S197 Ford Mustang Underdrive Pulley Install

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Ford Mustang (S197) Underdrive Pulley install If you have wondered how to get a better throttle response and more bolt-on power from your late-model Ford Mustang, StangNet.com is proud to present this illustrated technical article demonstrating the installation of a set of ROUSH underdrive pulleys. This write-up gives a real-world overview and interpretation on how to install the pulley set on a 2005 Ford Mustang GT. StangNet Staff member bigcat takes us on a journey to getting more power from the legendary pony car. Enjoy!

If you have wondered how to get a better throttle response and more bolt-on power from your late-model Ford Mustang, StangNet.com is proud to present this illustrated technical article demonstrating the installation of a set of ROUSH underdrive pulleys. This write-up gives a real-world overview and interpretation on how to install the pulley set on a 2005 Ford Mustang GT. StangNet Staff member bigcat takes us on a journey to getting more power from the legendary pony car. Enjoy!

Installing S197 Roush Underdrive Pulleys

Tools Needed:

Impact wrench, 18mm, 10mm, 8mm sockets, ratchet, ½” breaker bar or ratchet, screwdriver, harmonic balancer installer OEM # 27144, Chrysler harmonic balancer puller (3 jaw style, not the threaded hole type) OEM # 27139, torque wrench

1. Examine the instructions and become familiar with the procedure before beginning. Make sure you have all the included parts. The Roush set comes with a water pump pulley, a balancer pulley, and a new crank bolt. The included instruction sheet is very easy to follow, with color pictures to help guide you through the installation.

2. Remove the air box assembly. First unclip the MAF Sensor wiring and the PCV line. For the PCV line, push the green tab and pull away. There are 2 bolts holding the air box in place. One is on the throttle body clamp, and the other is behind the air box lid, near the strut tower.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

3. Remove the 8mm nuts holding the radiator overflow reservoir and the power steering reservoir to the fan shroud. Once the nuts are removed, lift straight up to release them from the shroud. Fold them out of the way, into the area that the air box occupied. Draining the fluid from them is not required.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

4. Next, remove the two bolts on either side of the fan shroud, near the top. Unclip the wiring on the passenger side.

5. The shroud needs to be pulled up slightly, as there are two tabs holding it in place near the bottom of the shroud. Once it is raised slightly, you can begin to pull it out of the engine compartment. Watch out for the radiator hoses, as they will catch the lower shroud tabs if you are not careful.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

6. Once the shroud is out of the way, you can begin working on the pulleys. Loosen the water pump bolts, but don’t take them out yet. Belt tension should be enough to hold the pulley as you loosen the bolts, otherwise you will need to hold the pulley as you loosen to prevent it from rotating.

S197 Ford Mustang Underdrive Pulley Install

7. Now that the water pump pulley is loose, make a belt routing diagram. The Roush instructions have this already. Insert a ½” ratchet or breaker bar into the belt tensioner. Push down to relieve the tension. While holding the ratchet down, slide the belt off of one pulley. This will allow you to let off of the tensioner and the belt will hang loosely in place. Remove the water pump pulley.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

8. Begin working on the balancer pulley. Use your Impact to loosen and remove the bolt. Use the 3 jaw puller to remove the balancer. I found that the puller fits best in the rotated to the far left. That is the only place I could get a firm grip to remove the balancer. Remove the balancer and clean off any remaining silicone from the crank snout.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

9. You need to be prepared for this step. Have the installer tool already set up and use the proper adapter. Clean the new balancer well, and then apply a bead of silicone to the keyway. According to the silicone packaging, if more than 4 minutes passes and the balancer is not installed, clean off the silicone and try again. Line up the keyway on the balancer with the crank, and use the tool to press the balancer into place.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

10. After you are finished with the tool, install the supplied NEW crank bolt and tighten the bolt using a torque wrench to 60 lb-ft. This assures that the balancer is properly installed. Next, loosen the bolt, and torque to 37 lb-ft. Once torqued to spec, tighten another half turn.

11. This step varies for different brands of pulleys. Steeda supplies a new bolt, while Roush suggests trimming the stud. If you are trimming the stud, cover the throttle body, the water pump, and anywhere else you don’t want metal shavings to reach. Using a small grinder, rotary tool, or hack saw blade to trim the alternator stud. I trimmed the stud to just before the threads start. Fit the water pump pulley after you trim to be sure you have sufficient clearance. Remember to consider that the belt will add a small amount to the clearance. Clean up the shavings and remove your covers from protected parts.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

12. Once the stud is trimmed for sufficient clearance, install the water pump pulley and bolts. Torque them to 18.5 lb-ft. Reinstall the belt. Don’t forget to loosen the tensioner and follow the belt routing diagram.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

13. Reinstall the fan shroud, using the factory hardware. DO NOT forget to plug in the fans!! Now, you can reinstall the coolant and power steering reservoirs. Don’t forget that they need to be aligned with the slot in the shroud before you install the bolts.

S197 Ford Mustang Underdrive Pulley Install

S197 Ford Mustang Underdrive Pulley Install

14. Reinstall the air box assembly. Remember the MAF sensor wiring and the PCV line.

15. Allow the silicone to thoroughly dry before starting or driving the vehicle to prevent future oil leaks.

Fire it up and see just how quick she revs up!

Categories: Mustang Tech

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