Oil Pan Replacement

This procedure covers removal and replacement of the oil pan on a 1970 AMC Rebel Machine with 390ci V8 engine, including draining oil, raising the engine for clearance, and installing a new gasket.

Warnings

Tools required

Parts

• Oil pan gasket × 1 — Use OEM specification or Fel-Pro OS 13050
• Engine oil × 1 — 10W-30 or 10W-40 per AMC specifications
• Oil filter × 1 — Use OEM specification
• Oil pan bolts (if damaged) × 1 — Use OEM specification
• RTV silicone sealant × 1 — High-temp anaerobic sealant

Fluids

• Engine oil (10W-30 or 10W-40) — 5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely (minimum 2 hours after operation)
3. Disconnect negative battery cable
4. Raise front of vehicle and support securely on jack stands under frame rails
5. Remove front engine splash shield if equipped
6. Place oil drain pan under engine

Procedure

1. 1

   Drain engine oil
   Remove the oil drain plug from the oil pan using appropriate socket. Allow all oil to drain completely into drain pan. Remove oil filter to ensure complete drainage. Reinstall drain plug hand-tight for now (will be torqued during reassembly).
2. 2

   Disconnect exhaust system
   Disconnect exhaust pipes at the exhaust manifold flanges. On the Rebel Machine, unbolt the dual exhaust Y-pipe from both manifolds and support exhaust system with wire or jack to prevent strain on hangers. This provides necessary clearance for oil pan removal.
3. 3

   Remove engine mount bolts
   Locate the two front engine mount bolts securing the engine to the frame mounts. Remove the through-bolts from both driver and passenger side engine mounts. Do not remove the mounts from the engine block itself yet.
4. 4

   Install engine support
   Position engine hoist or support bar across the engine compartment. Attach lifting chain or strap to secure lifting points on the engine (use intake manifold bolts or designated lift brackets). Alternatively, place a wood block on a floor jack positioned under the transmission bellhousing. Apply slight upward pressure to take weight off the mounts but do not lift yet.
5. 5

   Raise engine for clearance
   Carefully raise the engine approximately 2-3 inches to create clearance between the oil pan and front crossmember. Monitor clearance at radiator, fan shroud, and distributor to prevent contact. The 390 V8 requires significant lift for oil pan removal. Use wood blocks between the frame mounts and engine mounts to hold engine in raised position.
6. 6

   Remove oil pan fasteners
   Remove all oil pan retaining bolts in a cross-pattern starting from the ends and working toward the center. The 390 V8 typically uses 1/4" or 5/16" bolts around the perimeter. Count bolts during removal to ensure all are reinstalled. Note any bolts that also secure pickup tube braces or windage trays.
7. 7

   Separate and remove oil pan
   Gently tap the oil pan with a rubber mallet to break the gasket seal. Use a pry bar carefully at the designated pry points (typically at the rear corners) if needed, being careful not to damage sealing surfaces. Work the pan free and lower it carefully, maneuvering it past the crankshaft counterweights and oil pump pickup. May require tilting and rotating the pan for clearance.
8. 8

   Remove oil pump pickup tube (if necessary)
   If oil pan cannot clear the pickup tube, remove the two bolts securing the oil pump pickup tube to the oil pump. Carefully lower the pickup tube with the oil pan. Inspect pickup tube screen for debris and ensure it is not damaged.
9. 9

   Clean gasket surfaces
   Thoroughly clean all old gasket material from both the oil pan rail and engine block mating surface using a gasket scraper. Be careful not to gouge the soft aluminum oil pan. Clean surfaces with brake cleaner and wipe dry. Inspect both surfaces for warping or damage. The oil pan rail on the block must be perfectly clean and flat for proper sealing.
10. 10

    Inspect oil pan
    Inspect the oil pan for cracks, dents, or damage especially around bolt holes. Check that the pan rail is flat by placing it on a known flat surface. Minor dents in non-sealing areas can be tolerated, but any damage to the sealing flange requires pan replacement. Clean interior of pan thoroughly.
11. 11

    Install new gasket
    Apply a thin bead of RTV sealant (approximately 1/8" bead) at the corner joints where the timing cover meets the block and where the rear main seal retainer meets the block. Position the new oil pan gasket on the oil pan, ensuring all bolt holes align. Most AMC 390 gaskets use cork or rubber with steel core. Some gaskets may have adhesive backing; others may require a thin film of sealant to hold in place.
12. 12

    Install oil pan
    If removed, reinstall oil pump pickup tube to the oil pump first, ensuring proper seating and alignment. Carefully maneuver the oil pan with gasket into position, tilting and rotating as necessary to clear crankshaft and pickup tube. Align pan with engine block and start all bolts by hand to ensure proper alignment before tightening any bolts.
13. 13

    Torque oil pan bolts
    Tighten oil pan bolts in a spiral pattern starting from the center and working outward. Typical torque specification for AMC 390 oil pan bolts is 10-12 ft-lbs, though no factory spec is available in the database. Tighten gradually in multiple passes to avoid warping the pan or crushing the gasket. Do not overtighten as this can cause leaks.
14. 14

    Lower engine and reinstall mounts
    Remove wood blocks or lower engine support to allow engine to settle back onto the motor mounts. Reinstall engine mount through-bolts and tighten securely. Remove engine support equipment.
15. 15

    Reconnect exhaust and refill oil
    Reconnect exhaust pipes to manifold flanges with new gaskets if necessary. Tighten exhaust flange bolts securely. Install new oil filter. Torque oil drain plug to approximately 25-30 ft-lbs. Refill engine with appropriate quantity and grade of engine oil (typically 5 quarts for the 390 V8). Reconnect negative battery cable.

Reassembly

1. Reverse disassembly steps, ensuring all fasteners are properly torqued
2. Use new oil pan gasket and apply RTV sealant at timing cover and rear main seal joints
3. Ensure oil pump pickup tube is properly secured and positioned
4. Install new oil filter and refill with fresh engine oil

Verification

• Start engine and allow to idle for 2-3 minutes while monitoring oil pressure gauge
• Check for leaks around oil pan perimeter, drain plug, and oil filter
• Shut off engine and wait 5 minutes, then check oil level and top off if necessary
• Inspect underneath vehicle for any oil drips after initial run
• Road test vehicle and recheck for leaks after reaching operating temperature
• Recheck oil level after road test when engine is cool

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