Los Altos Auto Repair

Scratching your head? Don't worry, if you don’t know what a differential is – you will in a moment. That fact is that if you drive a car anywhere in Los Altos, CA, you have a differential. Whether your vehicle is front-wheel drive, rear-wheel drive or four-wheel drive, you have a differential. You might even have two or three.

Not surprisingly, a differential’s job is to compensate for differences. Specifically the differences in wheel speed when turning. For instance, imagine taking a corner near your Los Altos, CA home. Your inside wheel has a shorter distance to travel than the outside wheel as you turn the corner. That means that your outside wheel has to turn faster to keep pace with the inside wheel.

The differential allows the wheels to turn at different speeds while still providing power to your vehicle. Without a differential, our tires would scrub and hop along the pavement during turns like the early cars.

Ever noticed the big bulge in the middle of the rear axle on trucks? That’s the differential. Rear-wheel drive vehicles have a differential in back. Most four-wheel drive trucks and SUVs will also have a similar differential on the front axle. Front-wheel drive vehicles’ differential is called a transaxle because it combines the differential and transmission in one unit. An all-wheel drive vehicle will have a differential or transfer case that adjusts for speed differences between the front and rear drive wheels.

It can seem a little complex to some Los Altos drivers - but you can see that all of the engine’s power is routed through your differentials. They’re strong enough to handle the work, but- we've said it before - they need to be properly lubricated in order to stay strong. So from time to time, you need to have your differential serviced at Allied Auto Works. The used fluid is drained and replaced with clean fluid. Some auto manufacturers advise certain differentials to have special additives installed.

Get your differential serviced at our Los Altos automotive center:
Allied Auto Works
2073 Grant Road
Los Altos, CA 94024
650.968.7227

Recommendations for the time and mileage interval for servicing your differential, can vary greatly by vehicle. A front-wheel drive vehicle’s transaxle will need servicing more frequently than the rear differential on a pick-up truck, so check with your Los Altos, CA Allied Auto Works service advisor or your auto manufacturers owner’s manual for recommendations.

How and where you drive in Los Altos will have an impact as well. If you drive on dirt roads or through streams around Los Altos, CA, you’ll need to service the differential much sooner than if you always stay on expressways.

Today Allied Auto Works is talking about the proper fluids for your vehicle. It's become more complicated with changes in automotive design and manufacturing. It's not that people in CA are confused as much as they don't realize how much things have changed in recent years.

If you have questions about the fluids in your vehicle, please don't hesitate to stop by Allied Auto Works. You can find us on 2073 Grant Road in Los Altos, CA 94024.
Just give us a call at 650.968.7227

Let's take engine oil. Twenty or thirty years ago, there were just a handful of different weights of oil. The weight of an oil is a scientific measure of its properties, particularly its viscosity or thickness.

It was common in those days to use a lighter weight oil in the winter when it's cold outside. That way the oil would be able to splash around inside the engine and protect the parts before it was fully warmed up. And a heavier weight oil would be used in the summer. The thicker oil wouldn't thin out too much in the summer heat and vaporize in the engine.

Modern valve trains have become very complicated with more moving parts and small passages than ever before. The valve train is in the top of the engine, so when the car has been turned off for a while, the oil tends to run down to lower areas and the valve train parts are vulnerable at start-up, before the oil starts circulating.

So new weights of oil have been introduced to meet the engineering specifications of these newer engines.

Manufacturers are recommending specific weights of oil. The recommendation is often printed on the oil fill cap. It's certainly in the owner's manual. Of course, your Los Altos CA auto service center can look it up for you.

It's more important than ever to have the correct weight of oil. The wrong weight could actually harm the engine.

Other fluids are also becoming more sophisticated. In the last few years new types of transmission, power brake fluid and coolant have all been introduced for some of the same reasons as for engine oil.

In addition, vehicle manufacturers are now using a wider variety of materials in these systems. Looking at the cooling system as an example, it used to be that the parts were all made out of steel or iron and the hoses were rubber. Now, some parts are plastic, aluminum or other materials.

So the anti-corrosion additives contained in the coolant, or anti-freeze, need to be different in order to protect the different materials used to make the cooling system. If you use the wrong coolant that wasn't formulated to protect your plastic cooling system parts, they could become corroded and fail. And if you're using the wrong coolant, your cooling system won't be covered under warrantee. So it's important to use the right coolant and to not mix different types.

