I have what I believe is a 49 ford 9n tractor I just purchased off of someone for 1100. I am in the process of replacing all the fluids but cannot seem to identify where I would fill the rear differential fluids, transmission oil, or the hydraulic oil. I see there is a fill cap right next to the starter button. Is this where the oil goes and does this take care of all three items? I have drained both rear fluids by unscrewing the rear two drain plugs. I've also changed the engine oil and didn't have any problems locations those fill and drain plugs. Any help would be greatly appreciated.