Replacement bearings and pulleys for NSX supercharger kit

How-To: Rebuilding and replacing NSX Comptech supercharger kit pulleys.

 

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How to Rebuild and Replace Comptech Supercharger Pulleys on a Honda NSX

If you’re running a Comptech supercharger kit on your NA1 or NA2 Honda NSX, eventually you’ll run into one common maintenance issue: noisy or worn pulley bearings.

These pulleys spin thousands of times per minute and live in a harsh environment next to the engine. Over time the bearings wear out, start making noise, and can eventually fail.

Fortunately, rebuilding the pulley system is straightforward and inexpensive, and the best part is that the replacement parts are all common off-the-shelf components you can source from your local auto parts store.

In this guide, we’ll walk through:

  1. The pulleys used in the Comptech supercharger kit
  2. Replacement part numbers
  3. How to press out old bearings
  4. How to install new ones properly

The Three Pulleys Used in the Comptech Supercharger System

The Comptech system uses three different pulleys:

  1. Smooth Idler Pulley
  2. Ribbed Idler Pulley
  3. Belt Tensioner Pulley

Two of these can be replaced directly, while one requires pressing in a new bearing.

Replacement Part Numbers

Here are the common replacement parts used when rebuilding the system.

Component Replacement Part Notes
Smooth Idler Pulley DAYCO 89017 Direct replacement (Toyota Corolla application)
Tensioner Pulley NAPA 95274 Direct replacement (Mitsubishi Eclipse application)
Ribbed Idler Bearing TIMKEN 6203-2RS Press-in bearing replacement

These are standard parts stocked by most auto parts stores.

Replacing the Smooth Idler Pulley

The smooth idler pulley is the easiest to replace.

The replacement pulley (Dayco 89017) is nearly identical to the original unit used in the Comptech kit. While the casting may look slightly different, the dimensions match perfectly and it functions the same.

Steps

  1. Remove the old pulley.
  2. Install the new Dayco pulley.
  3. Torque to factory spec.

No bearing pressing or disassembly required.

Rebuilding the Ribbed Idler Pulley

The ribbed idler pulley requires replacing the internal bearing.

This is where most of the work happens.

Step 1: Remove the C-Clip

On the back side of the pulley you’ll find a retaining C-clip.

Remove it before pressing the bearing out with C-clip pliers.

Step 2: Press Out the Old Bearing

Using a shop press, press the bearing out from the opposite side of the C-clip.

Tips:

  • Use a socket that matches the inner diameter
  • Wear safety glasses
  • The bearing will usually release with a noticeable pop

If you don’t have a press, a hammer and drift can work, but a press is strongly recommended.

Step 3: Inspect the Pulley Bore

After removing the bearing:

  1. Inspect the bore
  2. Ensure the surface is smooth
  3. Remove any debris or burrs

The new bearing should sit flush with no resistance.

 


Step 4: Install the New Bearing

The replacement bearing is: Timken 6203-2RS

To make installation easier, use a temperature differential technique.

Option 1 (Best Method)

  • Heat the pulley to ~300°F

  • Freeze the bearing overnight

This expands the pulley and shrinks the bearing, allowing it to drop in easily.

Option 2

Use an induction heater to warm the pulley before installing the bearing.

When properly heated, the bearing should drop into place without pressing.

Step 5: Reinstall the C-Clip

Once the bearing is seated:

  1. Reinstall the retaining C-clip with C-clip pliers
  2. Ensure it is fully seated in its groove

This locks the bearing in place.

Replacing the Belt Tensioner Pulley

The tensioner pulley is another direct replacement.

Replacement part:

NAPA 95274

Simply remove the old pulley and install the new one. No disassembly or bearing work is required.

Final Assembly

Once all components are rebuilt or replaced:

  1. Smooth idler pulley (new)
  2. Ribbed idler pulley (new bearing)
  3. Tensioner pulley (new)

You’re ready to reinstall the pulley system on your Comptech supercharged NSX.

Replacing these wear components will eliminate pulley noise and help ensure reliable supercharger operation.

When Should You Replace These?

Signs your pulleys or bearings need service:

  • Chirping or squealing noises
  • Grinding sounds from the pulley area
  • Visible pulley wobble
  • Rough rotation when spun by hand

If you hear any of these symptoms, it's time to inspect the pulleys.

Need Help?

If you don’t have access to a press or prefer not to do the rebuild yourself, HCE can help.

Reach out and we can assist with:

  • Pulley rebuilds
  • Bearing replacement
  • Comptech supercharger maintenance

Keeping your supercharged NSX running smoothly is what we’re here for.

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