Your owner's manual or your Los Altos CA service advisor at Allied Auto Works can make sure you're using the right type. You may have heard of universal coolant. Universal, or global, coolant can be added to other types without harmful reactions. That's OK for an emergency top off, but following your manufacturer's recommendation for your sedan or other auto type is always a safe bet.

In the area of brake fluid, there are a couple of new formulations. It's important to remember that the new ones aren't better than the old ones. They're just different formulations for different vehicles. So if your vehicle calls for DOT 3, using DOT 4 or DOT 5 is not an upgrade. Use the recommended formula.

There are fluid formulations for vehicles with higher mileage. These are special engine oil, transmission fluid, and so on that contain additives to condition and restore seals and gaskets in older engines.

They're fine to use as long as they're a variant of the proper fluid. In other words you can use a high mileage engine oil as long as it's also the correct weight recommended by the manufacturer. Same goes for transmission fluid; as long as it's the right type for your transmission.

What type of technology do you use? Do you prefer an 8-track tape or an iPod? When it comes to winter tires, much of the public's perception dates back to when 8-track was the best way to listen to the Bee Gees.

Twenty years ago, winter tires differed from highway tires only in their tread design. We called them snow tires back then and they had big, knobby lugs that were designed to give good traction in deep snow. They had the same rubber compound as regular tires and they weren't very good on ice, packed snow or wet roads. They were not even very good on dry roads. They really helped in deep or loose snow, but they did a poor job the rest of the time. They were loud and rode hard. You couldn't wait to get them off in the spring.

Then all-season tires started to come along. All-season tires are really a compromise between summer and winter performance. They have acceptable hot weather ride and tread life, and you can get through mild winter road conditions OK. But there are some really good reasons to consider winter tires.

Modern winter tires do a terrific job in a wide range of winter conditions. First of all, below 45 degrees Fahrenheit, regular tires become hard and inflexible. That means they don't provide the road grip you need. Even if you don't live somewhere with a lot of snow, but it still gets below 45 degrees in the winter, you will be safer with winter tires.

In addition, they are specifically designed to more effectively move snow and water. That's the key to traction on ice, packed snow and wet roads. They use a micro-pore compound that allows the tire to bite into ice and snow. They also use wider grooves that run around the circumference of the tread to expel snow from the tire better. The lugs and grooves on winter tires have a special shape that throws the packed snow out of the tread as the tire turns. The tread is then open when it comes back in contact with the road and can provide good traction.

Winter tires also have a lot of sipes. Sipes are thin slits in the tread. The edge of the sipes grab ice and packed snow to provide tons of traction and to expel water and slush out of the tread. winter tires have a rounder casing to cut into the snow's surface. The treads on regular summer tires can actually get packed with snow instead and become very slick. winter tires offer 25% to 50% more traction than all-season tires. And when it comes to stopping power, all-season tires take 42% longer to stop than winter tires. Sometimes that's the difference between getting home safely and spending the night in a snow bank.

Now back when the 8-track was king, you just put snow tires on the drive wheels. That worked out OK because the rubber compound was essentially the same. Now, winter tires provide so much more traction than all-season or summer tires, that there's a huge difference between the traction at the front and rear ends of the car if you only put winter tires on the drive wheels.

For example: if you take a corner on an icy road and the rear end starts to slide out, essentially the rear is trying to pass the front because it's going faster. If you have high traction winter tires only on the front, they are going to be much more effective at transferring cornering grip and stopping power to the front wheels. This will actually cause the rear end to whip out even more.

That's why tire manufactures instruct their dealers that they must install winter tires on the rear wheels as well whenever they put winter tires on the front end of any vehicle. It's a major safety concern. It's strongly recommended that winter tires be installed on all four wheels on rear wheel drive vehicles as well. The front tires do most of the steering and braking work - it only makes sense that you provide the front end with the best traction you can.

People often assume that if they have four-wheel drive or all-wheel drive they don't need winter tires on all four wheels. Would you intentionally disconnect the four-wheel drive in poor road conditions? Of course you wouldn't, but that's essentially what you do if you only put winter tires on one end. It only makes sense to have the same level of traction and control at all four corners.

The province of Quebec in Canada has issued a law requiring all passenger vehicles, taxis and rental cars with Quebec license plates to install a full set of four winter tires between November 15th and April 1. It's that important.

