Replacing a timing chain is a major undertaking, but it’s one that can save you a lot of money in the long run. If your timing chain breaks, it can cause serious damage to your engine, and in some cases, it can even total your car. That’s why it’s important to know how to replace a timing chain yourself, so you can avoid these costly repairs.
In this article, we’ll walk you through the steps of how to replace a timing chain. We’ll start with the basics, like what a timing chain is and why it’s important. Then, we’ll get into the actual steps of replacing the chain, including how to remove the old chain and install the new one. Finally, we’ll give you some tips on how to keep your timing chain in good condition, so you can avoid having to replace it again in the future.
Marking the Timing Components
Before removing the timing chain, it’s crucial to mark the timing components to ensure they are reinstalled correctly. This process involves using a paint pen or other suitable marking tool to create alignment marks on the following components:
Camshaft and Crankshaft Gears
Align the camshaft and crankshaft gears with their respective timing marks. Apply a mark to the teeth of the gears that line up with the marks on the timing components.
Timing Chain
Create a mark on the timing chain at the point where it aligns with the timing mark on the crankshaft gear. This mark will help ensure the chain is installed with the correct tension.
Timing Case Cover
Make a mark on the timing case cover that aligns with the timing mark on the crankshaft gear. This mark will serve as a reference point for reinstalling the timing case cover in the correct orientation.
The following table summarizes the marking process for the timing components:
| Component | Mark |
|---|---|
| Camshaft gear | Alignment mark on teeth |
| Crankshaft gear | Alignment mark on teeth |
| Timing chain | Mark at point where it aligns with crankshaft gear |
| Timing case cover | Mark that aligns with timing mark on crankshaft gear |
Removing the Timing Chain
Before you begin removing the timing chain, it is important to take precautions to prevent damage to your engine. Disconnect the negative battery terminal and allow the engine to cool completely. Locate the timing chain cover and remove the bolts that hold it in place. Carefully lift the cover off the engine, being careful not to damage the gasket.
Once the timing chain cover is removed, you will see the timing chain and sprockets. The timing chain is held in place by a tensioner. To release the tension on the chain, locate the tensioner and use a wrench or socket to turn the tensioner bolt clockwise. This will loosen the chain and allow you to remove it from the sprockets.
Removing the Timing Chain from the Camshaft and Crankshaft Sprockets
To remove the timing chain from the camshaft and crankshaft sprockets, follow these steps:
- Camshaft Sprocket: Use a wrench or socket to loosen the camshaft sprocket bolt. Carefully remove the bolt and lift the sprocket off the camshaft. The timing chain will come off the sprocket as you lift it.
- Crankshaft Sprocket: Use a wrench or socket to loosen the crankshaft sprocket bolt. If the bolt is tight, you may need to use a breaker bar or impact wrench. Carefully remove the bolt and lift the sprocket off the crankshaft. The timing chain will come off the sprocket as you lift it.
Once the timing chain is removed from the sprockets, you can proceed to the next step of the replacement process.
Removing the Timing Chain Tensioner
The timing chain tensioner is a spring-loaded device that keeps the timing chain tight. To remove the tensioner, follow these steps:
- Locate the tensioner and use a wrench or socket to loosen the tensioner bolt. The bolt may be located on the side or top of the tensioner.
- Once the bolt is loosened, carefully remove the tensioner from the engine. The tensioner may be held in place by a spring, so be careful not to let it fly out.
- Inspect the tensioner for wear or damage. If the tensioner is damaged, it will need to be replaced.
Installing the New Timing Chain
Once the old timing chain has been removed, it’s time to install the new one. This process is meticulous and requires the utmost precision. Follow these steps to ensure a proper installation:
1. Crank the Engine Manually: Before installing the timing chain, manually crank the engine clockwise a few times to align the crankshaft and camshaft gears. This helps to ensure that the new chain will be correctly positioned.
2. Mark the Gears: Use a permanent marker to mark the alignment of the crankshaft gear, camshaft gear, and intermediate gear. This will serve as a reference point for installing the new chain.
3. Install the Tensioner: Insert the new tensioner into its housing and tighten the bolt to the specified torque. The tensioner’s function is to maintain proper tension on the timing chain.
4. Install the New Timing Chain: Begin by placing the new timing chain over the crankshaft gear. Ensure that the marked links on the chain align with the previously marked positions on the gear. Run the chain upwards and over the intermediate gear, and then downwards and over the camshaft gear. Make sure the marks on the camshaft gear also align with the chain’s marked links.
| Timing Component | Aligned Mark |
|---|---|
| Crankshaft Gear | -“0”-\ Degree Mark |
| Intermediate Gear | Colored Dot or Tooth |
| Camshaft Gear | -“T”-\ Mark |
5. Check the Timing: Once the timing chain has been installed, manually crank the engine again to check the timing. The marks on the gears should still be aligned. If they are not, adjust the chain tension by tightening or loosening the tensioner bolt as needed.
6. Lubricate the Chain: Apply a generous amount of clean engine oil to the timing chain to lubricate it and prevent premature wear.
7. Install the Timing Chain Cover: Reinstall the timing chain cover and tighten all bolts to the specified torque. Top off the engine oil as necessary.
