Volvo Penta DPX question
 

Hello everyone, first post here. I purchased a boat this year with the DPX415 engine and DPX drive. I see it says DPX-S1 on the tag. Couple questions regarding these drives.

From what I've researched and think i found, im under the assumption that they dont use the typical Gimbal bearing W/ male shaft like a mercruiser. They use a PDS shaft and bearings (inside bellhousing?) With a female shaft coming out of drive.
I have a slightly rythmic noise that almost sounds like a failing water pump bearing on a car. Im concerned that the bearings need to be replaced or at least inspected. Are these serviceable without removing the engine? I have read that some have done it without engine removal but what causes someone to have to pull the engine to change them, just getting stuck in there?

The engine and drive have 580 hours on them. Doesn't have any weird vibrations or anything, and sometimes the noise isn't presant. Anyway i appreciate an insight or information.