Many modern cars have traction control and anti-lock brakes so people may think that they don't need winter tires. But you need traction to accelerate, steer and stop. The tires provide the traction so that the traction control and anti-lock brakes have something to work with.

Look for tires with the symbol of a mountain with a snowflake in it. This means the tire complies with the severe snow standard. All-season tires will have an M&S, for mud and snow, on the sidewall.

So when the temperatures drop below 45 degrees, be sure you have a set of four winter tires for maximum performance in snow, packed snow, ice, wet and dry roads. Your tire professional can help you find the right winter tire for your vehicle and driving needs.

A lot of Los Altos motorists have asked whether or not they should use their severe service maintenance schedule, which is listed in their car owners' manual. It can be somewhat confusing, so we decided to consult an expert. Cricket Killingsworth is from QMI/Heartland, a manufacturer of automotive products and fluids. She's been in the automotive business for 24 years and is a speaker, a trainer, and a writer.

Cricket says there's so much confusion on this topic because, "Most owners' manuals actually have two maintenance schedules. Sometimes these are called 'regular service' and 'severe service'. Sometimes they're simply called Schedule 1 and Schedule 2. A severe service schedule recommends that things like an oil change, air filter replacement, and transmission service be done more often: either in fewer miles or in less time."

Foreign and domestic car makers create a specific schedule for each vehicle they manufacture. So there isn't one generic schedule that applies to all cars. In addition to your owners' manual, Los Altos automotive repair centers (including Allied Auto Works) subscribe to information services that provide the maintenance schedules for every vehicle - so they can help you know when to take care of needed services. Below is a typical definition for severe service.

• Most trips are less than four miles
• Most trips are less than ten miles and outside temperatures are below freezing
• You drive regularly in very hot CA weather
• The engine is at low speed most of the time (not on the expressway)
• Stop and go driving
• You drive in in dusty or muddy conditions
• You routinely tow a trailer, haul heavy loads or carry a car-top carrier

It's common sense: Just a few minutes at expressway speeds allows the moisture in the oil to evaporate. Very short trips, or trips of less than ten miles when it's very cold in Los Altos, don't allow the engine to heat up enough to get rid of the water. And water in the oil leads to damaging sludge. Also, towing and heavy loads raise operating temperatures and cause fluids to break down faster. Dusty and muddy driving means that more dirt will get past the air filter to contaminate the fuel system and engine oil.

The bottom line is that you need to decide for yourself if the regular or severe service schedule is right for you, based on your driving habits. Look at your owners' manual, or talk with your Allied Auto Works service advisor who can help you know which schedule to follow. Allied Auto Works is located at 2073 Grant Road, Los Altos CA.

Here is what a fleet manager said recently: "Since city miles are generally tougher on vehicles than highway miles, we use the manufacturer's severe service schedule as the basis for our preventative maintenance program. We massage those schedules over time, increasing or decreasing the service intervals so that they make the most sense. There is a little bit of art to go along with the science."

Make an honest evaluation of your driving habits. Unless you do mostly CA highway driving in moderate weather, you'll likely have a fairly good amount of severe service mixed in. Some Los Altos motorists just want to play it safe and follow the severe service recommendations, rather than analyzing how they drive each month.

Hello Los Altos auto owners, let's talk about your often-unnoticed but extremely important PCV valve. The energy from exploding fuel is what powers your engine. But some of the vapors from the explosions escape into the lower part of the engine, called the crankcase. The crankcase is where your engine oil hangs out. These gases are about 70% unburned fuel. If the gases were allowed to stay in the crankcase, they would quickly contaminate the oil and turn it to sludge. Los Altos folks know that sludge is one of the biggest enemies of your engine, clogging it up, eventually leading to expensive failures. Also, the pressure build up would cause seals and gaskets to blow out. Therefore, these gases need to be vented out.

Pre-1963, gasoline engines had a hose that let the poisonous fumes vent out into the air. In 1963, the federal government required gas engines to have a special one-way valve installed to help reduce dangerous emissions. (Can you imagine how polluted our Los Altos air would be if every car had been releasing those poisonous fumes for the last fifty years?) Diesel engines are not required to have these valves.

The positive crankcase ventilation, or PCV, valve routes crankcase gases through a hose and back into the air intake system where they are re-burned in the engine. Fresh, clean air is brought into the crankcase through a breather tube. It's really a pretty simple system, but it does the job. The re-circulating air removes moisture and combustion waste from the crankcase, preventing sludge. This extends not only the life of your oil, but the engine as well. The PCV relieves pressure in the crankcase, preventing oil leaks.

