How to Remove and Replace a Crankshaft Pulley

car engine crankshaft pulley
  • 1-6 hours
  • Intermediate
  • 75-450
What You'll Need
Puller
Installer
Hand tools
Lug wrench
Car jack and stands
Vehicle Service Manual
What You'll Need
Puller
Installer
Hand tools
Lug wrench
Car jack and stands
Vehicle Service Manual

Crankshaft pulleys come in a variety of configurations. Some are a simple bolt on being held in place on the crankshaft hub with a few bolts, and there are others that are integral with the front engine crankshaft hub that is also known as a harmonic balancer. The hub will be a press fit on the crankshaft and held in place with a bolt screwed into the end of crankshaft.

This configuration requires the use of some special tools to remove and replace. Attempts to remove and replace the harmonic balancer without these tools will result in damaged components and possible internal engine damage.

Crankshaft pulleys need removed to make it possible to replace the front crankshaft seal (to stop oil leak) and in some engines to gain access to engine timing components.

In some cases the harmonic balancer will need replaced because of the outer ring slipping on the inner hub and causing an imbalance in the engine. These harmonic balancers have a rubber component between the outer ring and the hub that allows some flexing of the outer ring to dampen the effects of the crankshaft rotating harmonics. If this rubber ring has deteriorated, then harmonic balancer replacement is required.

Why Remove Crankshaft Pulley

The crankshaft pulley will need to be removed for a variety of reasons: to replace a worn or damaged pulley, to gain access to the crankshaft front seal, to enable removal of timing cover on many vehicles, to replace a corroded and leaking timing cover, and any type of engine repairs that require access to internal front engine components such as timing chain and sprockets replacement.

Crankshaft pulley removal and replacement is a fairly common vehicle repair procedure and it is explained in the following paragraphs.

Pulley Removal in Front Wheel Drive Vehicles

Be sure to follow safety rules and personal injury protection guidelines when replacing a crankshaft pulley. Safety goggles, jack-stands (when needed), and a common sense approach to the task are good things to do.

Front wheel drive vehicles with the engine installed transversely (crosswise) will require removal of the right front wheel and inner fender liner to gain access to the crankshaft pulley. Raise vehicle with a suitable jack. Safely support the vehicle on jack-stands to remove the wheel.

Check the vehicle service manual for proper procedure to loosen the belts. Remove the belts making note of how they are threaded around the various pulleys, tensioners, and idlers for ease in reinstalling.

Determine if the pulley is a bolt-on or will require the use of a puller. If it is a bolt on type the job is simplified. Remove the fastening bolts and the pulley. Install the new pulley and tighten the bolts to the recommended torque specification that is found in the vehicle service manual.

If it is a pulley that is manufactured integral with the harmonic balancer, then the procedure will require the use of a puller. Use a puller that has through bolts to secure it to the harmonic balancer rather than hooks that grip the outer rim of the pulley. This is important as the hooks can cause damage to the pulley.

Most harmonic balancers have threaded holes to accommodate the puller bolts making this an easy choice. Select the proper bolts to connect the puller to the harmonic balancer.

The harmonic balancer is secured to the crankshaft end with a bolt that needs to be removed so the harmonic balancer can be removed from the crankshaft. It is found inside the center hole of the harmonic balancer.

Be sure the puller you use has its center bolt swivel in place to prevent damaging the crankshaft threads. Tighten the center bolt of the puller until the harmonic balancer comes off the end of the crankshaft.

Inspect the balancer for a wear groove where the oil seal rubs against it. If this groove is too deep, the balancer can be salvaged with an inexpensive press-on repair sleeve to renew the sealing surface. The repair sleeves are available from most auto parts stores. The balancer can also be replaced with a new unit from an auto parts retailer.

If your vehicle has experienced any oil leakage around the front seal at end of crankshaft, this would be a good time to replace that seal. Some engines require the cover be removed as the seal is only accessible from the backside of the cover.

Some seals a pressed into the cover from the outside of the engine. These can be removed using a screw in device to pull the seal. A new seal is then installed using the appropriate tools and a light coating of grease applied to the lips of the seal before final installation.

To reinstall the harmonic balancer onto the crankshaft, it is highly recommended you use a balancer installer tool. This is a long bolt that screws into the end of crankshaft and has a nut and washer on it that are screwed against the harmonic balancer and tightened.

Tighten this nut until the harmonic balancer is securely seated in correct position. Take care not to distort the seal as the balancer is installed. Remove the installer bolt and screw in the retaining bolt. Tighten it to the torque specifications found in your vehicle service manual.

Reinstall the belts that were removed at the beginning of this repair. Replace the inner fender liner and put the wheel back on Tighten the wheel lug nuts to the recommended torque specifications.

Remove the jack-stands and lower vehicle to floor.

Working room clearances can be quite cramped and cause great difficulty in performing the tasks necessary to remove and replace the crankshaft pulley on front wheel drive vehicles.

