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What kind of transmission fluid does a 2000 7.3 powerstroke take?

The short answer: it uses Mercon V automatic transmission fluid in the 4R100 automatic transmission found on the 1999–2003 7.3L Power Stroke trucks.


In more detail, the 2000 Ford F-250 with the 7.3L Power Stroke is paired with Ford's 4R100 four-speed automatic transmission. Ford specifies Mercon V ATF for this transmission. Using older Mercon fluids or Dexron-based fluids can lead to rough shifting, slipping, or accelerated wear. Always verify with the owner's manual or a Ford service bulletin, especially if the vehicle has been rebuilt or modified.


Transmission background


The 4R100 transmission was used behind the 7.3L Power Stroke in early Super Duty trucks from 1999 through the early 2000s. Understanding this pairing helps ensure you source the correct ATF and follow the proper service guidelines.


Recommended transmission fluid


Below is the primary fluid option that meets Ford’s specification for this setup.



  • Mercon V automatic transmission fluid (ATF) — Ford’s recommended specification for the 4R100 behind the 7.3L Power Stroke in 1999–2003 Super Duty trucks.


Ford’s documentation for this era clearly states Mercon V as the proper ATF. Fluids labeled Mercon or Dexron III alone may not meet the required specification and can cause shifting issues or premature wear in this transmission.


Alternatives and cautions


Some aftermarket fluids claim compatibility with older Mercon specifications, but Ford does not officially sanction them for the 4R100 in this year range. If Mercon V is unavailable, consult a dealer or transmission specialist before substituting fluids.


Maintenance tips


Regular ATF checks, correct level with the engine warm, and changes at intervals recommended by Ford or a trusted mechanic help keep the 4R100 performing well. If you’re performing a fluid change yourself, ensure you have the right fluid grade and proper disposal methods, and consider professional service if you’re not comfortable with transmission work.


Summary: For a 2000 Ford F-250/350 with the 7.3L Power Stroke and the 4R100 automatic transmission, Mercon V ATF is the recommended transmission fluid. Always verify with official Ford sources or a qualified technician, particularly if the vehicle has undergone rebuilds or modifications. Maintaining the correct ATF type and level is essential for smooth shifting and long-term transmission health.

Kevin's Auto

Kevin Bennett

Company Owner

Kevin Bennet is the founder and owner of Kevin's Autos, a leading automotive service provider in Australia. With a deep commitment to customer satisfaction and years of industry expertise, Kevin uses his blog to answer the most common questions posed by his customers. From maintenance tips to troubleshooting advice, Kevin's articles are designed to empower drivers with the knowledge they need to keep their vehicles running smoothly and safely.