Timing Belt Kit Buyer’s Guide
- The timing belt is the large black rubber band that’s often seen at the side or at the front-end of the engine, depending on the engine layout.
- Timing belts are made of synthetic rubber with teeth on the inside surface, which grip the camshaft and crankshaft pulleys.
- The timing belt ensures that the camshaft and crankshaft are turning at the correct and optimal rate.
- A timing belt consists of an outer rubber, main rubber, tension cords, and teeth coating.
- Symptoms of a failing timing belt include rough idling behavior, engine misfire, heavy smoke coming out of the engine, untimely wearing of the pistons or valves, and a strange ticking noise from the engine.
- Manufacturers typically advise to replace timing belts between 60,000 and 100,000 miles.
- OE replacement timing belt kits on CarParts.com cost between $4 and $450.
- For high-quality replacement timing belt kits, shop via CarParts.com. Have a vast selection of OE replacement parts only from the reputable brands.
Your car is a combination of hundreds of parts working together so you could go from point A to point B. The power comes from the engine which travels from the transmission to the driveshaft, then onto the axles, which makes the wheels spin. However, that’s just a roughly simplified explanation of everything that’s happening inside your car.
The engine alone needs more internal parts than you probably are aware of, such as the crankshaft and camshaft. These components help create and deliver the power from the pistons to the various components of your vehicle through the timing belt.
What is a timing belt?
The timing belt is the large black rubber band that’s often seen at the side or at the front-end of the engine, depending on the engine layout. Timing belts are made of synthetic rubber with teeth on the inside surface, which grip the camshaft and crankshaft pulleys. Without these teeth, the belt would slide and affect the synchronization of the system.
The main purpose of the timing belt is to synchronize the movements of both the crankshaft and camshaft, or else you’ll end up with damaged valves, pistons, and other surrounding parts. The timing belt ensures that the camshaft and crankshaft are turning at the correct and optimal rate. It does this by allowing the valves to open at the perfect timing relative to each cylinder’s intake and exhaust strokes.
Anatomy of a timing belt
If you think timing belts are simply made of molten and molded synthetic rubber, you are mistaken. The timing belt is a crucial part of your combustion engine, which is why it needs to be as rigid as possible. To understand the timing belt better, let’s take a closer look at it’s structure and identify its parts.
The outer rubber is the exposed surface of the timing belt that’s in contact with the tensioners. The purpose of the outer rubber is to protect the tension cords buried deep in the core of the belt. There are three common materials used in making the outer rubber, namely Chloroprene Rubber (CR), Chlorosulfonated Polyethylene Synthetic (CSM), and Hydrogenated Nitrile Butadiene Rubber (HNBR).
The tension cord is what makes the timing belt rigid. It serves as the skeletal system of the timing belt. Since the timing belt loops around pulleys, the skeleton needs to be flexible, apart from being rigid. Timing belt suppliers achieve this by using fiberglass in making the tension cord.
The inner layer of the timing belt that’s past the tension cords is also made of the same materials as the outer rubber, which are CR, CSM, and HNBR. This side of the belt is specifically molded to have precise grooves, known as teeth.
The crankshaft and camshaft rotates at high rates of speed. At this speed, the rubber teeth could easily get damaged and may result in loss of grip. Good thing there’s a nylon coating that is applied on the inner side of the timing belt. The nylon material helps maintain the shape of the timing belt’s teeth.
Symptoms of a failing timing belt
Have you ever wondered about when to replace a timing belt? Manufacturers typically advise to replace timing belts between 60,000 and 100,000 miles. If you want to be very sure, you may refer to the vehicle owner’s manual. Manufacturers also recommend that you follow your service interval to make sure the timing belt is in good condition. If you’re in doubt about its condition, here are the symptoms of a failing timing belt.
Rough idling behavior
The teeth of the timing belt is covered with a nylon coating to make it durable. If you fail to check on your timing belt after the specified mileage, you could face deterioration on the inner side of the timing belt. Once the teeth begin to fall off or get brittled, your timing belt wouldn’t be as efficient as before. It would tend to slide as the pulleys rotate and worse is that teeth could get stuck on the gears.
If these happen, your engine might begin to shake wildly, especially when you’re idling. If this symptom persists without bringing it to a certified mechanic, it could lead to more problems like a stalling engine due to the camshaft’s poor timing.
Having a bad timing belt also compromises the fire rate of your engine as one or two of the cylinders could open or close too soon. Poor cylinder timing is a perfect recipe for an engine misfire. If you don’t replace a bad timing belt that’s causing this issue, you could face a permanent engine damage.
