The factory recommended service intervals for maintaining your 1994.5 to 2003 7.3L PSD engine are fairly simple and straight forward with conditions separated by normal and severe (heavy towing or dirty environments) operating conditions. The recommended life span on newer high quality fully synthetic fluids is longer than the factory recommended service intervals, however, we recommend staying with the factory service intervals unless you get your oil analyzed to ensure all is well when going beyond the recommended intervals.
Recommended Service Intervals |
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Normal |
Severe |
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Engine Oil* | 5,000 Miles / 6 Months | 3,000 Miles / 3 Months |
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Oil Filter | 5,000 Miles / 6 Months | 3,000 Miles / 3 Months |
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Fuel Filter | 15,000 Miles | 15,000 Miles | ||||||
Air Filter | 30,000 Miles / 30 months | Change As Needed | ||||||
Engine Coolant** | First Flush at 50,000 Miles /48 Months
Recurring Flush every 30,000 Miles / 36 Months add 8-10 oz of SCA every 15,000 miles |
Recurring Flush every 30,000 Miles / 36 Months
add 8-10 oz of SCA every 15,000 miles |
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Transmission Fluid (Automatic) | 30,000 Miles (E4OD & 4R100) | 30,000 Miles (4R100) / 21,000 Miles (E4OD | ||||||
Transmission Filter (Automatic) | 30,000 Miles | 30,000 Miles (4R100) / 21,000 Miles (E4OD | ||||||
Transmission Fluid (manual) | 60,000 Miles | 60,000 Miles | ||||||
Transfer Case Fluid | 60,000 Miles | 60,000 Miles | ||||||
Differential Fluid | 100,000 Miles / If axle is submerged in water replace Oil immediately | 30,000 Miles / If axle is submerged in water replace Oil immediately |
* Many synthetic oils have life spans longer than the OEM recommended mileage, however, for engines with HEUI injection it is important things remain clean so changing the oil at 5000 miles or less is still preferred. If you choose to go beyond the factory recommendation then you should have your oil sent off for analysis after each oil change that way you can have scientific evidence to guide whatever mileage interval you choose.
** A note on Coolant: The 7.3L calls for VC-5 (or equivalent) Green coolant which has a recommended maximum lifespan of 30,000 miles and requires diesel supplemental coolant additives to maintain the quality of the coolant via its lifespan to prevent cavitation and pitting within the engine. Then a full flush/change is best remove what is called silicate drop out preventing premature wear of cooling components.