Eventually, the PCV valve can get gummed up. Then it can't move enough air through the engine to keep it working properly. If the PCV valve is sticking enough, you could have oil leaks, excess oil consumption and a fouled intake system. If you experience hesitation or surging or an oil leak, it may be a sign of PCV valve problems. Your owners' manual may give a recommendation for when the PCV valve should be replaced - usually between 20,000 mi/32,000 km and 50,000 mi/80,000 km. Unfortunately, some manufacturers don't list a recommendation in the manual, so it can be easy to overlook.

Many PCV system problems can be diagnosed with an automotive analysis by your personal Allied Auto Works service professional. Fortunately, PCV valve replacement is both quick and inexpensive at Allied Auto Works. Proper oil changes will greatly extend the life of the PCV valve. Skipping a few recommended oil changes can allow varnish and gum to build up in the valve, reducing its efficiency. So now when your Los Altos service technician tells you its time to replace your PCV valve, you will know what he's talking about. If you have had your car for a while and this is the first you've ever heard of a PCV value, ask your service professional to check yours out or call Allied Auto Works at 650.968.7227.

The last new American car sold in Los Altos with a carburetor rolled out of the CA dealership in 1990. Since then, all new vehicles here in Los Altos and nationally have had fuel injectors. In very simple terms, a fuel injector is a valve that squirts fuel into your engine. Your engine control computer tells the fuel injector how much gas to deliver as well as the precise time it should be delivered. Of course this happens thousands of times a minute. Fuel injectors deliver fuel far more precisely than carburetors. That translates into better gas mileage and more power. Virtually all fuel injectors for gas engines are known as port fuel injectors because they deliver the fuel to a port just outside the cylinder. Port fuel injectors operate at about 40 to 80 pounds per square inch of pressure.

A few vehicle manufacturers have introduced gas direct injection systems on some engines recently. These systems inject the gas directly into the cylinders under very high pressure - hundreds of times the pressure of port injection systems. Although more complicated, direct injection technology promises greater power with improved fuel economy, so Los Altos drivers can expect to see more of it in the future.

As you can see, the level of precision required of your fuel injectors is very high. They need to be operating properly in order for your car to run right.

High temperatures under your hood and variations in Los Altos gas quality cause fuel injectors to become fouled with wax, dirt, and carbon. Injectors can become partially clogged, preventing them from delivering the proper amount of fuel at the correct pressure. The design of each engine requires a specific spray pattern from the fuel injector that might be altered when the injector is dirty. When injectors are dirty, the fuel doesn't burn as efficiently resulting in poor gas mileage and loss of power. So it is important to keep your sedan fuel injectors clean.

Skilled service technicians at Allied Auto Works in Los Altos can perform a fuel system service for you. (Visit contact-us.) That is a fuel system service - not just fuel injector cleaning. That is because the fuel has a lot of ways to become dirty or contaminated between the Los Altos gas pump and your fuel injectors. A fuel system service starts with a fuel filter replacement. This filter cleans the gas as it leaves the tank. The various parts of the fuel intake system need to be cleaned from time to time to remove harmful gum, deposits and varnish. Finally, the fuel injectors are cleaned so that they operate properly and deliver the right amount of fuel at the right time.

Your personal Allied Auto Works service specialist uses a process for cleaning your sedan fuel system that includes state-of-the-art cleaning chemicals as well as some old fashioned scrubbing. Proper maintenance of your fuel system means that you will enjoyed improved gas mileage, enjoy strong performance and prevent pricey repairs down the road.

Whenever they hear the term "exhaust service," most Los Altos people think about exhaust pipes and mufflers. Well, actually, exhaust service at Allied Auto Works is a lot more comprehensive these days. For example, catalytic converters were mandated in 1976 and on-board emission control computers in 1990. Governmental emissions requirements have forced car makers to come up with much more sophisticated ways to comply with environmental regulations.

Exhaust service has really become exhaust and emissions service. High-tech computer controlled emissions devices are now a big part of exhaust service. Because it is so sophisticated, your vehicle manufacturer recommends you have your emission system checked out by a qualified Los Altos exhaust technician regularly to make sure everything is working right - usually every 6 months or 10,000 miles/16,000 kilometers.

