Certain Chrysler products had a fluid coupling that was filled with engine oil and required an oil change that drained the fluid coupling and the oil pan. 1953 was in that era. It had nothing to do with the transmission which had it's own lubricant. Most of the fluid couplings were self contained but for a couple of years they drilled the crank and filled from the engine. Made an oil change interesting as you filled the engine back up to full mark (5 qts. usually) and started the engine and dumped the rest in quickly as the oil was being pumped into the converter which was also 5 qts. too. Then you had to stop the engine and wait for the air bubbles to clear out of the oil before you were able to verify that the oil level was correct. Most perople opted for an engine only oil change rather than wait about an hour for a complete change at twice the price.