Tech Articles / How-To's: Installing Mac underdrive pulleys

Disclaimer: The articles below apply to most 5.0 Mustangs, but in particular hold true for '93 models. Please be cautious when doing on work on your car - these instructions are meant to be pointers and not the end all truth - I do not make any claims to their accuracy and will not be held responsible for anything that may go wrong while following the articles below. If you choose to follow these instructions, you do so at your own risk.

  1. Disconnect battery cable - remember to remove negative cable first
  2. Unbolt fan shroud
  3. Unbolt fan from water pump, making sure not to lose any of the washers
  4. Lift out fan/shroad assembly
  5. Remove stock water pump pulley
  6. Remove four bolts from inside of crank shaft pulley
  7. Remove stock crank pulley - may need to tap it to loosen
  8. Unbolt alternator
  9. Unhook both cables on alternator
  10. Using impact wrench, remove stock pulley from alternator (if you do not have one, most AutoZones will swap the pulley for free if you bring in new pulley and your alternator)
  11. Remove any spacers behind stock pulley
  12. Install new pulley and attach with washer and bolt using an impact wrench
  13. Rebolt alternator into place, remembering to reconnect cables
  14. Bolt on new crank shaft pulley
  15. Place new water pump pulley on
  16. Lower fan shroud/fan assembly back into place
  17. Reconnect fan to new water pump pulley
  18. Route the serpentine belt into place, noting proper direction often noted on stick on front bumper
  19. Make sure everything lines up properly
  20. Reconnect battery cable
  21. Start car momentarilly
  22. Immediately check belt to see if it remained on path
  23. Run car again, watching all of your gauges and check belt

*Note: You should be able to use stock cable with these pulleys. As with all underdrive pulleys, your voltage gauge will read lower. However, if it goes into the red, something is wrong. Also, cooling may be reduced. I have a high flow water pump, so no issues have occured with cooling to date.

**Note: After having the pulleys on for several months, I removed the alternator pulley and replaced it with the stock one, as my aging charging system was beginning to have issues. This required a slight change in belt size.


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