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Steeda Underdrive Pulleys (2001 Cobra; 03-04 Mach 1)

AmericanMuscle no longer carries the Steeda Underdrive Pulleys (2001 Cobra; 03-04 Mach 1). Please check out 1999-2004 Mustang Underdrive Pulleys for an updated selection.

Features & Details

  • SFI Approved
  • 8 - 10 RWHP Recovery
  • Improves Fuel Economy
  • 25% Reduction in Parasitic Accessory Drag
  • Exceeds OEM Material Specifications
  • Fits 2001 Cobra & 2003-2004 Mach 1 Mustangs
Regain Lost Power. Get back the power and torque your belt-driven accessories steal. As hard as it may be to believe, you can regain from 8 to 10 "free" horsepower with Steeda's underdrive pulleys. These pulleys reduce engine parasitic drag from your accessories by about 25% and even improve fuel economy.

Superior Materials. Steeda underdrive pulleys are manufactured from nodular iron, and far exceed the quality of the stock pulleys. The one-piece crankshaft pulley uses a high-tech injection molded bonded rubber damper, making it far more durable than other manufactures "piggyback style" underdrive pulleys.

SFI Approved. Steeda underdrive pulleys are SFI approved for use by all major race sanctioning bodies.

Application. These Steeda Underdrive Pulleys are specifically designed for use on the 2001 SVT Cobra and 2003 to 2004 Mach 1 Mustangs equipped with the DOHC 4.6L V8.

Note: Coupon codes cannot be applied to this product.

Technical note: Midway through the production run for the 2001 model year Ford changed the design of the water pump on the 4.6L engine. The older style pump produced from 1996 to mid 2001 had a longer shaft. In January of 2001 the design of the pump was changed to a shorter shaft. This necessitated a change in the design of the pump pulley.

Fitment: 2001 2003 2004 Details

MPN# 701-0004

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

What's in the Box
  • (1) Crankshaft pulley
  • (1) Water pump pulley
  • (1) Alternator pulley
  • (1) Bolt
Installation Info
Tech Specs
UnderDrive Pulley Specifications
Year/Model: 2001 Cobra
2003-2004 Mach 1
Manufacture: Steeda
Material: Steel Finish: Black
Crank Pulley: One Piece Crank SFI Certifited: Yes
Will it fit my Mustang?

    Customer Photos (3) Submit Your Photo

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      Questions & Answers (6)

      5 Top Rated Questions

      2 questions on the pulleys... 1. Will this require any type of rebalance? In a previous answer about overheating you mentioned a better radiator, but not water pump. Would the radiator or water pump be a better fix for the heating issue?

      • The Steeda Underdrive Pulleys will not require any type of re balance, in the event you experience overheating it should not be caused by the Underdrive Pulleys.

      Helpful (0)

      Will this kit change the size or type of belt/s I need on my 03 Mach 1?

      • The Steeda Underdrive Pulleys is designed to accept the OEM belt.

      Helpful (0)

      I have noticed a few issues of vehicle overheating after installing this product. How common is this and would it be necessary to have the fan come on at a lower temperature due to water pump speed being slowed?

      • With under-drive pulleys it is common to see increased engine temps and heat soak. It is recommended if you start experiencing this to upgrade the cars cooling systems. I would recommend looking into a higher performance radiator and fan to keep the heat down.

      Helpful (0)

      has anyone had any fitment issues with these? I bought them, and my mechanic is telling me they won't clear the radiator fan. I disagree, I haven't heard of any issues. any other Mach 1 owners have fitment issues?

      • We have not seen any issues with fitment of the Steeda Underdrive Pulleys when properly installed.

      Helpful (0)

      Will this fit my 04 Cobra

      • Unfortunately, these Steeda Underdrive Pulleys will not fit a 2004 Cobra.

      Helpful (0)
      Post Your Question
      1 More Question
      Is the Steeda under drive pulley for the 2001 SVT Mustang the exact size as the stock pulley? 1 answer

        Customer Reviews (12) Write a Review

        Overall Rating 4.3

        out of 5 stars

        Installation Time:Afternoon

        • Performance Gain 3.4 3.4
        • Fit 4.6 4.6



        • 2/5

          Installation Time: Afternoon

          January 13, 2019

          Steeda undersrive pulleys

          Was very happy when I received them, and very excited to get them on. But due to being active duty I rarely have the time to do the work on my car. Upon trying to put them on today I ran into a problem after another. The water pump pulley sits too far out for the belt to sit on properly, the alternator pulley did not fit, the only pulley that managed to sit right was the crank pulley. But upon putting it all together my car started acting very weird. Loud squeals starting forming, when it starts the steering becomes hard. After driving 20minutes assuming it just needed to adjust itself, the crank pulley was burning hot, every other pulley was fine. And now my FP Duty cycle is sitting .06-.07 higher than normal. For idle it runs .23-.25 at one point I saw .40 which I’ve never seen. At the moment I am very unhappy with this purchase. I tried calling AM but I sat on a wait for over an hour and still no call.

