I recently made the same mistake, and I couldn't get a definitive answer from anyone I asked, and so I ordered a copy of the shop manual.Hello Rob! I have the same problem as this user (accidentally loosened one of the transmission pan bolts) and drained an ounce or two of fluid accidentally. My lawn mower is the HRR2169vka. Would my transmission have the same capacity of 5.1 ounces?
According to the manual, for the K5-K7 mowers, the capacity of the transmission case is 150 cc (5.1 oz), and for the the K8-K11 mowers, the capacity is 65 cc (2.2 oz).
I hope this information proves helpful down the line.