Front Main Seal

This procedure covers removal and replacement of the front crankshaft seal on a 1972 Ford F-100 with 302ci V8 engine, requiring removal of the radiator, harmonic balancer, and timing cover.

Warnings

Tools required

Parts

• Front crankshaft seal × 1 — Use OEM specification Ford part or equivalent
• Timing cover gasket × 1 — Use OEM specification
• Timing cover seal (water pump to timing cover) × 1 — Use OEM specification
• Harmonic balancer bolt × 1 — Recommended replacement
• RTV silicone gasket maker (anaerobic or OEM-approved) × 1 — Ford-approved RTV
• Oil pan gasket (if disturbed) × 1 — Use OEM specification

Fluids

• 10W-30 or 10W-40 conventional engine oil — 5 qt
• Ethylene glycol green 50/50 coolant — 15 qt

Preparation

1. Position vehicle on level ground and engage parking brake
2. Disconnect negative battery cable
3. Allow engine to cool completely (minimum 2 hours after operation)
4. Remove engine oil dipstick to vent crankcase
5. Place drain pan under radiator and open petcock to drain coolant completely
6. Place drain pan under oil pan and remove drain plug to drain engine oil
7. Reinstall oil drain plug after draining

Procedure

1. 1

   Remove radiator and fan shroud
   Disconnect upper and lower radiator hoses at radiator using hose clamp pliers. Remove 4 radiator mounting bolts securing radiator to core support. If equipped with fan shroud, remove mounting bolts and lift shroud away from fan. Carefully lift radiator straight up and out of engine compartment.
2. 2

   Remove fan and water pump pulley
   Remove 4 fan-to-water pump hub bolts and remove fan assembly. Remove 4 water pump pulley bolts and remove pulley from water pump hub. The pulley may require holding the water pump hub to prevent rotation during removal.
3. 3

   Remove drive belts and crankshaft pulley
   Remove all engine drive belts (alternator, power steering if equipped). Remove 4 bolts securing the outer crankshaft pulley to the harmonic balancer hub. Remove pulley.
4. 4

   Remove harmonic balancer
   Remove the large center bolt from the harmonic balancer (typically 1-1/8" or 1-1/4" socket required). Install harmonic balancer puller with center bolt threaded into crankshaft. Tighten puller forcing screw evenly to pull balancer off crankshaft. Do not use impact tools or strike the balancer.
5. 5

   Remove timing cover bolts
   Remove all timing cover mounting bolts. There are typically 10 bolts around the perimeter of the timing cover: 6 bolts through the front of the cover, and 4 bolts where the timing cover meets the oil pan. Note bolt locations as some may be different lengths.
6. 6

   Remove timing cover
   Carefully pry timing cover away from engine block using a pry bar at designated pry points (typically at bottom corners). Work around perimeter evenly to avoid cracking the cover. The timing cover seal at the oil pan may be adhered with RTV. Once free, pull timing cover straight off to avoid damaging timing chain and gears.
7. 7

   Remove old front seal from timing cover
   Using a seal puller or carefully positioned pry bar, extract the old front crankshaft seal from the timing cover bore. Work around the seal perimeter evenly to avoid damaging the timing cover bore. Clean the seal bore thoroughly with parts cleaner and inspect for damage or scoring.
8. 8

   Clean and prepare sealing surfaces
   Remove all old gasket material from timing cover mating surface on engine block using a scraper, taking care not to gouge aluminum or cast iron surfaces. Clean the oil pan-to-timing cover junction area thoroughly. Inspect crankshaft snout for wear, scoring, or damage where seal rides. Minor imperfections can be smoothed with fine emery cloth; deep grooves require crankshaft replacement.
9. 9

   Install new front crankshaft seal
   Lightly lubricate the outer diameter of the new seal with engine oil. Position seal squarely in timing cover bore with spring lip facing toward engine. Using a seal driver or appropriately sized socket that contacts only the outer seal edge (not the center), drive seal evenly into bore until fully seated and flush with timing cover face.
10. 10

