Belts and Hoses Last

Maybe forever, if you rely on an overly liberal interpretation of the maintenance schedules set by some vehicle manufacturers. That doesn’t mean you should ignore them or even accept the manufacturer’s recommendations, though; instead, add them to your list of items that should be checked annually after the first three or so years of ownership.

With accessory drive belts, most manufacturers recommend only a periodic inspection for cracks, fraying or other visible wear, and on some GM vehicles the first inspection isn’t until 10 years or 150,000 miles, when someone else might own the vehicle.

Hoses? What about them? Most owner’s manuals don’t even mention radiator or coolant hoses (except that they can get really hot on an overheated engine). Other hoses, such as for the power steering or air conditioner, usually are mentioned only as something that should be checked as part of routine maintenance or when leaks are suspected.

Coolant hoses typically last several years, though anything longer than 10 years may be pushing the limits. Rubber weakens with age and from repeated exposure to hot coolant, so the older they get the higher chance they’ll leak and cause the engine to overheat.

Drive belts are usually the serpentine type that snake their way around pulleys to power the alternator, air conditioning compressor, power steering pump and perhaps the water pump, and they’re designed to last several years.

When to replace a drive belt is a judgment call by a repair technician, and it’s up to the vehicle owner to decide if the time is right given the manufacturers have largely chosen to stay out of it. We would err on the side of caution, because when a drive belt breaks your car comes to a halt. Depending on where this happens and when, a belt that fits your car may not be available until tomorrow, leaving you stranded.

Comes to automatic transmissions

When it comes to automatic transmissions, fluid leaks and low fluid levels are probably the most common problems owners experience, especially as a vehicle gets older and parts wear out.

If you don’t notice a puddle of transmission fluid (often red, but sometimes other colors or clear) on your garage floor or driveway, you might observe that the transmission is slow to engage a drive gear or shifts sluggishly into higher gears while you’re underway. Both are signs that the transmission fluid is low, which usually can be traced to a leak, though other issues could be at fault. Transmission fluid also can wear out over time and may need to be replaced.

Other warning signs include unusual noises, such as a whine or a buzz, shifting harshly into the next gear instead of engaging smoothly, or slipping out of a gear while driving. If you hear a grinding noise from the transmission, that could be because bearings have failed, allowing metal-to-metal contact between parts that aren’t supposed to rub against each other.

Some vehicles have transmission-warning lights that illuminate when computers sense a problem, but on many cars, the transmission is linked to the same computer that controls the engine, which is the powertrain control module. That could result in the check engine light coming on when you have a transmission issue.

Using your car or truck for towing or hauling heavy loads makes the transmission work harder and can cause it to overheat. Often that will trigger a warning light; if you smell something burning, that could be an overheated transmission. Cars, trucks and SUVs that do a lot of towing or heavy hauling may need what’s called auxiliary transmission fluid cooler.

One Belt That Needs Replacing

All vehicles have an accessory belt that drives features such as the alternator and air-conditioning compressor, and perhaps the power steering and water pump. This belt is usually mounted externally so you can see it on the front end of the engine (the engine is mounted transversely on most front-wheel-drive vehicles), and it usually is a serpentine belt that slithers around various pulleys. It needs to be replaced when it shows wear, such as cracks, fraying or stretching.

Some engines also have a timing belt that is hidden from view but connects the crankshaft on the bottom of the engine to the cylinder head on the top; it controls when valves open and close. Many engines have a timing chain instead of a belt. A key difference is a timing chain is usually considered a lifetime part that doesn’t require periodic replacement. A timing belt does require replacement, though the manufacturer’s maintenance schedule may not call for that until as much as 150,000 miles, as on some current Ford engines.

If either belt breaks, a vehicle is going to soon come to a halt. Once a timing belt breaks, the engine shuts off and you won’t be able to restart it. With many vehicles, you might be able to restart the engine after an accessory drive belt breaks, but you won’t get far if it drives the alternator. Without the alternator, you will be relying on electrical power from the battery, and once that’s gone you will be out of luck.

Though accessory belts can last more than 100,000 miles, they should be inspected by a mechanic periodically (if you know what to look for you can do this yourself). Consult your owner’s manual or service schedule to find out how frequently it should be inspected; this varies by manufacturer. Hyundai says on some current four-cylinders this should be done after six years or 60,000 miles and then every two years or 15,000 miles. Volkswagen calls for it every 40,000 miles, but on some Ford engines it isn’t until 100,000 miles.

