The rear main seal on your 1999 Honda Civic is also called the rear crankshaft seal. This seal allows the crankshaft to rotate while keeping the engine oil inside the engine. When the seal fails, engine oil can leak out of the engine. If you don’t catch and correct the problem in time, this oil leakage can cause serious damage to your engine. If you have a manual transmission, the leaking oil can also saturate the clutch pressure plate. This would require a complete clutch replacement, as well as replacement of the leaking rear main seal.
Tools Used: Tools, Jack, Jack stands, Wheel blocks, 1 foot X 1 foot piece of plywood, Lug wrench, Wrench set, Socket set, Ratchet, Extensions, Universal joint adapter for ratchet, Pickle fork, Hammer, Long nose pliers, Straight blade screwdriver, Seal remover tool, Block of wood, Drain pan, 1 gallon of the appropriate transaxle fluid
Remove the air intake ducting, which consists of the resonator, air cleaner and air intake. First loosen any clamps by turning them counterclockwise with a flat screwdriver, then remove any mounting bolts by turning them counterclockwise with a wrench. Label and then disconnect the sensors connected to the transmission under the hood. Remove the clip for the engine wiring harness.