How to replace a timing belt
Timing belts play a vital role in keeping your car running smooth. When a timing belt fails, it can be extremely harmful to your engine. And the worst part - it can happen without warning. That's why it's important to replace your timing belt before disaster strikes.
Most timing belts are made to last at least 100,000 km. Check your owner's manual for the car manufacturer's recommendation. If your car is pushing the limit, it's time for a new belt.
Parts you'll need:
- Combination Wrenches
- A Socket Set
- Torque Wrench
- A Harmonic Balancer Puller
- A Three-Jaw Gear Puller
- Timing Light
- Timing Belt Cover Gasket Set
- New Timing Belt
- Drain Pan
- Jack stands
- * Some vehicle models may require special tools
Safety comes first
Every vehicle is different. When it comes to maintenance and repairs, always follow the vehicle's owner's manual.
Safety should be your number one priority. Don't smoke, drink alcoholic beverages, or wear a necktie while working on the car. Watch out for hot objects, sharp instruments, hazardous materials and other potential safety hazards in and around your workspace.
Don't work with a Philips when the job calls for a flat. Substituting tools can compromise your safety or your vehicle's performance.
Never work on a vehicle that is only supported by a jack. Use jack stands to support the vehicle while you work. Work on a solid, level surface. Never jack a car up on dirt or grass.
Finally, when the fun turns to frustration, or if the job requires specialized knowledge beyond your capabilities, please do not attempt it yourself. Talk to a professional mechanic or installer. The last thing we want is someone getting hurt.
Before You Begin
Follow these instructions carefully. Read and be sure you understand them before you begin.
Gather together all of your tools and supplies before you begin.
Allow plenty of time to do the job so you don't have to hurry.
Remember that these are general instructions. For more detailed instructions pertaining to your specific vehicle, consult an appropriate repair manual.
Steps for removing the timing belt
- Disconnect the negative battery cable. Ensure you have your radio security code (if equipped) and record any preset radio stations and the time on a piece of paper to allow for quick resetting once repairs are made.)
- Remove the distributor cap.
- Using a wrench on the crankshaft bolt rotate the engine until the timing mark on the crankshaft pulley is aligned with the 0° mark on the timing scale.
- Verify the distributor rotor is aligned with the index mark on the distributor housing indicating the rotor is in position to fire the number one cylinder. If not, rotate the engine another full turn.
- Remove any components or accessory drive belts that interfere with removing the timing belt cover.
NOTE: This varies by model; consult your service manual to determine which parts need to be removed from your vehicle.
- Check for proper alignment of the crank and camshaft timing marks.
NOTE: Many engines have a dot or index line on the pulleys or sprockets that must be lined up with corresponding marks on the block, cylinder head, or accessory shaft. On some engines, the index mark on the camshaft sprocket aligns with the parting line of the first camshaft-bearing tower. This is very important if you're replacing a timing belt that has broken. Consult your service manual for the correct alignment procedure for your vehicle and correct any misalignment before installing the new timing belt.
CAUTION: Check the area around the belt for signs of oil or other fluid leakage at seals, cam cover and oil pan. Leaks must be repaired before the new belt is installed.
- Loosen the mounting bolt(s) holding the belt tensioner but do not remove it.
- Pry the tensioner away from the belt and then retighten the mounting bolt(s) to hold the tensioner in the loose position.
Examine the tensioner pulley for damage such as dents or cracks.
- Spin the tensioner pulley and listen for a rattle or humming noise that would indicate loose or worn bearings. Uneven wear at the rear of the old timing belt could indicate a misalignment between the tension pulley and timing belt due to worn bearings. If any indications of damage or worn bearings are found, replace the tensioner pulley.
- With the tension on the timing belt relieved, the belt should slide easily off the sprockets. Timing belts that have been used for a long time may stick in the pulley grooves and require some gentle prying with a screwdriver to release.
Steps for timing belt installation
- CAUTION: Do not rotate the crankshaft or camshaft after removing the timing belt unless it's necessary to correct a timing mark misalignment. This could cause engine damage on an "interference" design engine.
- Compare the old and new timing belts. Compare the shape of the belt teeth, the spacing between the teeth, and the width of the belt.
- While the belt is off, check the cam and crankshaft sprockets for wear or damage. Replace them if any damage is found. Slide the new timing belt into position on the sprockets
CAUTION: Do not force a new timing belt over the sprockets. If the belt won't slide easily check to make sure the belt tensioner is fully released. Timing belts are strong in their correctly installed position only. Do not bend or twist them into any configuration other than the correct one.
- Loosen the bolt(s) holding the timing belt tensioner and allow it to contact the belt.
- Proper timing belt tension is essential. Adjust the timing belt to the correct tension, following the procedures for your specific vehicle as outlined in your service manual.
- After the belt tension is properly adjusted, verify the timing marks on the cam, crank, and accessory sprockets are still in alignment.
- With a wrench on the crankshaft pulley, turn the engine over by hand at least two complete revolutions in its normal direction of travel returning to the 0° mark. This will help seat the new belt into place on the sprockets. On "interference" engines, it will also allow you to feel for any hard resistance that may indicate pistons and valves coming into contact.
- Verify the position of all timing marks.
- Reinstall the timing covers and tighten the attaching bolts or screws securely.
- Reinstall the components and drive belts that were removed to gain access to the timing cover.
- Reconnect the negative battery cable.
- Start the engine and verify proper operation.
That's it, you're done. The average time for this job is from three to four hours. Some vehicles will take somewhat longer, especially for a V-6 engine. By doing it yourself, you'll save anywhere from $250 to $400