Are Timing Belts Directional? Let’s Find Out!

Timing belts are not directional. It’s functional in both directions, so it doesn’t matter in which direction you install it, it is guaranteed that they will work. Also, it won’t cause any performance issues in the engine. However,  proper alignment of the timing belt is mandatory.

So, are timing belts directional? No, but do the directional arrows on the belt matter? Let’s find out.

Are Timing Belts Directional?

A timing belt or timing chain is used in piston engines to synchronise the rotation of the camshaft and crankshaft. Timing belts are entirely symmetrical and don’t have a particular rotational direction. 

So, you can never install a timing belt in the wrong direction as they dont have any direction of installation, But the timing belt must be properly aligned during installation. Because a misaligned timing belt can cause several performance issues.

What are the Effects of A Misaligned Timing Belt?

A misaligned timing belt can cause the following issues:

  1. Engine misfire
  2. Rough idling
  3. Premature belt wear
  4. Reduced fuel efficiency
  5. Reduced engine performance
  6. Engine damage, etc.


Timing belts are not directional. But the timing belt should be aligned properly.

Is It Okay to Reinstall the Same Timing Belt?

If you install your timing belt and discover that you put it in the wrong direction, don’t bother reinstalling them. Because the directional mark on the timing belt doesn’t matter at all.

Timing belts are symmetrical and have no specific rotational axis. So no matter which direction you have installed the belt, it’s guaranteed to work. Check this out if you’re confused about what timing belt you should install on a B20 VTEC.

Moreover, the replacement of a timing belt is a complicated process. It will require you to remove a lot of other components as well. So, it’s better to leave the belt as it is.

However, there are situations when it might be out of alignment and the belt is completely worn out as a result. If that’s the case, you’ll need to purchase a new timing belt and replace it:

How to Install the Timing Belt Properly?

The water pump is located in the belt drive line in many modern engines and new automobile models. Although the water pump may not be faulty, it may malfunction during the new belt’s probable lifetime.

Therefore, it is advisable to change them both at once. Proper engine knowledge is required to repair a timing belt and water pump. We advise leaving it to the professional if you are not used to doing this.

Required Tools to Replace Timing Belt

The following tools are needed to replace the timing belt.

1. Socket wrench set

2. Screw drivers

3. Rubber gloves

4. Timing belt

5. Water pump

6. Coolant

7. Drain pan

8. Ratchet

9. Gasket & Sealant


Before starting with the following procedure make sure to first disconnect the negative battery cable from the battery terminal. This will ensure that there’s no possibility of any electrical accidents.

Step 1: Remove Serpentine Belt 

You need to remove the serpentine belt first. Only then you can move onto the timing belt cover. Because the serpentine belt is mounted on top of the timing belt cover. 

Remove the serpentine tensioner screw using a socket wrench. Then, pull out the serpentine belt slowly. Check if there are any other pulleys on the belt cover. This varies depending on the car model. Remove them as well before you move on to the belt cover.

Step 2: Remove the Timing Cover

The timing cover protects the timing belt and water pump. Use a socket wrench to remove the screws that are holding the timing belt cover. Use a marker to mark these screws and their respective places so it gets easier to put them back.

Step 3: Loose Belt Tension & Remove Old Timing Belt

With the timing belt now accessible you need to loosen its tension first before you can remove it. Use a ratchet on the tensioner pulley and turn it counterclockwise. This will loosen the timing belt. Now slowly remove the timing belt. 

Step 4: Remove Water Pump

The next step is to remove the water pump. First, put a drain pan underneath the water pump. Using a wrench remove the mounting bolts that hold the water pump. You also need to remove the clamps from the hose. This hose circulates coolant through the water pump.

Step 5: Install a New Water Pump & Refill Coolant Reservoir

You need to replace the old gasket before installing the new water pump. Because it gets damaged when the water pump is removed. Scrape out the old gasket using a flat-head screwdriver and replace it with a new one.

Before putting the water pump on, apply an even bead of sealant on the edge. Next, tighten the screws to the manufacturer’s specified torque. Before filling the reservoir tank with fresh coolant don’t forget to reattach the hose.

Step 6:Install New Timing Belt 

Next, you need to install the timing belt with the crankshaft and camshaft. Look for the timing marks on the crankshaft and camshaft and align them accordingly while installing the belt.

Install New Timing Belt 

Source: Expert Help

Ensure the pulley alignment is maintained while doing this. Follow the picture above to clearly understand the placement.

Step 7: Adjust Timing Belt Tension

After installing the timing belt you need to adjust the belt tension. But you need to ensure your car’s specific pulley tension, this varies depending on the different car models.

Rotate the spring-loaded tensioner pulley bolt clockwise to tighten the belt. Keep rotating till the belt is tightened according to the manufacturer’s recommended tension. To check the tension using a tension gauge, you can follow the video below:

Step 8: Re-check the Tension and Coolant Level

Now, reconnect the negative battery cable and run the engine for 5 to 10 minutes with the coolant reservoir cap off. This will eliminate any air in the cooling system. After shutting the engine off, check the coolant level and top it off if necessary.

Also, check the belt tension again. If you find any mismatch in the tension, follow step 7 and adjust accordingly.

Step 9: Reinstall the Belt Cover &  the Serpentine Belt

Now, replace the timing belt cover and other accessories in their respective places. Follow the marks you made in step 2 to put these accessories in their places

Please keep in mind that this is only a guideline. It’s always better to contact a mechanic if there’s any difficulty while doing this.

Tools to Replace Timing Belt Infographic

How Much Will It Cost to Replace the Water Pump and Timing Belt?

The cost of replacing a water pump and timing belt depends on the vehicle’s model. 

Usually, a timing belt kit that includes the belt and the water pump set costs around $50 and $180. If you take it to a garage, you may need to pay an additional $360-$730 as labour charge depending on the car model and the area you live in.

If you need to know whether the BMW 325i comes with a timing belt or a chain, here you’ll find the detailed answers.

When Should You Change the Timing Belt? 

Timing belts should be replaced every 60,000 to 100,000 miles or every 4-6 years on average.


However, the recommended replacement interval may vary depending on the car model. So, make sure you check the owner’s manual to find the exact replacement interval.


How Reliable Are Dayco Timing Belts?

Dayco timing belts are quite reliable. They invented the extra-tiny slot in the tooth apex. This enables more elasticity when a belt is attached to a machine with inadequately designed teeth.

What Effect Does Serpentine Belt Direction Have?

A serpentine belt direction isn’t important at all. The direction of rotation of a new belt has no bearing because all serpentine belts are symmetrical. However, the new belt must be lined properly around the pulleys. The grooved side of the belt must face the pulley grooves for this to work. 

How Long Does It Take A Gates Timing Belt to Wear Out?

Timing belts from Gates are known to last 72 months. Depending on the amount of mileage traveled, some might wear out sooner. But the Gates belts are robust belts with commendable quality and resistance. It is thicker than most OEM belts and heat- and crack-resistant.


That was our take on are timing belts directional. Although these belts are symmetrical and don’t require any particular installation, they must be appropriately aligned. Otherwise, your engine and the entire vehicle may suffer severe damage.

Hopefully, our advice will be useful. But, if installing a timing belt appears difficult, or you are unfamiliar with the subject, keep in mind that this is merely a recommendation. It’s always better to take it to a mechanic in such cases.

Until next time, Good luck!

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Aaron Byrne

Hi, Aaron Byrne here. I'm an expert automotive mechanic with 10 years of experience. I work on engine parts especially timing belts for their repair, maintenance, and replacement.

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Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at with a passion for the automotive industry.