AUTONET TV

Out of Joint (CV Joint and Boot Replacement)

If you have a front-wheel-drive vehicle, it has components called CV joints which enable you to turn your wheels smoothly. The CV stands for “constant velocity.” In essence, it’s a set of gears that connect a shaft that allows power from the transmission to be sent to the wheels.  When you turn the wheels, no matter what angle, the input velocity rotation will be equal to the output. Thus, the name, CV (constant velocity) joint. Other vehicles with 4-wheel drive and all-wheel drive also use CV joints.  

If one of your CV joints isn’t working right, you may find your vehicle difficult to handle.  If one breaks, your vehicle may stop moving.  So, it’s important that CV joints be in top working condition.  The joints need a lot of lubrication, so they are surrounded by grease.  There’s a rubber enclosure around them called the boot which holds the grease in and protects CV joints from the elements. 
 
The biggest problems come when one of those rubber boots cracks.  Water and dirt can then get into the joint, causing it to wear down and lose all its vital lubrication.  It’s important to have your CV joints inspected regularly so a technician can spot cracks before the CV joints are ruined.  Sometimes just the boot can be replaced before any major damage is done.  But when the joint does go bad, it must be replaced.  

Signs your CV joint needs changing out? You might hear a clicking sound when you turn if the CV joint is worn out. You might notice some thick, black grease around your wheel or on the pavement where you park your vehicle.  You might also feel your vehicle vibrate when you’re going fast.

If you suspect you might have a bad CV joint, bring your vehicle in so a technician can determine what’s going on.  Keep your CV joints in good shape and reduce the risk of them seizing up at an inopportune time so you can avoid being stranded.

McLearen Shell
3043 Centreville Road
Herndon, VA 20171
(703) 318-7744
http://www.mclearenshell.com

U and your U-Joints (Lubricate U-Joints)

If your vehicle’s power goes to the rear wheels, then you have something called U-joints in the drivetrain. U-joints are connectors that allow the rotating power from your vehicle’s engine to deliver its power through a driveshaft to make the rear wheels rotate.  You need U-joints because the surfaces you drive on aren’t perfectly flat, and the driveshaft has to allow for some flexibility when you are traveling over uneven surfaces.

As you can imagine, the U-joints have to move and flex a lot as your vehicle is going down the road.  They have bearings in them to allow that flexibility, and those bearings are lubricated when your vehicle is made.  Some U-joints have lifetime lubrication and are not designed to be serviced.  When they fail, they have to be replaced.  Others have grease fittings on them that need periodic lubricating by a technician at intervals recommended by your vehicle’s manufacturer. 

There are signs you can look for that your U-joints need attention.  You may hear a clunk when the gears shift into drive or reverse.  You may feel your vehicle vibrate as you move down the road.  Other signs are leaks at the back of your transmission or a banging sound right before you lose power.  Sometimes, though, if you wait until you notice these symptoms, the U-joints may already be damaged.  

That’s why it’s important that your vehicle’s U-joints be periodically inspected and lubricated.  At the same time, a technician should thoroughly inspect the driveshaft and other connected components.  

Keep your U-joints in good shape, and both of U will continue to enjoy years of reliable transportation.

McLearen Shell
3043 Centreville Road
Herndon, VA 20171
(703) 318-7744
http://www.mclearenshell.com

Why You Have an O2 Sensor (Oxygen Sensor)

If someone asked you what gas made up the largest portion of the atmosphere, what would you guess? Well, it's not oxygen; it only makes up 20.9 percent.  But since we're talking about oxygen, you should know that your vehicle uses oxygen sensors to make sure your engine is running the way it should.

The oxygen sensors measure how much oxygen is in your exhaust.  If there's too much, it means there's a problem with the mixture of fuel and air.  The sensor sends signals to computers in your engine and adjusts the mixture so it maximizes performance and efficiency.  It does this constantly. 

Many vehicles have multiple oxygen sensors.  Some have one close to the engine, another close to the muffler.  Two measurements are better than one since they allow readings to be more accurate.  You may have a vehicle with a dual exhaust, so you'd have twice as many oxygen sensors.

Your oxygen sensors can fail.  One thing that can damage them is contamination from bad fuel.  The sensors can simply wear out, though they usually last a long time.  It's not unusual for an oxygen sensor to last 100,000 miles/160,000 km. One more thing that can cause an oxygen sensor to fail is residue from an engine that's burning oil.  Plus contaminants from the road like salt can also cause problems. 

Here are some signs that your oxygen sensors might be failing.

• The Check Engine light goes on.  In this case, your service facility can plug in a device that will read the code in your engine's computer to see if that's the problem.
• The engine is running roughly.
• Black, sooty smoke is coming out of your tailpipe.
• Your fuel economy is noticeably lower than it used to be.

Head to your service facility and tell your advisor what symptoms your vehicle is experiencing.  They have the equipment and training to track down the issue.  Note that simply replacing the oxygen sensor is often not enough since it doesn't get to the root of the problem; other repairs may be needed. 

So make sure your oxygen sensors are working the way they should be.  Oh, and back to the question of what gas makes up most of the Earth's air?  It's nitrogen, which comprises 78 percent of the air we—and our engines—breathe.

McLearen Shell
3043 Centreville Road
Herndon, VA 20171
(703) 318-7744
http://www.mclearenshell.com

What is a TSB? (Technical Service Bulletins)

If your vehicle had something in its design or production that the manufacturer had figured out had an unanticipated problem, you'd want to know about it. And you'd want it fixed. There is something that can help drivers with just such a scenario. It's called a Technical Service Bulletin, or TSB.

Here's what a TSB is. Vehicle design and manufacturing is a very complex process. Aftrer every vehicle is introduced, the more units there are on the road, the more likely weaknesses in parts or design will start to show up.

Automakers gather data on the issues and how best to fix them. Then they send out TSBs (usually in the first year of the new model) so technicians will know to look for those problems and what to do about them. There may be more than one cause of a problem with a vehicle so there may be more than one TSB for an issue.

A TSB can be issued for anything from failing water pumps to strange noises to smelly headliners. A TSB and a recall aren't the same thing. A recall is issued if there's a problem that could cause harm to people or if it creates illegal emissions. The manufacturer pays for a safety defect to be fixed, and the repair is usually performed at a dealership.

But when a Technical Service Bulletin is issued, it's because there's a pattern of some system not working the way it should. If a vehicle is under warranty and the problem can be diagnosed in a specific vehicle, the manufacturer will probably pay for the repair. But there may be limits. Take one case with certain models of a minivan. Some wheel bearings were failing prematurely, so the manufacturer extended the warranty on them to 5 years or 90,000 miles/145,000 km. After that, the owner bore the cost. In some cases, a manufacturer will reimburse owners for a repair already done at an independent service facility.

You may have a vehicle that is no longer covered by a warranty but a TSB has been issued for a certain problem. In that case, any service facility can perform the service. At McLearen Shell, your service advisor will have access to TSBs that have been issued for your vehicle's year and model. They will help the technician diagnose it if your vehicle has the issue. The TSB will also have advice for the best repair procedure to get your vehicle working the way it should.

McLearen Shell
3043 Centreville Road
Herndon, VA 20171
(703) 318-7744
http://www.mclearenshell.com