GM Full Size Vans 1967-1986 Repair Guide

Oil Pan

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REMOVAL & INSTALLATION



Inline Six Cylinder Engine
1967-69 MODELS
  1. Disconnect the negative battery terminal.
  2.  
  3. Remove the fan and pulley.
  4.  
  5. Remove the engine splash shields if equipped.
  6.  
  7. On vehicles with automatic transmissions, disconnect and plug the cooler lines.
  8.  
  9. Drain the radiator and disconnect the lower radiator hose at the radiator.
  10.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. If equipped, remove the accessory drive pulley and shroud.
  2.  
  3. Install a support under the damper.
  4.  
  5. Place a jack under the support on the damper and jack the engine to clear the front mounts.
  6.  
  7. Remove the crossmember to frame bolts and lower the crossmember to rest on the front springs.
  8.  
  9. Drain the oil and remove the oil pan. Discard the gaskets and seals.
  10.  
  11. Installation is the reverse of removal. Use new gaskets and a new seal in the rear main bearing cap and crankcase front cover. Do not use sealer. Fill the engine with coolant and oil. Start the engine and check for leaks.
  12.  

1970-75 MODELS
  1. Disconnect the negative battery terminal.
  2.  
  3. Raise and support the vehicle. Disconnect the starter leaving the wires attached and swing it out of the way.
  4.  
  5. If there is not enough clearance, remove the bolts securing the engine mounts to the crossmember and raise the engine high enough to insert a 2 in. x 4 in. (51mm x 102mm) piece of wood between the engine mounts and the crossmember brackets.
  6.  
  7. Drain the engine oil.
  8.  
  9. Remove the flywheel and converter cover.
  10.  
  11. Remove the oil pan.
  12.  
  13. Clean all gasket surfaces and install a new seal in the rear main bearing groove and a new seal in the crankcase front cover. Installation is the reverse of removal. Install new side gaskets on the block, but do not use sealer. Fill the engine with oil and run the engine, checking for leaks.
  14.  

1976-77 MODELS
  1. Disconnect the battery ground cable.
  2.  
  3. Drain the oil.
  4.  
  5. Remove the starter.
  6.  
  7. Remove the manual transmission flywheel splash shield or the automatic transmission converter housing underpan.
  8.  
  9. Support the front of the engine. Remove the engine mount through-bolts.
  10.  
  11. Raise the front of the engine enough to replace the through-bolts in the engine half of the mounts.
  12.  
  13. Lower the engine and remove the pan bolts.
  14.  
  15. Clean all gasket surfaces and install a new seal in the rear main bearing cap and on the crankcase front cover. Install new side gaskets to the block, using sealer.
  16.  
  17. Replace the pan.
  18.  
  19. Raise the engine and replace the mount through-bolts. Fill the engine with oil and run it, watching for leaks.
  20.  

1978 AND LATER MODELS
  1. Disconnect the negative battery cable and remove the engine cover.
  2.  
  3. Remove the air cleaner and studs.
  4.  
  5. Remove the fan finger guard.
  6.  
  7. Remove the radiator upper supporting brackets.
  8.  
  9. Raise the van on a hoist.
  10.  
  11. On vans with manual transmissions:
    1. Disconnect the clutch cross shaft from the left front mounting bracket.
    2.  
    3. Remove the transmission-to-bell housing upper bolt.
    4.  
    5. Remove the transmission rear mounting bolts and install two 7 / 16 in. x 3 in. (11mm x 76mm) bolts.
    6.  
    7. Raise the transmission and place small pieces of 2 in. x 4 in. wooden blocks in between the mount and the crossmember.
    8.  

  12.  
  13. Remove the starter motor.
  14.  
  15. Drain the engine oil.
  16.  
  17. Remove the engine mount through-bolts.
  18.  
  19. Raise the engine slightly and place small 2 in. x 4 in. wooden blocks in between the mount and the block.
  20.  
  21. Remove the flywheel splash shield or the converter cover, as applicable.
  22.  
  23. Remove the oil pan attaching bolts and remove the oil pan.
  24.  
  25. Clean the gasket surface thoroughly and use a new gasket on installation.
  26.  
  27. Reverse the procedure to install.
  28.  

4.3 Liter V6 Engines

A one piece type oil pan gasket is used.

  1. Disconnect the negative battery cable. Raise the vehicle, support it safely, and drain the engine oil.
  2.  
  3. Remove the exhaust crossover pipe.
  4.  
  5. Remove the torque converter cover (on models with automatic transmission).
  6.  
  7. Remove the strut rods at the flywheel cover.
  8.  
  9. Remove the strut rod brackets at the front engine mountings.
  10.  
  11. Remove the starter.
  12.  
  13. Remove the oil pan bolts, nuts and reinforcements.
  14.  
  15. Remove the oil pan and gaskets.
  16.  
  17. Thoroughly clean all gasket surfaces and install a new gasket, using only a small amount of sealer at the front and rear corners of the oil pan.
  18.  
  19. Installation is the reverse of the removal procedure.
  20.  

Gasoline V8 Engines

  1. Drain the engine oil.
  2.  
  3. Remove the oil dipstick and tube.
  4.  
  5. If necessary remove the exhaust pipe crossover.
  6.  
  7. If equipped with automatic transmission, remove the converter housing pan.
  8.  
  9. Remove the starter brace and bolt and swing the starter aside.
  10.  
  11. Remove the oil pan and discard the gaskets.
  12.  
  13. Installation is the reverse of removal. Clean all gasket surfaces and use new gaskets to assemble. Use gasket sealer to retain side gaskets to the cylinder block. Install a new oil pan rear seal in the rear main bearing cap slot with the ends butting the side gaskets. Install a new front seal in the crankcase front cover with the ends butting the side gaskets. Fill the engine with oil and check for leaks.
  14.  

Diesel Engines

  1. Remove the vacuum pump and drive (with A/C or the oil pump drive (without A/C).
  2.  
  3. Disconnect the batteries and remove the dipstick.
  4.  
  5. Remove the upper radiator support and fan shroud.
  6.  
  7. Raise and support the car. Drain the oil.
  8.  
  9. Remove the flywheel cover.
  10.  
  11. Disconnect the exhaust and crossover pipes.
  12.  
  13. Remove the oil cooler lines at the filter base.
  14.  
  15. Remove the starter assembly. Support the engine with a jack.
  16.  
  17. Remove the engine mounts from the block.
  18.  
  19. Raise the front of the engine and remove the oil pan.
  20.  
  21. Installation is the reverse of removal.
  22.  

 
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