Heavy smoke from your engine
You should take note that on top of every cylinder are two holes that lets out exhaust and allow fresh air in. The opening and closing of these holes are synchronized with the cylinder’s movement, as well as the camshaft’s rotation. A slight change in timing caused by a slipping timing belt will jeopardize the process, which causes more smoke coming out of the exhaust system.
Untimely wearing of pistons or valves
A worn timing belt could snap at any moment, leaving your crankshaft and camshaft unsynchronized completely. The worst-case scenario is pistons that come in contact with the valve as they open. This could damage either the piston and valve—even worse, both. If you notice something unusual with how your car runs, immediately shut the engine off or take it to the nearest repair shop for a certified mechanic to examine.
Strange ticking noise from the engine
There could be various sources of a ticking sound as a sign of a failing timing belt. A bad timing belt could easily slip on the pulley which affect the synchronization of the crankshaft and camshaft. If the problem worsens inside the engine, you could end up hearing sounds coming from the unusual behavior of moving parts. Any unusual sound coming from the engine is an indication of a problem that shouldn’t be ignored. So the moment you start hearing a ticking, clunking, squeaking sound, seek a professional’s help.
Benefits of replacing a timing belt
Replacing a worn timing belt does not only ensure proper camshaft and crankshaft synchronization. It also saves you money by preventing even more problems along the way. Keep in mind that your car is at its best if all the moving parts inside and outside the engine are working in unison. You’re also avoiding the risk of any accidents that could happen if your engine fails on the highway.
For high-quality replacement timing belt kits, shop via CarParts.com. Have a vast selection of OE replacement parts only from the reputable brands.
What to Consider When Choosing a Timing Belt Kit
If you’re in the market for a timing belt, you could either opt to purchase a timing belt. However, you could also choose to replace neighboring components like the tensioner pulleys, water pump, and camshaft and crankshaft seals, and idler pulley. The timing belt repair cost would definitely be more expensive in the long run than replacing what needs to be replaced. In that case, what you need is a timing belt kit.
Timing belt kit vs. Timing belt
When it comes to timing belt replacement, it is recommended that you purchase a complete timing belt kit because it will make installation easier for you, especially if you're planning on doing the repair yourself. Replacing all the parts simultaneously also means they'll wear out evenly.
If you install a new timing belt and your water pump is already worn out, coolant may leak on the new rubber and affect the belt's performance. If you'll only purchase the timing belt, chances are you'll discover that some parts also need replacing. Purchasing a complete timing kit will save you additional trips to the local parts store, and it will also save you money in the long run.
How much does a timing belt cost?
The OE replacement timing belt price varies between $4 and $450. They can be sold with or without a water pump replacement. Timing belt kits varies depending on the part inclusion. Some timing belt kits include a full set of tensioner pulleys, crankshaft and camshaft pulleys, water pump, and idler pulleys.
How to Install a Timing Belt Kit
Timing belts need to be replaced approximately every 60,000 miles. Difficulty in starting the engine, rough idling, backfiring, excessive vibrations, and squealing sounds are signs of timing belt failure. A worn timing belt will also present signs of cracking and fraying, so you need to have it replaced as soon as possible. Below are the tools you'll need and the steps to follow when replacing the timing belt:
Difficulty level: Moderate
Tools that you'll need:
- Combination wrenches
- Socket set
- Three-jaw gear puller
- Jack stands
- Torque wrench
- Drain pan
Step 1: For your safety, jack up your car and use jack stands to ensure it is well supported during the removal and replacement process.
Step 2: Disconnect the battery cable and remove the distributor cap. Check if the transmission is in neutral.
Step 3: Rotate the engine to top dead center (TDC). This is marked by an "o" on the timing scale. Use a wrench on the crankshaft bolt to do this.
Step 4: Remove the spark plugs and all plastic shields underneath your engine.
Step 5: Remove the radiator, engine drive belts, cap and rotor, and the water pump pulley.
Step 6: Remove the bolts and screws on the timing cover and lift it off the engine.
Step 7: Check if the crank and camshaft timing marks are properly aligned. Check also the area surrounding the belt if there are signs of leakage. Ensure there are no leaks before installing the new timing belt.
Step 8: Release the timing belt tensioner and its mounting bolts a bit but do not remove them completely.
Step 9: After loosening the tensioner, slide off the old timing belt.
Step 10: Check again if the engine is at TDC for easier confirmation of timing marks.
Step 11: Slide in the new timing belt and adjust it to the correct tension.
Step 12: Verify if the timing marks on the accessory sprockets, cam, and crank are still in correct alignment.
Step 13: Reinstall the timing cover and all the components that were removed upon installation. Tighten all bolts and screws.
Step 14: Reconnect the battery cable and start the engine to check the operation of your new timing belt.
Timing belt installation takes around three to four hours. It might take a little longer for a beginner.