If your Check Engine light comes on, especially if it's flashing, get your car looked at right away. Technicians at Allied Auto Works handle emission problems everyday. You might have exhaust or emissions trouble if your car is difficult to start, runs rough, is noisy or smoking. Call Allied Auto Works at 650.968.7227 to schedule an appointment if you experience these problems.

Let's review the exhaust system. We will start from the top and start with the exhaust manifold. That is the part that attaches to the engine and collects the exhaust from the cylinders and directs it into the exhaust pipe. Exhaust gaskets help seal the connection with the manifold and various other joints along the way. If the manifold is cracked or loose, or a gasket is leaking, dangerous gases could escape into the passenger compartment, where you ride. Carbon monoxide can be deadly, so it is important that your exhaust system doesn't leak. The exhaust pipes connect the various components. They can rust or be damaged by a rock, so they need to be inspected periodically.

Next is the catalytic converter. This part looks like a muffler. It changes chemicals that are dangerous to your health and the environment into harmless carbon dioxide and water. It doesn't require any maintenance itself. But eventually they wear out. You will find this out when your car fails an emissions inspection.

Now the muffler. Its main job is to quiet engine noises. Mufflers work by either absorbing or baffling sound. And you can actually customize your car's sound with different mufflers - anything from whisper quiet to bad-boy rumbley. Rusted or road-damaged mufflers can leak and need to be replaced right away.

The exhaust system is attached to the car by a series of hangers and clamps. These fasteners hold the system in place. When hangers come loose or break, hot exhaust components can touch and melt wires, hoses and lines.

Finally, we end at the tailpipe. This is the final outlet for the exhaust. These can be plain-Jane or pretty flashy. Also, the oxygen sensors monitor the oxygen content of the exhaust so the engine control computer can adjust the fuel-to-air mix to keep the car running right.

Exhaust and emissions service covers plain old pipes and high-tech computers. It impacts everything from life and death safety due to exhaust leaks, to fine-tuning the sound of your ride.

Here at AutoNetTV, we have national viewers, like your neighbors in Los Altos, who write to us with questions or feedback. One common question we're asked is: "What is a differential and what does it do?" You may have been told by your Allied Auto Works service specialist that your differential needs service, or seen it as an option up on the service menu. Differential service at Allied Auto Works covers a lot of things, so let's first talk about what a differential does.

As you drive through a turn, your outside wheels and inside wheels turn at different speeds. Kind of like the cars going around a race track - the ones driving in the outside lanes have a greater distance to travel than the cars in the inside lanes. The differential is what allows the outside and inside drive wheels to rotate at slightly different speeds so that the tires don't hop or skip while taking corners, or lose traction in dirt or snow on Los Altos interstates. Differentials have gears in them that transfer the power from the drive train to your wheels - which is why they're often referred to as gear boxes. The gears need to be very strong to do this work, and they need to be properly protected so that they'll last.

All vehicles in Los Altos have some form of differential. If you have a front-wheel drive car, your differential is sometimes called a transaxle and is located in the front. If you have rear-wheel drive, the differential is in the back of the car. If you have a four-wheel drive vehicle, you will have a differential in the front and the back - and in the middle as well. The center differential adjusts for differences in speed between the front and rear wheels.

Differential fluid lubricates and cools the gears. Over time, the fluid can get dirty from bits of the gears grinding off. The additives that keep the fluid clean and protect the differential break down over time. So your auto manufacturer has scheduled intervals for you to have your differential fluid changed.

Differentials are hard working mechanisms, and, along with the gears in a manual transmission, need to be serviced regularly at Allied Auto Works with high-quality, replacement fluid. Your Los Altos service specialist can give you more information as to when your next differential service is recommended. You can also ask if they have a record of when the service was last completed.

As with most service intervals, if you are driving under more severe conditions in the Los Altos area, you will want to service your differential more frequently. "Severe service" conditions are defined in most owners' manuals, and include: frequent starts and stops, short trips, cold CA weather, hot weather and towing. All these factors add to the stress of the vehicle and its parts. Also, off-roading in CA can be especially hard on differentials, especially if you cross streams. Proper service at Allied Auto Works will extend the life of your gears and keep them running more smoothly. If you have never had your differential checked, visit contact-us for more information.

