chain design included nylon-tooth cam gears. They ran quieter than a traditional steel gear, but they wore out a lot quicker and created problems long before vehicle owners expected, which didn’t do much for their reputation. The tried-and-true timing chain was simple and generally dependable, but times were changing.

Wheel hubs themselves rarely have issues because they are simple blocks of steel. The most common reason to replace a wheel hub is because the wheel bearing that is attached to it has failed. Wheel bearings can fail because of age, dirt and water contamination, or improper installation. Most hubs that are driven by axles require a very specific torque when installing. If that torque is too tight or too loose, the life of the wheel bearing can become shortened. That said, most wheel hub and bearing assemblies are very DIY friendly. If you can replace brakes yourself, you probably won't have any trouble replacing a wheel hub yourself either.