Checking for Timing Accuracy
Once the new timing chain is installed, it’s crucial to verify its accuracy. Here’s how to do it:
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Set the engine to top dead center (TDC): Align the crankshaft timing mark with the reference mark on the engine.
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Remove the spark plug(s): This allows the engine to crank freely without compression.
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Install a timing light: Attach a timing light to the engine’s ignition system and point it at the timing mark.
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Start the engine: Crank the engine and observe the timing mark through the timing light.
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Verify the timing: The timing mark should align perfectly with the reference mark when the engine is running at idle.
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Adjust the distributor (if necessary): If the timing is off, adjust the distributor slightly to align the timing mark. Repeat this process until the timing is accurate.
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Reinstall the spark plug(s): Once the timing is correct, reinstall the spark plug(s) and tighten them to the specified torque.
For vehicles with electronic ignition systems, a scan tool may be required instead of a timing light to check and adjust the timing.
Timing Chain Replacement Costs
The cost of replacing a timing chain varies depending on the vehicle and labor rates in your area. Here’s a general estimate:
| Vehicle | Parts Cost | Labor Cost | Total Cost |
|---|---|---|---|
| Small Car | $100-$200 | $300-$450 | $400-$650 |
| Midsize Car | $150-$250 | $350-$500 | $500-$750 |
| SUV | $200-$300 | $400-$600 | $600-$900 |
Troubleshooting Common Problems
Skipping or Jumping
A skipping or jumping timing chain can be caused by excessive wear or damage. Inspect the chain and sprockets for any signs of damage, such as cracks, nicks, or wear. If the chain is damaged, it will need to be replaced. If the sprockets are damaged, they may need to be repaired or replaced as well.
Slack or Loose Timing Chain
A slack or loose timing chain can cause the engine to run erratically or lose power. Inspect the chain for any slack and adjust it according to the manufacturer’s specifications. If the chain is excessively slack, it may need to be replaced.
Noise
A noisy timing chain can be caused by a variety of factors, including worn or damaged components, improper lubrication, or a loose chain. Inspect the chain, sprockets, and other components for any signs of damage or wear. Also, check the oil level and condition. If the oil is low or dirty, it may need to be changed.
Engine Overheating
An overheating engine can be caused by a variety of factors, including a faulty timing chain. If the timing chain is not functioning properly, it can cause the engine to run hotter than normal. Inspect the chain and other components for any signs of damage or wear. Also, check the coolant level and condition. If the coolant is low or dirty, it may need to be changed.
Reduced Engine Power
Reduced engine power can be caused by a faulty timing chain. If the timing chain is not functioning properly, it can cause the engine to lose power. Inspect the chain and other components for any signs of damage or wear. Also, check the spark plugs and wires.
Poor Fuel Economy
Poor fuel economy can be caused by a variety of factors, including a faulty timing chain. If the timing chain is not functioning properly, it can cause the engine to run less efficiently. Inspect the chain and other components for any signs of damage or wear. Also, check the air filter and the fuel lines.
Difficult Starting
Difficult starting can be caused by a variety of factors, including a faulty timing chain. If the timing chain is not functioning properly, it can cause the engine to be harder to start. Inspect the chain and other components for any signs of damage or wear. Also, check the battery and the starter
Engine Stalling
Engine stalling can be caused by a variety of factors, including a faulty timing chain. If the timing chain is not functioning properly, it can cause the engine to stall. Inspect the chain and other components for any signs of damage or wear. Also, check the fuel system and the ignition system.
How To Replace Timing Chain
Replacing a timing chain is a complex task that requires specialized knowledge and tools. It is generally recommended to have this procedure performed by a qualified mechanic. However, for those who are experienced in automotive repair and have the necessary tools, the following steps can be followed to replace a timing chain:
- Gather the necessary tools and materials, including a new timing chain, a timing chain tensioner, a crankshaft pulley puller, and a camshaft locking tool.
- Safely secure the vehicle using jack stands and wheel chocks.
- Disconnect the negative terminal of the battery.
- Locate the timing chain cover and remove the bolts holding it in place.
- Use the crankshaft pulley puller to remove the crankshaft pulley.
- Use the camshaft locking tool to lock the camshafts in place.
- Remove the old timing chain and install the new timing chain.
- Install the timing chain tensioner and adjust it according to the manufacturer’s specifications.
- Reinstall the crankshaft pulley and camshaft locking tool.
- Double-check the timing marks to ensure they are aligned correctly.
- Reinstall the timing chain cover and tighten the bolts.
- Reconnect the negative terminal of the battery.
- Start the vehicle and check for proper timing.
People Also Ask About How To Replace Timing Chain
What Are The Symptoms Of A Bad Timing Chain?
The most common symptom of a bad timing chain is a rattling noise coming from the engine. Other symptoms can include difficulty starting, rough idling, and reduced engine power.
How Long Does It Take To Replace A Timing Chain?
The time it takes to replace a timing chain can vary depending on the make and model of the vehicle. However, most mechanics estimate that it will take between 6 and 10 hours to complete the job.
How Much Does It Cost To Replace A Timing Chain?
The cost to replace a timing chain can also vary depending on the make and model of the vehicle. However, most mechanics estimate that the cost will be between $500 and $1,500.
