100K Service

Comprehensive 100,000-mile service for the 1970 AMC Rebel Machine with 390ci V8, including fluid changes, filter replacements, ignition system service, and complete inspection of critical wear components.

Warnings

Tools required

Parts

• Engine oil (10W-40 or 20W-50) × 1 — Use quality conventional or synthetic blend
• Oil filter × 1 — Fram PH8A or equivalent
• Air filter × 1 — AMC 390 V8 application
• Fuel filter (inline type) × 1 — 5/16" or 3/8" application
• Spark plugs (8) × 8 — Champion RJ12YC or equivalent, heat range appropriate for 390
• Ignition points set × 1 — Delco D100P or equivalent for AMC V8
• Condenser × 1 — AMC V8 distributor application
• Distributor cap × 1 — AMC 290/343/390 V8
• Rotor × 1 — AMC V8 distributor
• Spark plug wires (if worn) × 1 — 8mm or 7mm set for AMC V8
• PCV valve × 1 — AMC V8 application
• Coolant (ethylene glycol) × 1 — Use OEM specification
• Automatic transmission fluid (if applicable) × 1 — Dexron or Type A suffix A
• Differential gear oil (85W-140) × 1 — Use OEM specification
• Brake fluid (DOT 3 or DOT 4) × 1 — Use OEM specification

Fluids

• Engine oil (10W-40 or 20W-50) — 5 qt
• Coolant/antifreeze (50/50 mix) — 14 qt
• Automatic transmission fluid (if equipped) — 4 qt
• Differential gear oil (85W-140) — 3 qt
• Brake fluid (DOT 3 or DOT 4) — 1 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine and exhaust system to cool completely (at least 2 hours)
3. Gather all tools, parts, and fluids before beginning
4. Disconnect negative battery cable
5. Raise vehicle and support securely on jack stands at frame rails
6. Remove all four wheels for brake and suspension inspection
7. Place drain pans under vehicle for fluid service
8. Document current mileage and service date for records

Procedure

1. 1

   Engine oil and filter change
   Position drain pan under oil pan. Remove drain plug from oil pan and allow oil to drain completely (approximately 15 minutes). Remove old oil filter using filter wrench. Clean filter mounting surface on block. Apply thin film of new oil to new filter gasket, fill filter halfway with fresh oil, and install hand-tight plus 3/4 turn. Reinstall drain plug. Fill crankcase with 5 quarts of 10W-40 or 20W-50 oil through valve cover filler cap. Start engine and check for leaks, then recheck level after engine reaches operating temperature.
2. 2

   Replace air filter and PCV valve
   Remove wing nut from top of air cleaner assembly. Lift air cleaner lid and remove old filter element. Inspect air cleaner housing for debris and clean if necessary. Install new air filter element ensuring proper seating. Locate PCV valve in valve cover (typically passenger side). Pull PCV valve from grommet and disconnect hose. Install new PCV valve into grommet and reconnect hose. Reinstall air cleaner lid and secure wing nut.
3. 3

   Replace fuel filter
   Locate inline fuel filter between fuel pump and carburetor. Place rag under filter to catch residual fuel. Use two wrenches to loosen fuel line fittings on both sides of filter - one to hold filter body, one to turn fitting. Note fuel flow direction marked on filter body. Remove old filter and inspect lines for damage. Install new filter with flow arrow pointing toward carburetor. Tighten fittings securely but avoid overtightening to prevent line damage. Prime fuel system by cranking engine briefly, then check for leaks.
   ⚠️Fuel is highly flammable. Work in well-ventilated area away from ignition sources. Have fire extinguisher accessible.
4. 4

   Replace spark plugs
   Number and disconnect all spark plug wires at plugs, pulling only on boot. Using spark plug socket with extension, remove all eight spark plugs. Inspect old plugs for condition (fouling, electrode wear, abnormal deposits). Check and record cylinder compression if tester available. Gap new spark plugs to 0.035" using feeler gauge. Apply anti-seize compound to plug threads. Install new plugs hand-tight, then tighten 1/8 turn with socket wrench. Reconnect spark plug wires to correct cylinders in firing order 1-8-4-3-6-5-7-2.
5. 5