          JesseK

          Year: 2001 Submodel: Cobra

          Helpful (3)

        • 5/5

          Installation Time: Less than 1 Hour

          July 30, 2018

          Smoother Ride

          These pullies made my car run much smoother since I changed out the harmonic balancer, better throttle response, noticble power gains. Real easy to install with the proper tools.

          ArmandoV

          Year: 2001 Submodel: Cobra

          Helpful (5)

        • 5/5

          Installation Time: Less than 1 Hour

          March 26, 2018

          Great Product!

          The Steeda pulleys are excellent quality and easy to install. They also make a noticeable difference while driving.

          MarkD

          Year: 2003 Submodel: Mach 1

          Helpful (6)

        • 4/5

          Installation Time: Less than 1 Hour

          June 16, 2017

          Smoother

          Before you buy this product make sure you understand what these do. I've read about other people getting overheating problems from them. The reason being if you have anything on the edge about to go with your coolant system this will most likely push it over the edge (as in my water pump and that was a headache.) I love how much smoother the mustang drives. I recommend getting the ARP bolt and washer that AM offers to go with them. These are good quality pulleys.

          TimothyN

          Year: 2003 Submodel: Mach 1

          Helpful (9)

        • 3/5

          Installation Time: Less than 1 Hour

          April 02, 2017

          Steeda Underdrive Pulleys

          These pullies were extremely easy to put on with a simple impact gun for the alternator pulley, a ratchet for the water pump pulley, and a torque wrench for the crank pulley. Saw some good gains and the car did run smoother. HOWEVER, my car kept overheating with these pulleys. I don't know if it was the car being old and needing a new water pump, new radiator, or what but for me these pullies require supporting mods to run effectively

          BrandonB

          Year: 2001 Submodel: Cobra

          Helpful (7)

        • 5/5

          Installation Time: Less than 1 Hour

          June 10, 2016

          Best bang for the buck

          It took me 30minutes to install these pulleys on my Mach 1..it helped me because I didn't have to install alternator pulley..but make sure you put car in 5 gear when doing crank pulley and loosen all bolts before you take belt off made it easier to loosen crank pulley without spinning crank. After done quick upgrade for quick response in gas pedal.

          MachU

          Year: 2004 Submodel: Mach 1

          Helpful (9)

        • 5/5

          Installation Time: Afternoon

          June 18, 2013

          Pretty good

          Easy to install, nice product, I didn't see a big improvement in performance, but it does make the car run smoother, my engine vibrates way less all the way to the tranny, I can feel it thru the shifter. All and all a pretty good product worth buying.

          Albepilot

          Year: 2003 Submodel: Mach 1 Riverside, CA, USA

          Helpful (8)

        • 3/5

          Installation Time: Afternoon

          February 15, 2013

          Not recommend. Too expensive for a money.

          Well you can fell something but... you'd better save some money for a supercharger or turbo kit Fitting quite easy but I had to crush my old alternator pulley teeth to dismantle it. I not recommend it. It's too expensive for a money.

          AdrianPoland

          Year: 2001 Submodel: Cobra Poland

          Helpful (10)

        • 5/5

          Installation Time: Afternoon

          August 26, 2012

          Great set!

          Great price, easy install, quick way to gain some lost power back and it's Steeda so u know its quality!

          grandtheft501

          Year: 2003 Submodel: Mach 1

          Helpful (6)

        • 5/5

          Installation Time: Afternoon

          March 23, 2012

          STEEDA U/D PULLEYS

          When you buy this, I mean c'mon.. It's Steeda! Installed it on the Naval base I'm stationed at using the auto hobby shop. Very easy to install, but definitely had to pay close attention to the bolt installation and torque limits. Once installed it felt like my accessories were running lighter, but not much of a gain in HP, probably maybe 1 or 2 HP that's about it, but then again, I don't have a Super Charger to actually feel the difference. But still a good product to have!

          DROCK79

          Year: 2004 Submodel: Mach 1 Marrero, LA

          Helpful (9)

        • 5/5

          July 15, 2011

          amazing as always

          another great product from steeda easy install great gain in performance..a must have!!!!!

          ryan

          Year: 2004 Submodel: Mach 1

          Helpful (6)

        • 5/5

          June 04, 2011

          Great value mod for my 2001 Cobra

          I have a 2001 Cobra and it's a little hard to find parts for. These pulleys for a great value find. Low price compared to others, easy install too, it took 1 hour labor from my mechanic. I recommend these from Steeda!

          Jason Wells

          Year: 2001 Submodel: Cobra

          Helpful (7)

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