Oil pan for automotive engine

An oil pan structure of generally rectangular cup-like configuration having a deep region and a shallow region, said shallow region being defined adjacent a rear end of the oil pan adapted to be connected with a clutch housing, an upper portion of the rear end adjacent the opening of the oil pan structure being formed with a sealing region to be held in tight contact with a cylinder block, the oil pan comprising a reinforcement wall structure formed with the oil pan structure so as to protrude away from the rear end towards the clutch housing, said reinforcement wall structure defining a space between the rear end of the oil pan structure and the clutch housing when the oil pan structure is secured to the clutch housing, said reinforcement wall structure having a portion cut away to define an access opening communicated with the space, and a plurality of reinforcement walls integral with the rear end of the oil pan structure and encompassing a lower portion of the rear end, said reinforcement walls having generally arcuate joint faces adapted to be held in contact with the clutch housing, said at least one bolt receiving boss being located between the reinforcement walls and immediately above the access opening, said access opening being located immediately below at least one bolt receiving boss formed in the rear end of the oil pan structure for the passage of a fitting bolt used to connect the oil pan structure from below to a cylinder block and being open towards the clutch housing, and a cover member removably fitted to the reinforcement wall structure for closing the access opening, the cover member being of a sectional shape generally similar to the inverted shape of a figure "L" and having an upper portion adapted to be bolted to a ribbed wall integral with the oil pan structure and a lower portion adapted to be bolted to the clutch housing.