   Service distributor - replace points, condenser, cap, and rotor
   Remove distributor cap by releasing spring clips or removing screws. Inspect cap for cracks, carbon tracks, or erosion and replace. Remove rotor by pulling straight up. Note position of breaker point spring and wire connections. Remove point set mounting screw and disconnect wire from terminal. Remove condenser mounting screw and wire. Install new condenser and connect wire. Install new point set, leaving mounting screw slightly loose. Rotate engine by hand until rubbing block sits on distributor cam high point. Adjust point gap to 0.016" using feeler gauge, then tighten mounting screw and recheck gap. Install new rotor aligning with distributor shaft. Install new cap ensuring alignment with distributor body.
6. 6

   Set ignition timing
   Locate timing marks on harmonic balancer and timing tab at front of engine. Clean marks if necessary. Connect timing light to number one cylinder spark plug wire. Disconnect and plug vacuum advance hose at distributor. Start engine and allow to reach normal operating temperature. Aim timing light at timing marks while engine idles. Loosen distributor hold-down clamp. Rotate distributor body slowly to adjust timing to specification (typically 5° BTDC for 390, verify with emissions decal under hood). Tighten distributor hold-down clamp. Recheck timing and reconnect vacuum advance line. Adjust idle speed to approximately 700 RPM in neutral.
7. 7

   Drain and refill cooling system
   Ensure engine is completely cold. Place drain pan under radiator. Open radiator drain petcock at bottom of radiator or remove lower radiator hose at radiator. Remove radiator cap to accelerate draining. Once drained, close petcock or reinstall hose clamp. Flush system by filling with water, running engine briefly until thermostat opens, then draining again if coolant is heavily contaminated. Fill system with 50/50 mixture of ethylene glycol antifreeze and distilled water (approximately 14 quarts total capacity). Fill radiator to base of filler neck. Start engine with radiator cap off and allow to reach operating temperature while adding coolant as level drops. Squeeze upper radiator hose to purge air pockets. Install radiator cap. Check coolant protection level with hydrometer.
   ⚠️Only perform this operation on completely cold engine. Hot coolant can cause severe burns.
   ⚠Ethylene glycol is toxic to humans and animals. Clean up spills immediately and dispose of old coolant properly.
8. 8

   Service automatic transmission (if equipped)
   Locate transmission pan under vehicle. Some 1970 AMC transmissions do not have drain plugs, requiring pan removal. If pan must be removed: loosen all pan bolts, then carefully drop one corner to drain fluid into pan. Remove pan completely and clean with solvent. Replace pan gasket. If vehicle has drain plug: remove plug and drain fluid completely. Remove and clean transmission pan for inspection if accessible. Check fluid condition and look for metal particles indicating wear. Reinstall pan with new gasket or drain plug. Add approximately 4 quarts of Dexron or Type A suffix A transmission fluid through dipstick tube. Start engine, shift through all gears, then check level with engine at operating temperature in neutral or park. Add fluid as necessary to reach full mark on dipstick.
9. 9

   Change differential gear oil
   Locate differential cover on rear axle housing. Remove all cover bolts except top two. Loosen top bolts to allow cover to tilt and drain fluid into pan. Once drained, remove cover completely. Clean cover and housing mating surfaces thoroughly with scraper and solvent. Inspect internal gears and bearings for excessive wear, scoring, or metal particles. Install new gasket or apply RTV silicone gasket maker to cover. Reinstall cover bolts in crisscross pattern. Locate fill plug on front of differential housing (approximately halfway up). Remove fill plug. Using fluid pump or squeeze bottle, fill differential with 85W-140 gear oil until level reaches bottom of fill hole (approximately 3 quarts). Reinstall fill plug.
10. 10

