Owners of other GM cars with engines similar to the 3800 Series II 3.8L V6 may also find the guide to be useful.

These other vehicles include the following: Buick Park Avenue Ultra, Olds Eighty-Eight LS, Oldsmobile Eighty Eight LSS, Olds Ninety-Eight, Pontiac Bonneville (SLE, SSE, SSEi), Buick Riviera, Buick Regal (GS, GSX, SLP), Chevy Impala SS, and the Chevrolet Monte Carlo SS.

I am not a professional mechanic. I assume no responsibility for damage to your vehicle, persons, property or pets. If you have any doubts, please consult an ASE certified mechanic. Please proceed with caution at your own risk.

While replacing the Serpentine Belt and the Supercharger Belt, I noticed that a tensioner pulley and an idler pulley didn't spin easily due to their bearings being worn out.

Rather than wait for them to seize and destroy another belt, I decided to replace both of the stubborn pulleys.

The directions below will cover how to access the belts, remove the belts, remove the pulleys, re-install new pulleys, and re-install the belt.

The tools needed include the following: 13mm socket, 15mm socket, 10mm socket, 8mm socket, a long 1/2" drive breaker bar or ratchet and a 3/8" drive ratchet.

The belts that I installed are the Dayco 5060918 Serpentine Drive Belt, and the Dayco 5060665 PolyRib Supercharger Belt.

Please verify the correct replacement parts for your car by using the Amazon Part Finder website. The correct part numbers may vary depending on the model year, trim level, engine type and whether it has A/C (air conditioning) or not.

I also covered the battery terminals with tape to prevent the possibility of an electrical shock.

If you have a naturally aspirated GM 3800 Series II engine (L36), skip down past the next block of text.

The supercharger tensioner pulley is located near the front of the car right behind a black 3" grooved idler pulley.

Then push the wrench towards the front of the car to relieve the tension on the belt.

With the tension relieved, slip the supercharger belt off the supercharger pulley.

Then you can pull the supercharger belt off the two idlers and the crank shaft pulley.

The serpentine belt tensioner is located right below the alternator.

To relieve the tension on the serpentine belt, push the long handled wrench towards the rear of the car and then pull the serpentine belt off the alternator.

My car has a very slow leak that requires topping off the fluid every 6 months to prevent the PS from whining.

To remove the pulley, place the 15mm socket and long handled wrench on the pulley's bolt.

The pulley's bolt is reverse threaded so to the left is tighten and to the right is loosen.

The 3" smooth tensioner pulley itself can be removed by gently rocking it while pulling it away from the engine.

Clean the tensioner pulley's mount with some compressed air and then install the new pulley.

Remember that the bolt is reverse threaded (A.K.A. "left hand threaded).

Torque it down to about 50 Nm or 37 lb ft with a torque wrench. I tightened the bolt snugly and then turned the wrench another 1/8 to 1/4 turn.

To remove the 3.5" SC idler pulley, place the 15mm socket and long handled wrench on the pulley's bolt.

The SC idler pulley is threaded normally so the "lefty loosy and righty tighty" rule applies.

After loosening the 15mm bolt all the way, the bolt will come off with a large metal washer attached.

To completely remove the pulley, gently rock it back and forth until it slips off the mount.

They come with a 1 year guarantee so make sure you save your receipt in case they seize up prematurely.

Then I threaded the bolt and large washer on a few turns by hand.

If you have a torque wrench the bolt should be tightented to about 50Nm or 37 lb-ft of torque..

Alternatively, you can tighten it snugly and then go another 1/8 to 1/4 of a turn.

The Dayco 5060918 serpentine or "accessory" belt goes on first.

Keep in mind that the flat side of the belt goes around smooth pulleys and the ribbed side of the belt goes against any ribbed pulleys.

The crank shaft is the largest and lowest pulley.

The outer set of ribs on the crank shaft are for the supercharger belt.

Then route the serpentine belt around or over the water pump, air conditioner, power steering and tensioner pulleys.

Hold the serpentine belt near the alternator pulley with one hand.

Then put the 15mm socket and long handled wrench on the tensioner pulley just below the alternator with the other hand.

Push the wrench towards the rear of the car to release the tension on the belt and slip the serpentine belt over the alternator's pulley.

To install the Dayco 5060665 Supercharger belt, first wrap the ribbed side around the outer set of ribs on the crank shaft pulley (lowest and largest).

Remember that smooth pulleys get the smooth side of the belt and ribbed pulleys get the ribbed side of the belt.

Route the supercharger belt over or around the 3" smooth tensioner pulley, the 3" ribbed idler pulley, and the 3.5" smooth idler pulley.

Place the 15mm socket and long handled wrench on the supercharger tensioner pulley (just below the SC pulley and towards the front of the car) with the other hand.

Push the wrench towards the front of car to relieve the tension on the belt.

Slip the SC belt over the SC pulley.

Double check the routing and fit of the belts.

There should only be a tiny amount of slack in each belt.

If either belt feels loose, you may need to replace a belt tensioner mechanism.

For more, check out all of my Pontiac Grand Prix DIY Repair & Maintenance Guides.