Ford 6.9L IDI Diesel Maintenance Guide
1983-1987 Ford 6.9L IDI Diesel Maintenance Schedule, Fluid Capacity, and Parts List
Ford’s 6.9L IDI, found in their 1983-1987 Heavy Duty trucks and vans, are the epitome of “built tough”. These engines can withstand abuse and their simplicity makes them easy to service and maintain by yourself. My maintaining your 6.9 IDI, you can make sure it has the right fluids, filters, and parts necessary to keep it on the road for a long time. Oh yeah, you’ll also save a fortune compared to taking it in to a shop. To help the owners of Ford 6.9L IDI diesel trucks, we put together this comprehensive maintenance guide. In it, we go over 6.9L IDI Diesel maintenance schedule, fluid capacities, and we even give you the part numbers you’ll need and where to find them. If you’re after the best IDI maintenance guide around, look no further. Let’s dive in to it.

6.9L IDI Diesel Maintenance Schedule
How Often Should I Service my 6.9L IDI?
How often you need to service your 6.9 IDI diesel depends on how you use it. If you use your vehicle for towing lighter loads, tow infrequently, or travel mostly highway miles and use it as a commuter, you should follow the normal operating conditions service schedule. On the reverse end, if you tow frequently, tow heavy loads, or are constantly idling and driving in city traffic, we recommend using the severe operating conditions service schedule.
Normal Operating Conditions
Maintenance/Service | Miles | Kilometers |
Change Oil | 5,000 miles | 8,000 km |
Replace Oil Filter | 5,000 miles | 8,000 km |
Change Fuel Filter | 15,000 miles | 24,000 km |
Drain Fuel/Water Separator | 5,000 miles | 8,000 km |
Replace Air Filter | 30,000 miles | 48,000 km |
Flush Cooling System | 30,000 miles or once every two years | 48,000 km or once every two years |
Check Coolant Nitrile Strength | 15,000 miles or once a year | 24,000 km or once a year |
Adjust Drive Belt | 15,000 miles | 24,000 km |
Inspect CDR Valve | 30,000 miles | 48,000 km |
Replace Auto Transmission Fluid | 30,000 miles | 48,000 km |
Change Auto Transmission Filter | 30,000 miles | 48,000 km |
Replace Manual Transmission Fluid | 60,000 miles | 96,000 km |
Drain & Replace Transfer Case Fluid | 60,000 miles | 96,000 km |
Replace Rear Differential Fluid | 100,000 miles | 160,000 km |
Replace Front Differential Fluid | 100,000 miles | 160,000 km |
Severe Operating Conditions
Maintenance/Service | Miles | Kilometers |
Change Oil | 3,000 miles | 4,800 km |
Replace Oil Filter | 3,000 miles | 4,800 km |
Change Fuel Filter | 7,500 miles | 12,000 km |
Drain Fuel/Water Separator | 3,000 miles | 4,800 km |
Replace Air Filter | 30,000 miles | 48,000 km |
Flush Cooling System | 30,000 miles or once every two years | 48,000 km or once every two years |
Check Coolant Nitrile Strength | 15,000 miles or once a year | 24,000 km or once a year |
Adjust Drive Belt | 15,000 miles | 24,000 km |
Inspect CDR Valve | 30,000 miles | 48,000 km |
Replace Auto Transmission Fluid | 30,000 miles | 48,000 km |
Change Auto Transmission Filter | 30,000 miles | 48,000 km |
Replace Manual Transmission Fluid | 60,000 miles | 96,000 km |
Drain & Replace Transfer Case Fluid | 30,000 miles | 48,000 km |
Replace Rear Differential Fluid | 30,000 miles | 48,000 km |
Replace Front Differential Fluid | 30,000 miles | 48,000 km |
Ford 6.9L IDI Diesel Fluid Capacity
Now that you know how often you need to service your 6.9L IDI, you need to find out how much fluid and oil your truck calls for. The chart below tells you how much fluid or oil the different components of your vehicle calls for. Just pay special attention, because slight differences may exist in fluid capacity between model years. You always want to check dipsticks or fluid reservoirs and make sure you have the perfect amount of fluid present. It’s also not a bad idea to have an owner’s manual or diesel supplement handy to double check.
