Can you drop the oil pan to change rear main seal 1984 Chevy half ton?
No, you generally cannot drop the oil pan to replace a rear main seal on a 1984 Chevy half-ton truck. The rear main seal is located at the very back of the engine, behind the flywheel, and is not accessible by removing only the oil pan. Replacing a rear main seal usually requires either removing the transmission or dropping the engine (or a combination of both, depending on the specific engine and transmission).