In many applications this will be a hand tool only as the access room is not enough to accommodate power tools.

Removing Crankshaft Pulleys in Rear Wheel Drive Vehicles

Rear wheel drive vehicles with a front to rear engine install will be different in the pulley removal procedure. Here you will encounter a fan shroud, radiator, and other components that block access to the crankshaft pulley.

A vehicle service manual will be worth its cost in guiding you in the correct process to accomplish pulley removal.

Remove the fan shroud, the fan blades, belts, and any other components in the way.

On a few applications the radiator will need removed. This will require draining the coolant and removing radiator hoses, transmission cooler lines (if vehicle has an automatic transmission), and the radiator.

If the vehicle has air conditioning you should place a piece of plywood to protect the air conditioner condenser from accidental damage from slipped wrenches or other contacts.

Check to see what type of pulley is on the vehicle. If a bolt on then you are in luck and it can be changed by removing the fastening bolts, removing the old pulley, replacing with new pulley, and reinstalling the pulley bolts. Tighten them to the torque specifications found in your vehicle service manual.

If you find the pulley is integral with the harmonic balancer you will need a puller to remove it.

Use a puller that has through bolts to secure it to the harmonic balancer rather than hooks that grip the outer rim of the pulley. This is important as the hooks can cause damage to the pulley.

Most harmonic balancers have threaded holes to accommodate the puller bolts making this an easy choice. Select the proper bolts to connect the puller to the harmonic balancer.

The harmonic balancer is secured to the crankshaft end with a bolt that needs to be removed so the harmonic balancer can be removed from the crankshaft. It is found inside the center hole of the harmonic balancer.

Be sure the puller you use has its center bolt swivel in place to prevent damaging the crankshaft threads. Tighten the center bolt of the puller until the harmonic balancer comes off the end of the crankshaft.

Inspect the balancer for a wear groove where the oil seal rubs against it. If this groove is too deep, the balancer can be salvaged with an inexpensive press-on repair sleeve to renew the sealing surface. The repair sleeves are available from most auto parts stores. The balancer can also be replaced with a new unit from an auto parts retailer.

If your vehicle has experienced any oil leakage around the front seal at end of crankshaft, this would be a good time to replace that seal.

To reinstall the harmonic balancer onto the crankshaft, it is highly recommended you use a balancer installer tool. This is a long bolt that screws into the end of crankshaft and has a nut and washer on it that are screwed against the harmonic balancer and tightened.

Using a hammer to beat on the harmonic balancer to reinstall it can cause damage to the balancer, and force the crankshaft back against the thrust bearing causing internal engine damage that can be extremely costly to repair.

Tighten this nut until the harmonic balancer is securely seated in correct position. Take care not to distort the seal as the balancer is installed. Remove the installer bolt and screw in the retaining bolt. Tighten it to the torque specifications found in your vehicle service manual.

Remove the plywood you placed to protect the air conditioner condenser taking care not to cause damage to the condenser.

Reinstall the radiator, fan blades, belts, transmission cooler lines, radiator hoses, fan shroud, and refill radiator with coolant. Any other items disconnected or removed should be restored at this time.

Recent “Innovations”

A few years ago engineers of the major auto makers came up with a new idea for the harmonic balancer. The end of crankshaft is drilled deeply and threaded for retaining bolt near surface of its end. This configuration requires a “special” puller that has a long push rod that goes in the crankshaft hole to provide necessary support for the pulling operation.

The puller itself has a set of jaws to grasp the harmonic balancer. The engineers left out the tapped holes in the balancer that allowed the use of a through bolt puller.

You now have to acquire a new design jaw type puller to be able to pull the harmonic balancer. These are available from multiple sources with widely varying costs and some variation of the design.

If you plan to do this service on certain late model vehicles, you will need this type of puller to do the job safely and correctly without damaging components.

Be sure to read and follow the manufacturer’s instructions for the proper use of this style puller to avert any damages or personal injury.

Summary

Crankshaft pulley removal and replacement can be a fairly simple task, but can also be quite an undertaking. It all depends on the engineering behind the vehicle being serviced. The simple ones require belt removal, unbolt pulley, remove pulley, install replacement pulley, replace bolts and tighten to torque specifications, and reinstall belts.

The difficult ones will require lots of tools, removal of overlying components, pull the old pulley using a puller, reinstall the new pulley using an installer, and putting back all the previously removed components.

Check the specifications for your vehicle to ascertain the difficulty level of the repair before tackling it.

Any Do It Yourself person with some automotive experience can accomplish a crankshaft pulley remove and replace operation by following safety suggestions, and the procedures outlined in this article.

You will need the proper torque specifications for the fasteners you remove and reinstall while doing this project. This is where a vehicle service manual will come in handy.

It makes good sense for a Do It Yourself person to possess the service manual for the vehicle being serviced as they contain a wealth of information. The author highly recommends you have a vehicle service manual for the vehicle you are servicing.

Get the satisfaction of doing it yourself and save some money in the process.