90K Service

Comprehensive 90,000-mile maintenance service including all fluid changes, filter replacements, and inspection of key drivetrain and chassis components for the 5.9L Cummins diesel 4WD Ram 2500.

Warnings

Tools required

Parts

• Engine oil filter × 1 — Fleetguard LF3977 or equivalent
• Fuel filter/water separator × 1 — Fleetguard FS19532 or equivalent
• Fuel filter secondary (if equipped) × 1 — Fleetguard FS19516 or equivalent
• Air filter × 1 — Mopar 5086360AA or equivalent
• Automatic transmission filter and gasket kit × 1 — Mopar 68003756AA or equivalent
• Transfer case filter and gasket (if equipped) × 1 — Use OEM specification
• Differential cover gasket - front × 1 — Use RTV sealant or OEM gasket
• Differential cover gasket - rear × 1 — Use RTV sealant or OEM gasket
• Drain plug washers/gaskets (assorted) × 6 — Use OEM specification

Fluids

• 15W-40 diesel engine oil — 12 qt
• Mopar ATF+4 — 18.5 qt
• 75W-90 synthetic gear oil — 9 qt
• Ethylene glycol 50/50 coolant — 28 qt
• DOT 3 brake fluid — 1 qt
• Windshield washer fluid — 4 qt

Preparation

1. Park vehicle on level surface and allow engine to cool completely for at least 1 hour
2. Engage parking brake and place wheel chocks behind rear wheels
3. Gather all fluids, filters, and tools before beginning work
4. Verify you have correct fluid types and quantities for your specific model year
5. Prepare adequate drain containers and waste fluid storage
6. If performing coolant flush, ensure engine is completely cold before opening system

Procedure

1. 1

   Engine oil and filter change
   Raise vehicle and support securely on jack stands. Locate oil drain plug on bottom of oil pan. Place drain pan underneath and remove drain plug, allowing oil to drain completely (approximately 10-15 minutes). Remove oil filter using filter wrench. Fleetguard LF3894/LF3970/LF3977 — verify correct number for your engine (12-valve vs 24-valve) against Fleetguard catalog. Clean filter mounting surface, apply thin film of clean oil to new filter gasket, and install new filter hand-tight, then tighten an additional 3/4 to 1 turn per the instructions printed on the filter. Install drain plug with new washer. Lower vehicle and fill with approximately 11 quarts of 15W-40 diesel engine oil, then verify final level with the dipstick. Start engine and check for leaks, then shut off and recheck oil level after 5 minutes.
2. 2

   Fuel filter replacement
   Locate fuel filter/water separator assembly on driver side frame rail. Place drain pan underneath. Open water drain valve at bottom of fuel filter housing to relieve any pressure and drain water. Close drain valve. Use fuel filter wrench to remove filter canister by turning counterclockwise. Clean mounting surface thoroughly. Fill new filter approximately 3/4 full with clean diesel fuel to aid priming. Lubricate gasket with diesel fuel and install new filter hand-tight. If equipped with secondary fuel filter (mounted on engine), repeat process. Verify exact Fleetguard part number for your model year and injection system (VE, VP44, or common rail) against Fleetguard catalog for the fuel filter/water separator. For secondary fuel filter, if equipped, verify exact Fleetguard part number for your model year against manufacturer catalog. Prime fuel system using the hand primer pump or key-on cycles until the primer becomes firm and fuel flow is established with no air. Start engine and check for leaks, allowing to idle for several minutes to purge air.
3. 3

   Air filter replacement
   Open hood and locate air filter housing on driver side of engine bay. Release clips or remove fasteners securing air box cover. Remove old air filter and inspect housing for debris or dirt. Clean housing interior with shop towel if necessary. Install new air filter ensuring proper seating in housing. Air filter — verify correct Mopar/Fleetguard part number for your model year against manufacturer catalog. Reinstall air box cover and secure all clips or fasteners. Inspect all air intake ducting for cracks or loose connections.
4. 4

   Automatic transmission service
   With vehicle raised and supported, locate transmission pan underneath vehicle. Position large drain pan underneath transmission pan. Remove all pan bolts except two at corners, loosening remaining bolts gradually to allow pan to tilt and drain. Once drained, remove final bolts and lower pan carefully. Remove old filter by pulling straight down from valve body. Clean pan thoroughly, removing all old gasket material and metal debris from magnet. Install new filter, ensuring O-ring or seal is properly seated. Transmission filter and gasket kit — verify correct Mopar part number for your specific transmission (e.g., 47RE/48RE) against manufacturer catalog. Install new pan gasket and reinstall pan, tightening bolts in crisscross pattern. Using fluid transfer pump, add approximately 4-5 quarts of ATF+4 (backward-compatible; supersedes ATF+3 used on 1994-1997 models) through dipstick tube. Start engine, shift through all gears, then check level with engine running in park on level ground. Add fluid as needed to reach proper level on hot range (total capacity 14 quarts, but only 4-5 quarts replaced with pan service).
5. 5

   Transfer case service
   Locate transfer case on passenger side of transmission. Clean area around drain and fill plugs. Remove fill plug first to ensure it can be removed. Place drain pan underneath and remove drain plug, allowing fluid to drain completely. If equipped, remove filter access cover and replace filter with new unit and gasket. Reinstall drain plug with new washer. Using fluid transfer pump, fill transfer case with approximately 2 quarts of Mopar ATF+4 through fill hole until fluid reaches the bottom of the fill hole (verify exact capacity for your transfer case model). Install fill plug with new washer and tighten securely.
6. 6