Replacement costs also vary, and we’ve seen estimates from less than $75 to more than $150. The best approach is to have it inspected before the recommended interval, and if you decide to have it replaced you will have time to shop around. You may hear warning signals that an accessory belt is on its last legs such as squealing noises when you start the engine or accelerate, or rattling noises from a pulley or tensioner.

Replacing a timing belt is a more involved and costly procedure, typically running from at least $500 to more than $1,000, depending on vehicle. Even worse, on some engines if the timing belt breaks, the pistons may continue to move up and down, and in the process bend valves that have lost their timing mechanism. That can add up to big bucks, possibly $3,000 or more.

That makes timing belt replacement more critical, but because it is not visible you can’t easily check it. That involves removing the accessory drive belts, the engine cover and other hardware just to get a look at it, and no repair shop is going to do this for nothing (they also have to reassemble everything). That is why you should pay close attention to the manufacturer’s recommended replacement schedule. Here, too, recommendations vary. Some Honda V-6 engines call for timing belt replacement at 60,000 miles, for example, but the 1.8-liter four-cylinder used in some Chevrolets lists it at 100,000 miles.

Automatic Transmission Out of Park

Your shift interlock feature, which requires you to step on the brake pedal to prevent unintentionally shifting out of Park, could be malfunctioning. Alternatively, the shift cable or linkage connected to the shift lever could be gummed up with grease or corroded so that it can’t operate freely.

If the interlock switch is worn and not fully releasing, or the brake lights don’t receive a signal from the brake light switch to illuminate, you won’t be able to shift out of Park.

Grease, dirt and moisture can collect in or on the interlock and brake light switches, and on the shift cable and related parts, hampering their operation. When that happens, you’re most likely to have problems shifting out of Park when the engine and transmission are cold, such as after the car has sat for hours. After the engine gets warm — and other parts get warmer, as well — the goo might become softer and make it easier to shift out of Park.

Most cars have a means of overriding the shift lock so you can drive the car to a mechanic rather than have it towed: A small door the size of a fingernail is often found on the console next to or close to the shifter itself. After prying this cover off, one can insert a screwdriver or key and press down to release the lock. Vehicles with column shifters may hide the release on top of the steering column or on the bottom. Your owner’s manual will help you identify the location on your car.

A transmission that’s low on fluid also can be hard to shift out of Park, though that also would likely cause a noticeable degradation in the transmission’s overall performance, such as sluggish or harsh shifts.

Tips for Change the Transmission Fluid

The manufacturer’s maintenance schedule for many automatic transmissions doesn’t call for fresh fluid until 100,000 miles or, with some Ford transmissions, even 150,000 miles. A lot of mechanics say that is too long and it should be done at least every 50,000 miles. Manual transmissions may be on a different schedule, so it’s best to consult the maintenance schedule in the owner’s manual.

Like other vital automotive fluids, transmission fluid deteriorates over time. Hard use — such as frequent stop-and-go city driving, hauling heavy loads, trailer towing — will accelerate the deterioration. That kind of driving raises the operating temperature of the transmission, and heat puts more strain on the transmission and the fluid, which helps facilitate gear shifts, cools the transmission and lubricates moving parts.

If you do a lot of driving under high-stress conditions, you should check the transmission level more often and have a repair shop check the condition of the fluid. Transmission fluid often is red but can come in other colors, and as it deteriorates it tends to turn darker. It may also acquire a burned odor that could indicate it needs to be changed or that the transmission is developing mechanical problems. Another indication it needs changing is dirt or other debris in the fluid. When you take your vehicle in for an oil change or other routine service, the repair facility may urge you to pay for a transmission-fluid change or flush. Even if they can show you that the fluid is darker than original, that might not mean you need fresh fluid right now. Step back, check the maintenance schedule in your owner’s manual and see what the manufacturer recommends before you decide. This also will give you time to price shop.

Many repair shops use flush systems that force out the old fluid and pump in new fluid. Though that sounds good, some manufacturers say you shouldn’t do that (Honda is one; there are others), so you need to know this before you agree to a flush. Look in your owner’s manual. Some manufacturers, such as Honda, also call for their own type of transmission fluid and warn that using other types could cause damage. Moreover, some automatic transmissions have filters that should be cleaned or replaced when the fluid is changed. Make sure the repair facility is using the correct fluid and procedures for your vehicle.