My 410 can be described as a drippy old unit. When I first bought it I didn't monitor the oil level in the transmission close enough and once it dropped to a certain point, the system started to make some odd noises. The machine dug fine, but one of the valves next to the transmission would make a chattering noise.
The 410 and 410B are different machines, my 410 has a charge pump in the transmission, I think the B has a charge pump on the back of the main pump, but they both appear to draw off the transmission sump for their supply.
If you haven't verified your oil level yet, I'd start there.
I have searched high and low and I can't find an answer on the proper way to measure the transmission oil level in these machines. I set my level when the machine is running and since doing that, I haven't had any issues with air bubbles in the oil or noisy valves.
Jason