    Install timing cover with new gasket
    Apply a thin bead of RTV silicone at the oil pan-to-engine block junction on both sides where timing cover will mate. Position new timing cover gasket on engine block, aligning all bolt holes. Apply light coat of engine oil to crankshaft snout and seal lip. Carefully slide timing cover over crankshaft snout, ensuring seal lip is not damaged during installation. Align timing cover using the crankshaft seal centering tool (or dowel pins if equipped) to ensure proper concentricity of the seal to the crankshaft snout before tightening.
11. 11

    Install timing cover bolts
    Install all timing cover bolts finger-tight, ensuring proper bolt locations (note any shorter or longer bolts). Tighten bolts in a crisscross pattern starting from center and working outward. Without factory torque specifications, tighten to approximately 12-18 ft-lbs uniformly in a crisscross pattern, being careful not to over-torque and crack the timing cover. Verified detail (The 1972 302 uses a stamped steel timing cover, not aluminum. Ford factory spec for 5/16" timing cover bolts is approximately 12-15 ft-lbs, which is roughly correct, but the values should be verified against a factory manual. The concern about cracking applies to aluminum covers; steel covers are more forgiving.): Tighten timing cover bolts to Ford factory specification (typically 12-18 ft-lbs for the 5/16" bolts on the stamped steel cover); verify against a factory service manual.
12. 12

    Install harmonic balancer
    Ensure crankshaft snout and balancer hub bore are clean and dry. Apply a thin coat of engine oil to crankshaft snout. Align harmonic balancer keyway with crankshaft key and slide balancer onto crankshaft by hand as far as possible. Install center bolt (new bolt recommended) and tighten. Without factory specification, tighten to approximately 70-75 ft-lbs. The balancer should seat fully against the crankshaft timing gear. Verified detail (Ford factory spec for the 302 harmonic balancer/damper bolt is typically 70-90 ft-lbs, so the torque is plausible. However, the balancer seats against the crankshaft timing gear/spacer via the bolt washer, and stating it seats 'fully against the crankshaft timing gear' is imprecise — the balancer must be drawn on with the bolt as the hub bottoms on the crankshaft snout step.): Tighten the center bolt to Ford factory specification (typically 70-90 ft-lbs); the balancer should be fully drawn onto the crankshaft snout by the bolt.
13. 13

    Reinstall crankshaft pulley and drive components
    Install crankshaft pulley onto harmonic balancer and secure with 4 bolts. Install water pump pulley and secure with 4 bolts. Install fan assembly and tighten 4 mounting bolts. Reinstall all drive belts and adjust to proper tension (1/2" deflection with moderate thumb pressure at belt center).
14. 14

    Reinstall radiator and refill fluids
    Position radiator back into core support and secure with 4 mounting bolts. Reinstall fan shroud if equipped. Reconnect upper and lower radiator hoses and secure clamps. Refill cooling system with approximately 13-15 quarts of 50/50 conventional ethylene glycol (green) coolant mixture; verify exact capacity against factory specification. Refill engine with approximately 4.5-5 quarts of 10W-30 or 10W-40 conventional engine oil (5 quarts if the oil filter was also replaced).

Reassembly

1. Reconnect negative battery cable
2. Verify all hose connections are secure and properly clamped
3. Double-check that harmonic balancer bolt is properly torqued
4. Ensure all drive belts are properly tensioned and aligned

Verification

• Start engine and allow to reach operating temperature while monitoring for leaks at timing cover
• Check for coolant leaks at radiator hoses and connections
• Verify no oil leaks from timing cover or oil pan junction
• Check engine oil level and top off if necessary after running engine
• Listen for any abnormal noises from timing cover area or front of engine
• Verify all drive belts are running smoothly without slipping or squealing
• Monitor coolant level after engine cools and top off as needed after burping air from system

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