Yes, there are alternative transmission lubricants that can be used in place of JOHN DEERe AM30200M for the A112-1971 lawn tractor. Look for lubricants that meet the specifications required for your tractor's transmission system, such as SAE 10W-30 or 15W-40 motor oil, or a high-quality gear oil suitable for lawn tractor transmissions. Always consult your owner's manual for specific recommendations and ensure compatibility to maintain optimal performance.