100K Service

Complete 100,000 mile service including all fluid changes, filters, and inspections for the 5.9L Cummins diesel engine and 4WD drivetrain components.

Warnings

Tools required

Parts

• Engine oil filter × 1 — Mopar 5083285AA or equivalent
• Fuel filter/water separator assembly × 1 — Mopar 5083285AB or equivalent
• Air filter element × 1 — Use OEM specification
• Crankcase vent filter × 1 — Use OEM specification
• Transmission filter and pan gasket kit × 1 — Use OEM specification
• Front differential cover gasket × 1 — Use OEM specification
• Rear differential cover gasket × 1 — Use OEM specification
• Transfer case gasket or RTV sealant × 1 — 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

Preparation

1. Park vehicle on level surface and engage parking brake
2. Place wheel chocks behind rear wheels
3. Allow engine, transmission, and drivetrain to cool completely (minimum 2 hours)
4. Gather all fluids, filters, and tools before beginning
5. Raise and support vehicle safely on jack stands at all four corners for undercarriage access
6. Remove skid plates if equipped to access drain plugs and filters

Procedure

1. 1

   Engine oil and filter change
   Place drain pan under oil pan. Remove oil drain plug from bottom of oil pan and allow oil to drain completely. Remove oil filter using filter wrench - be prepared for additional oil spillage. Clean filter mounting surface. Apply thin film of clean oil to new filter gasket. Install new filter hand-tight plus 3/4 turn. Reinstall drain plug with new crush washer if available. Fill engine with approximately 11 quarts of 15W-40 diesel engine oil through oil fill cap (verify exact capacity for your model year), then check dipstick.
2. 2

   Fuel filter/water separator replacement
   Locate fuel filter/water separator assembly on driver side of engine. Place drain pan underneath. Open water drain valve at bottom of filter housing and drain water and fuel. Close drain valve. Use fuel filter wrench to remove filter canister by turning counterclockwise. Clean mounting surface on filter head. Fill new filter approximately 3/4 full with clean diesel fuel to aid priming. Lubricate gasket on new filter with diesel fuel. Thread filter on by hand until gasket contacts base, then tighten 3/4 to 1 full turn. Prime the fuel system: on models with a manual primer plunger on the lift pump, pump until firm; on models with an electric lift pump, cycle the key to run the pump. Then crank engine in short bursts until it starts. Check for leaks.
3. 3

   Air filter and crankcase vent filter replacement
   Open air filter housing by releasing clamps on top of air box. Remove old air filter element and inspect housing for debris or moisture. Clean housing if necessary. Install new air filter element ensuring proper seating. Locate crankcase vent filter on valve cover (small cylindrical filter). Twist and pull to remove old filter. Press new filter firmly into place until seated. Close and secure air filter housing.
4. 4

   Automatic transmission service
   Locate transmission pan underneath vehicle. Position large drain pan underneath transmission pan. Remove all pan bolts except two at one corner, loosening those two bolts several turns to allow pan to tilt and drain. Once drained, remove remaining bolts and lower pan carefully. Remove old transmission filter by pulling straight down - some fluid will spill. Clean pan thoroughly with brake cleaner and shop towels, paying special attention to magnet. Inspect magnet for excessive metal debris (small amount is normal). Install new filter by pressing firmly into place. Install new gasket on pan. Reinstall pan and torque bolts in criss-cross pattern to manufacturer specification. Refill transmission with approximately 4-6 quarts of Mopar ATF+4 (pan drop returns only partial capacity, not full dry fill) through dipstick tube, then check level. Start engine and cycle through all gears, then check level with engine running in park and add fluid as needed (note: use ATF+4 for 1998+; earlier models originally specified ATF+3/Dexron, though ATF+4 is generally backward-compatible).
5. 5

   Transfer case fluid change
   Locate transfer case behind transmission. Clean area around drain and fill plugs. Remove fill plug first (upper plug) to ensure it's not seized. Place drain pan under transfer case and remove drain plug (lower plug). Allow fluid to drain completely. Reinstall drain plug. Using fluid transfer pump, add approximately 2 quarts of Mopar ATF+4 through fill hole until fluid begins to drip out. Install fill plug and tighten securely.
6. 6

   Front differential service
   Locate front differential housing. Clean around differential cover bolts. Position drain pan under differential. Remove all cover bolts and carefully pry cover off - fluid will drain quickly. Once drained, clean cover and housing mating surfaces thoroughly, removing all old gasket material. Inspect ring and pinion gears for damage or excessive wear. Install new gasket on cover (or apply RTV sealant per gasket instructions). Reinstall cover and torque bolts in criss-cross pattern. Locate fill plug on front of differential housing and remove. Using fluid pump, add approximately 2.5 to 3 quarts of 75W-90 synthetic gear oil through fill hole until fluid reaches bottom of fill plug hole (verify capacity for Dana 44 vs Dana 60 front axle). Reinstall fill plug.
7. 7

