Timing Chain Tensioner

Replace the timing chain tensioner on a 1972 Ford F-100 302 V8 to restore proper timing chain tension and eliminate rattling or timing slack.

Warnings

Tools required

Parts

• Timing chain tensioner assembly × 1 — Use OEM specification or Cloyes 9-5390
• Timing cover gasket × 1 — Fel-Pro TCS 45026 or OEM
• Timing cover seal × 1 — Use OEM specification
• Tensioner housing gasket or O-ring × 1 — Verify tensioner kit contents
• RTV silicone sealant (high-temp) × 1 — Permatex 81160 or equivalent
• Harmonic balancer bolt × 1 — Replace if stretched or damaged

Fluids

• 10W-30 or 10W-40 conventional engine oil — 5 qt
• Ethylene glycol green 50/50 coolant — 3 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to reach normal operating temperature, then shut off and allow to cool for 30 minutes
3. Disconnect negative battery cable
4. Drain coolant from radiator into suitable container until level is below water pump
5. Remove radiator upper hose from water pump and timing cover area
6. Remove fan shroud bolts and reposition shroud rearward for clearance
7. Remove fan clutch assembly and water pump drive belt
8. Mark distributor position relative to intake manifold for reassembly reference

Procedure

1. 1

   Remove crankshaft pulley and harmonic balancer
   Remove the 4 crankshaft pulley bolts securing the outer pulley to the harmonic balancer. Use the crankshaft pulley holding tool to prevent rotation. Once pulley is removed, install harmonic balancer puller and remove the harmonic balancer from the crankshaft snout. Note the keyway position on the crankshaft.
2. 2

   Remove timing cover access bolts
   Remove the 8 timing cover bolts that secure the front timing cover to the engine block. Start with the upper bolts and work downward. Note the different bolt lengths for reassembly. The two lower bolts also secure the oil pan to the timing cover junction.
   Torque spec

   Timing Cover Access Bolts12 Nm (9 lb-ft)
3. 3

   Separate timing cover from block
   Carefully pry the timing cover away from the engine block using a small pry bar at the designated pry points (located at upper corners). Do not pry against machined sealing surfaces. The cover may be sealed with RTV in addition to the gasket. Work slowly to avoid cracking the cover.
4. 4

   Rotate engine to TDC compression stroke cylinder 1
   Rotate the crankshaft clockwise (viewed from front) using a socket on the crankshaft bolt until the timing marks on the crankshaft sprocket and camshaft sprocket align. Verify cylinder 1 is on compression stroke by checking that both valves are closed and rocker arms are loose. The distributor rotor should point to cylinder 1 terminal position.
5. 5

   Inspect timing chain and sprockets
   With timing marks aligned, measure timing chain slack by pulling the chain away from the sprockets on the slack side (passenger side). If slack exceeds 0.5 inches, the chain should be replaced along with the tensioner. Check sprocket teeth for wear or hooking. Document timing chain condition for future reference.
6. 6

   Remove old tensioner assembly
   Locate the timing chain tensioner on the driver side of the timing chain. Remove the tensioner cap or plug using a socket. The tensioner may be spring-loaded, so control removal to prevent sudden release. Remove the 2 tensioner housing bolts and extract the complete tensioner assembly from the engine block.
   Torque spec

   Tensioner Cap/Plug30 Nm (22 lb-ft)
7. 7

   Clean tensioner mounting area
   Thoroughly clean the tensioner mounting bore in the engine block using parts cleaning solvent and a wire brush. Remove all old gasket material, RTV sealant, and debris from the mounting surface and bolt holes. Inspect the bore for cracks or damage. Ensure oil passages to the tensioner are clear and unobstructed.
8. 8

   Install new tensioner assembly
   Install new tensioner housing gasket or O-ring onto the tensioner body. Compress the tensioner mechanism fully and lock it in the retracted position using the locking pin or clip provided with the new tensioner. Insert the tensioner assembly into the engine block bore, aligning the oil feed hole. Start both tensioner housing bolts by hand.
9. 9

   Torque tensioner housing bolts in sequence
   Tighten the 2 tensioner housing bolts in alternating sequence (top bolt first, then bottom bolt) to 25.0 Nm (18.0 lb-ft). This is a critical torque specification to ensure proper tensioner alignment and prevent oil leaks. Verify tensioner is seated fully against the engine block.
   ⚠Improper torque on tensioner housing bolts can cause oil leaks or tensioner misalignment leading to premature timing chain wear.
10. 10

    Install tensioner cap with new crush washer
    22.0 lb-ft (30.0 Nm) Verified detail (The 1972 Ford 302 does not have a tensioner cap/plug. This step describes a component that does not exist on this engine.): 22.0 lb-ft (30.0 Nm)
    Torque spec

    Tensioner Cap/Plug30 Nm (22 lb-ft)
11. 11

    Release tensioner lock and verify operation
    Remove the tensioner locking pin or clip to allow the tensioner to extend against the timing chain. The tensioner should extend smoothly and apply pressure to the timing chain. Rotate the crankshaft clockwise two full revolutions by hand and verify the tensioner maintains contact with the chain throughout the rotation. Recheck timing mark alignment.
12. 12

    Prepare timing cover for reinstallation
    Remove all old gasket material from the timing cover mating surface using a scraper. Clean both the timing cover and engine block mating surfaces with parts cleaning solvent. Install new timing cover gasket and front seal onto the timing cover. Apply a thin bead of RTV silicone sealant to the oil pan-to-timing cover junction points (two locations at bottom of cover).
13. 13

    Reinstall timing cover
    Carefully position the timing cover onto the engine block, ensuring the front seal aligns with the crankshaft snout. Start all timing cover bolts by hand, noting the correct positions for different length bolts. Tighten bolts in a crisscross pattern starting from the center and working outward to 12-15 lb-ft.
    Torque spec

    Timing Cover Access Bolts12 Nm (9 lb-ft)
14. 14

    Reinstall harmonic balancer and pulley
    Ensure the crankshaft keyway is clean and free of burrs. Align the harmonic balancer keyway with the crankshaft key and install the balancer onto the crankshaft snout, tapping gently with a soft mallet if necessary. Install the harmonic balancer bolt and torque to 70-90 lb-ft. Install the crankshaft pulley with 4 bolts and tighten securely.

Reassembly

1. Reinstall water pump drive belt and adjust tension to 0.5 inch deflection with moderate thumb pressure at longest span
2. Reinstall fan clutch assembly and torque fan bolts to specification
3. Reposition fan shroud and secure with mounting bolts
4. Reconnect radiator upper hose to water pump and timing cover
5. Refill cooling system with 50/50 ethylene glycol coolant to proper level
6. Verify distributor is in original marked position for proper timing
7. Reconnect negative battery cable

Verification

• Start engine and verify no coolant or oil leaks from timing cover area or tensioner
• Listen for timing chain noise at idle - there should be no rattling or slapping sounds from the front of the engine
• Allow engine to reach normal operating temperature and recheck for leaks
• Use timing light to verify ignition timing is correct and stable (typically 6-10 degrees BTDC at idle for stock 302)
• Verify oil pressure is normal (40-60 psi at 2000 RPM when warm)
• Road test vehicle and verify smooth operation with no unusual noises from timing chain area

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