is there a gear lube in my ac compressor or is it just the refri oil in the comp

There is no "gear oil" in the A/C compressor in your 1993 Dodge Dynasty. The only oil that lubricates the internal parts in the compressor is what is commonly known as the "oil charge." The oil charge resides with the refrigerant in your A/C system, and circulates throughout the A/C system along with with the refrigerant (or freon). If you are hearing a knock (or other mechanical noises) in your compressor, the compressor may have internal damage or be worn out. Here is a suggestion: With the engine cold (meaning the engine has been off for a few hours), take the key out of the ignition switch, open the hood, stand next to the passenger side front fender (perhaps wearing work gloves), and reach down to the front of your A/C compressor. Rotate the "disc" (clutch drive plate) which is the part of the compressor clutch that is closest to the passenger side inner fender. and rotate that plate in the same direction as the vehicle's tires would turn while in forward motion. If you hear or feel a mechanical "clunk" or "snap" at any point while rotating that clutch drive plate, the compressor is probably damaged, and should be replaced. But while rotating that plate, it would be normal to encounter rotational positions that would be somewhat hard to turn through, followed by rotational positions that are much easier to turn through. The hard-to-turn areas would indicate the compression cycle It is possible that all you need is an oil charge in your Dynasty's A/C system! But if you are not familiar with automotive A/C systems, that is a job you need to take to a qualified (and licensed) A/C technician.