   Rear differential service
   Locate rear differential housing. Clean around differential cover bolts. Position drain pan under differential. Remove all cover bolts and carefully pry cover off. Once drained, clean cover and housing mating surfaces thoroughly. Inspect ring and pinion gears for damage. Clean and inspect magnetic drain plug. Install new gasket on cover. Reinstall cover and torque bolts in criss-cross pattern. Locate fill plug on the rear differential housing or cover (typical for Dana 70/80 or 10.5 AAM axle) and remove. Using fluid pump, add approximately 3.5 to 4 quarts of 75W-90 synthetic gear oil through fill hole until fluid reaches bottom of fill plug hole (verify capacity for your rear axle; add limited-slip friction modifier if equipped with LSD). Reinstall fill plug.
8. 8

   Coolant inspection and service
   With engine completely cool, remove radiator cap. Inspect coolant condition - should be clean green (1994-2000 models with conventional coolant) or orange/red (2001+ models with HOAT formula). Check level in overflow reservoir. If coolant is dirty, rusty, or more than 5 years old, perform complete coolant flush: Open radiator petcock at bottom of radiator and drain into appropriate container. Close petcock. Fill system with distilled water, run engine to operating temperature with heater on full, allow to cool, and drain again. Repeat if necessary. Fill system with 50/50 premixed coolant until full (verify system capacity, approximately 20-24 quarts total for the 5.9L Cummins; a petcock drain will require less refill volume since the block does not fully drain). Run engine with radiator cap off until thermostat opens, adding coolant as needed. Reinstall radiator cap and fill overflow reservoir to proper level.
9. 9

   Brake fluid exchange
   Check brake fluid reservoir level and condition. If fluid is dark or contaminated, perform brake fluid flush starting at wheel farthest from master cylinder (right rear), then left rear, right front, left front. Have assistant pump brake pedal and hold pressure while you open bleeder screw at each wheel, catching old fluid in container. Close bleeder before pedal reaches floor. Repeat until fluid runs clear at each wheel. Keep master cylinder reservoir topped off with fresh brake fluid meeting the specification marked on the master cylinder cap (DOT 3 for most models) throughout process. Top off reservoir to proper level when complete.
10. 10

    Chassis lubrication
    Locate all grease fittings (zerks) present on front suspension and steering components, which may include ball joints (if greasable), tie rod ends, track bar end, drag link, and driveshaft U-joints/slip yokes. Note some OE ball joints are sealed and non-greasable. Clean each fitting before greasing. Using grease gun with synthetic grease, pump grease into each fitting until clean grease purges from boot or seal (typically 2-3 pumps per fitting). Wipe away excess grease. Check steering linkage for play or damage during this process.
11. 11

    Belt inspection and adjustment
    Inspect serpentine drive belt for cracks, glazing, fraying, or missing ribs. Check belt tension - should have approximately 1/2 inch deflection at longest span. If belt requires replacement or adjustment, loosen tensioner and adjust or replace belt. On manual tensioner models, adjust to proper tension and tighten lock bolt. Check all pulleys for smooth operation and bearing noise.
12. 12

    Final inspections
    Inspect all hoses and lines for leaks, cracks, or damage including coolant hoses, fuel lines, brake lines, and power steering hoses. Check battery terminals for corrosion and clean if necessary. Inspect tires for wear and check pressure. Rotate tires if appropriate. Check all fluid levels one final time. Inspect exhaust system for leaks or damage. Check front axle U-joints and axle shaft seals for wear or leakage (this solid front axle has no CV boots). Lower vehicle from jack stands and reinstall skid plates if equipped.

Reassembly

1. Reinstall any skid plates or protective panels removed during service
2. Lower vehicle to ground and remove jack stands
3. Double-check all drain plugs, fill plugs, and filter installations for tightness

Verification

• Start engine and check for oil leaks around filter and drain plug
• Verify oil pressure gauge shows normal pressure within 5 seconds of starting
• Check for fuel leaks around fuel filter - let engine run for 2 minutes
• With engine at operating temperature, verify no coolant leaks and proper coolant level
• Test drive vehicle through all gears to verify transmission operation and check for leaks afterward
• Verify proper 4WD engagement if equipped with manual or electronic transfer case
• Recheck all fluid levels after test drive and top off if necessary
• Verify no unusual noises from differentials or transfer case during test drive
• Check brake pedal feel and operation - should be firm with no sponginess

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