   Front differential service
   Locate front differential housing. Clean area around fill and drain plugs. Remove fill plug first using appropriate socket. Place drain pan underneath and remove drain plug at bottom of housing. Allow gear oil to drain completely. Inspect drained oil for metal particles or water contamination. If differential has a cover instead of drain plug, remove cover bolts and carefully pry cover off. Clean cover and housing mating surfaces thoroughly, removing all old gasket material. Apply RTV sealant or install new gasket. Reinstall cover or drain plug with new washer. Using fluid transfer pump, fill with approximately 2.5-3 quarts of 75W-90 gear oil (verify exact capacity for your front axle) through fill hole until oil level reaches bottom of fill hole. Install fill plug with new washer.
7. 7

   Rear differential service
   Locate rear differential cover on rear axle. Clean area around cover bolts. Loosen fill plug first to verify it can be removed. Remove all cover bolts gradually, allowing gear oil to drain into pan. Once drained, remove cover completely. Clean cover and housing mating surfaces thoroughly. Inspect ring and pinion gears for unusual wear patterns. Clean magnet in cover of metal particles. Apply RTV sealant bead or install new gasket to cover. Reinstall cover, tightening bolts in crisscross pattern. Using fluid transfer pump, fill with the correct quantity of 75W-90 gear oil for your rear axle (typically ~3.5-4 quarts for Dana 80; verify exact capacity, and add limited-slip friction modifier if equipped) until level reaches bottom of fill hole. Install and tighten fill plug.
8. 8

   Coolant system service
   Ensure engine is completely cold. Place large drain pan under radiator. Open radiator drain petcock at bottom driver side of radiator or remove lower radiator hose. Open radiator cap slowly to vent system and allow coolant to drain. Drain coolant from engine block by removing block drain plugs if equipped (typically on both sides of block). Once drained, close all drain points. Fill system with clean water, start engine and run until thermostat opens, then drain again. Repeat flush until water runs clear. Close all drains. Mix fresh coolant 50/50 with distilled water (or use pre-mixed). Fill radiator completely, then fill overflow reservoir to cold fill line. Start engine with radiator cap off, allowing engine to warm up while monitoring coolant level. Add coolant as level drops from air purging. Once thermostat opens and coolant circulates, top off radiator and install cap. Check overflow reservoir level when cold and adjust to proper mark. Test coolant strength with hydrometer (should protect to -34°F minimum).
9. 9

   Brake fluid exchange
   Locate brake fluid reservoir under hood. Using turkey baster or fluid pump, remove old brake fluid from reservoir. Refill with fresh brake fluid meeting the specification stamped on the master cylinder reservoir cap (typically DOT 3). Have assistant pump brake pedal several times and hold pressure. Starting with the wheel furthest from the master cylinder, open bleeder valve slightly until old fluid begins to flow into catch container, then close valve before pedal reaches floor. Follow the bleed sequence specified in the factory service manual for your model year (note: ABS-equipped models may require a scan-tool bleed procedure). Monitor reservoir level constantly and refill to prevent air entry. Continue until fresh, clean fluid appears at each wheel. Top off reservoir to MAX line and verify firm brake pedal before moving vehicle.
10. 10

    Chassis lubrication
    Using grease gun filled with Moly EP grease, lubricate all grease fittings present including: front suspension ball joints (grease only those equipped with fittings; many are sealed), tie rod ends (4 fittings), steering linkage joints (2-4 fittings), driveshaft U-joints (6-8 fittings depending on configuration), and front axle slip joints (2 fittings). Pump grease into each fitting until new grease appears at joint seals or fitting becomes firm (typically 2-3 pumps). Wipe excess grease from fittings. Inspect CV joints on front axle for torn boots; replace if damaged.
11. 11

    Comprehensive inspection
    Perform thorough inspection of vehicle systems. Check all belts for cracks, glazing, or excessive wear; replace if necessary. Inspect all hoses for cracks, soft spots, or leaks. Check battery terminals for corrosion; clean if needed. Inspect all brake components including pads, rotors, and lines for wear or damage. Check all suspension components for wear, damage, or looseness. Inspect steering components for play or leaks. Check exhaust system for leaks, rust, or damage. Inspect tires for wear, damage, and proper inflation (adjust to door placard specification). Test all lights including headlights, brake lights, turn signals, and backup lights. Top off windshield washer fluid reservoir with 4 quarts all-season washer fluid. Check power steering fluid level and top off with the fluid specified on the power steering reservoir cap (Mopar power steering fluid or ATF+4 per model year).

Reassembly

1. Verify all drain plugs, fill plugs, and filter covers are properly installed and tightened
2. Confirm all fluid levels are correct and reservoirs are filled to proper marks
3. Double-check that all grease fittings have been lubricated
4. Ensure all panels, covers, and air intake components are reinstalled
5. Remove jack stands and lower vehicle to ground
6. Properly dispose of all used fluids and filters at appropriate recycling facility

Verification

• Start engine and allow to reach operating temperature while checking for any fluid leaks around filters, drain plugs, and differential covers
• Test drive vehicle for 10-15 miles, operating through all gears and verifying proper transmission shift quality
• Engage 4WD and verify proper transfer case operation and front axle engagement
• Recheck all fluid levels after test drive with vehicle on level ground and engine at operating temperature
• Verify transmission fluid level with engine running in Park on level surface (should read in HOT range)
• Check for any unusual noises from differentials or transfer case during operation
• Inspect all service areas for fluid leaks after test drive
• Reset maintenance reminder if equipped, or record service date and mileage for future reference

More procedures for this vehicle