    Inspect and service brakes
    With wheels removed, inspect brake linings on all four wheels for wear, contamination, and remaining thickness. Minimum lining thickness should be 1/8" above rivet heads or backing plate on bonded linings. Inspect drums for scoring, cracks, or heat checking. Measure drum diameter if tools available and compare to maximum diameter stamped on drum. Check wheel cylinders for leaks by pulling back dust boots. Inspect brake lines and hoses for corrosion, cracks, or chafing. Check fluid level in master cylinder reservoir and top off with DOT 3 or DOT 4 brake fluid if low. If fluid is dark or contaminated, perform complete brake fluid flush.
    ⚠Brake dust may contain asbestos in older vehicles. Use wet cleaning methods and avoid creating airborne dust.
11. 11

    Lubricate chassis and suspension
    Using grease gun, lubricate all grease fittings on suspension and steering components. Typical locations include: upper and lower ball joints (4 total), tie rod ends (4 fittings), idler arm, pitman arm, and any universal joints on driveshaft if equipped with fittings. Pump grease into each fitting until fresh grease appears at boot seals, indicating complete filling. Wipe away excess grease. Inspect all rubber bushings and boots for cracks, tears, or deterioration.
12. 12

    Inspect belts, hoses, and suspension components
    Check all drive belts (fan/alternator, power steering if equipped, air conditioning if equipped) for cracks, glazing, fraying, or improper tension. Replace any questionable belts. Belt should deflect approximately 1/2" under moderate thumb pressure at longest span. Inspect all cooling system hoses for cracks, soft spots, or swelling. Squeeze hoses to check condition. Check hose clamps for tightness. Inspect all suspension components for wear: check ball joint boots for tears, tie rod ends for excessive play, shock absorbers for leakage, and springs for sagging or damage. With wheels off ground, check wheel bearings for play by grasping tire at 12 and 6 o'clock positions and attempting to rock wheel. Excessive movement indicates bearing adjustment needed.
13. 13

    Inspect tires and adjust pressures
    Thoroughly inspect all four tires plus spare for tread depth, uneven wear patterns, cuts, bulges, or embedded objects. Measure tread depth using gauge or penny test (minimum 2/32" depth, replace at 3/32" or less). Look for abnormal wear patterns indicating alignment or suspension issues: center wear indicates overinflation, edge wear indicates underinflation, one-side wear indicates alignment problem, cupping indicates worn suspension components. Inflate all tires including spare to specification shown on driver door jamb placard (typically 26-28 PSI for 1970 vehicles, but verify). Rotate tires if uneven wear is present and tires have sufficient remaining life.
14. 14

    Road test and final inspection
    Reinstall all four wheels and torque lug nuts in star pattern. Lower vehicle from jack stands. Reconnect battery negative cable. Start engine and verify proper operation: check for smooth idle, unusual noises, or leaks. Allow engine to reach full operating temperature and recheck all fluid levels including oil, coolant, transmission, and brake fluid. Test drive vehicle at various speeds checking for: proper engine performance and acceleration, smooth transmission shifting, proper brake operation without pulling or noise, unusual vibrations or handling issues, warning light operation. Return to shop and recheck underneath for any fluid leaks from recent service work. Check engine oil level once more after test drive.

Reassembly

1. Ensure all drain plugs, fill caps, and covers are properly installed and tightened
2. Double-check that all fluid levels are correct after reaching operating temperature
3. Verify all electrical connections are secure and battery is properly reconnected
4. Confirm wheels are properly torqued to specification
5. Clean up any spilled fluids from engine bay and undercarriage

Verification

• Engine starts easily and idles smoothly at approximately 700 RPM
• No fluid leaks visible under vehicle after test drive
• Engine reaches normal operating temperature without overheating
• All gauges read normal: oil pressure 30-50 PSI at operating temperature, coolant temperature 180-195°F
• Brakes operate smoothly without pulling, noise, or excessive pedal travel
• Transmission shifts smoothly through all gears without slipping or harsh engagement
• No unusual noises from engine, drivetrain, or suspension during test drive
• Timing verified with timing light at specified setting per emissions decal
• All warning lights function properly and extinguish after engine start
• Document all service performed including parts used, fluids added, and current mileage

More procedures for this vehicle