Hey Los Altos! Let's talk about one of our CA summertime must-haves: your car A/C. It's real easy for Los Altos motorists to take their car's air conditioner for granted. Just push the right buttons and out comes cool, dry, clean air. But your air conditioning system needs attention from time to time to help it keep its cool.

Do you hear loud noises under the hood when you turn on your car air conditioner? Do you only get cool air sporadically? If so, it is time to get your air conditioner checked. 

When most Los Altos folks hear the words "air conditioning problems", it sends a shiver up their spine. That is because the air conditioning system is fairly complex. It has a lot of parts and when it's broken, it's costly to repair.

What things can Los Altos and Cupertino motorists do to prevent air conditioning breakdowns?

A common cause of air conditioning failure is leaks. Water and air can leak into the system. It doesn't work as well with air in it and water can cause rust that leads to damage of the car A/C components. Also, refrigerant, the stuff that makes the air cold, can leak out, reducing the efficiency of the system, making it work harder to cool the air. Periodicallyevacuating the air conditioning system and recharging it keeps the proper amount of clean refrigerant in the system so it cools better and lasts longer.

Sunnyvale motorists should run their air conditioner regularly, even during CA winter, so that it lubricates itself and keeps the seals from drying out, which leads to leaks. Your owner's manual will have recommendations for how often to service your air conditioner. Of course, if it's not working right, now is the time to get it checked. Allied Auto Works can inspect and test your air conditioning and offer evacuation and recharge services. This helps you avoid major repairs.

New environmental laws have stopped the manufacture of Freon, a refrigerant that was common in cars made before 1993. There is a very limited supply of Freon so the price is very steep. It may not be worth its weight in gold, but it probably is worth its weight in silver. If you have an older vehicle that uses Freon, you may want to consider having it retrofitted to use the new R134-A refrigerant. It will pay for itself in the long run. So, if your A/C is just a lot of hot air, bring it in to Allied Auto Works for an inspection.

Allied Auto Works
2073 Grant Road
Los Altos, CA 94024
650.968.7227

Most of us living in the Los Altos area are too young to remember life before power steering - cranking those great big steering wheels! It was a pretty good workout. Now power steering is standard. Let's look at how it works. The heart of any power steering system is its pump. The pump pressurizes the power steering fluid that provides assist for steering. Most pumps are driven by a belt that is run by the engine - a few are electrically powered. A high-pressure hose passes fluid from the pump to the steering gear. A low pressure hose returns the fluid back to the pump.

These hoses can develop leaks, so it is a good idea to inspect them at every oil change. Low fluid can damage the power steering pump. That is why fluid level is on the checklist for a full-service oil change. The fluid needs to be compatible with the hoses and seals, so check your owners' manual for the right type - or just ask your personal service advisor at Allied Auto Works.

The fluid cleans, cools and lubricates the power steering system. It breaks down as the years go by and collects unwanted moisture, so Los Altos auto owners need to replace it from time to time. Many car makers specify power steering service intervals. Unfortunately, this important service is sometimes left off the car maintenance schedule for many of us in Los Altos. So, when in doubt, every 25,000 miles/40,000 km or two years is a good fallback. Your Allied Auto Works service advisor will use a detergent to clean the system, flush out the old fluid and replace it with the good stuff.

Here are some warning signs of trouble with your power steering: It's harder to turn the wheel, there's erratic power assist, you hear loud whining coming from the pump (which may be difficult to hear over the loud whining coming from the backseat), you have to top-off the fluid frequently, or you hear squealing belts. Remember to never hold the steering wheel to the far right or left for more than a few seconds at a time. That will wear out your power steering pump real fast.

Other steering components can be bent or damaged from wear or hard knocks. Ball-joint, idler-arm, steering-gear, steering-knuckle and tie rod to name a few. Warning signs here are steering play, wandering, uneven tire wear, and off-center steering wheel. An annual alignment check at Allied Auto Works will reveal bent or damaged steering components.

Most SUV's, pick-ups and rear-wheel-drive cars need regular front-wheel-bearing service.

The bearings should be cleaned and inspected. If they are excessively worn, they need to be replaced. The bearings are then repacked in clean grease. It's also recommend the wheel-seal be replaced when the bearings are serviced. Like everything else, check your owners' manual maintenance schedule. It's usually required around every two years or 40,000 miles/64,000 km. If you drive through water in the Los Altos area, the bearings will need service more often.

Allied Auto Works
2073 Grant Road
Los Altos, CA 94024
650.968.7227