Oil/Fluid | Capacity – Quarts | Capacity – Liters |
Engine Oil /w Filter | 10 Quarts | 9.5 Liters |
Auto Transmission Fluid 3-Speed Auto C-6 4-Speed Auto A0D | See Below 12-13.5 Quarts 12.3 Quarts | See Below 11.4-12.7 Liters 11.6 Liters |
Manual Transmission Fluid T-19 4-Speed Manual ZF 5-Speed Manual | See Below 3.5 Quarts 3.38 Quarts | See Below 3.3 Liters 3.2 Liters |
Transfer Case BorWarner 1345 | 3.25 Quarts | 3.0 Liters |
Coolant | 29-31 Quarts | 27-29.5 Liters |
Front Differential Fluid Dana 44 IFS Dana 50 IFS Dana 60 MonoBeam (F-350) | See Below 1.9 Quarts 2.05 Quarts 2.9 Quarts | See Below 1.7 Liters 1.9 Liters 2.8 Liters |
Rear Differential Fluid Ford/Sterling 10.25 Dana 60 Dana 70 Dana 70 HD | See Below 3.75 Quarts 3.15 Quarts 3.3 Quarts 3.7 Quarts | See Below 3.5 Liters 3.0 Liters 3.1 Liters 3.5 Liters |
Ford 6.9L IDI Diesel Maintenance Parts, Fluid & Oil
Part Type | Part # |
Engine Oil | Normal Conditions (preferred): SAE 15W-40 Motorcraft 15W-40 Shell Rotella 10W-30 T4 Temperatures < 60 Degrees F: SAE 10W-30 Shell Rotella 10W-30 T4 |
Engine Oil Filter | Motorcraft FL-784 |
Fuel Filter | Motorcraft FD-811 |
Engine Air Filter | Motorcraft FA-1057 / Ford E7TZ-9601-A |
Coolant | Motorcraft VC-5 (Green) Motorcraft VC-5 Prediluted Motorcraft VC-5 Concentrate |
SCA/DCA | Motorcraft VC-8 |
Test Strips | Fleetguard Test Strips CC2602A 4-Pack CC2602A 50-Pack CC2602A |
Thermostat | Motorcraft RT-1049 |
Thermostat Housing Gasket | Motorcraft RG-531 |
Radiator Cap | Stant 10229 |
CDR Valve | Ford E3TZ-6A665-A |
Auto Transmission Fluid C6 3-Speed Auto AOD40 4-Speed Auto E40D 4-Speed Auto | All Compatible with Motorcraft Mercon V ATF |
Manual Transmission Fluid | GL-4 80W-90 Gear Oil |
Auto Transmission Filters C6 3-Speed Auto AOD40 4-Speed Auto | See Below Motorcraft FT-52 Motorcraft FT-58 |
Transfer Case Fluid | Motorcraft XL-12 Transfer Case Fluid |
Front Differential Fluid | SAE 80W-90 Gear Oil Motorcraft XY-80W90-QL |
Rear Differential Fluid** Ford/Sterling 10.25 Dana 60 Dana 70 & 70HD | See Below** SAE 75W-140: Motorcraft 75W-140 SAE 80W-90 Gear Oil: Motorcraft 80W-90 SAE 80W-90 Gear Oil: Motorcraft 80W-90 |
Glow Plugs 1983-1986 (Spade) 1986-1987 (Bullet) | See Below Motorcraft ZD1A / Ford E5TZ-12A342-B Motorcraft ZD9 / Ford F2TZ-12A342-A |
Glow Plug Controller | Motorcraft SW5421 DieselRX Glow Plug Controller |
Drivetrain/Steering/Suspension
Recently, i’ve begun to restore a 1984 Ford F-250 with the 6.9L IDI engine that I picked up for $1500. Let me tell you, you’re in for some serious headaches when it comes to finding parts for your IDI if you’re trying to restore it to it’s former glory days. The one company that has played a huge role in helping me is TorqueKing4x4. I searched everywhere for wheel hubs and dust shields. Thankfully, they still carry a ton of these products and even manufacture some in-house. Their customer service is top-notch and they are the pros when it comes to these old trucks. Tell them I sent you!
Learn More about Ford’s 1983-1987 IDI Diesel
Check out some of our other Ford 6.9L IDI Diesel Resources by clicking on one of the links below.