I have a 235 with Dynin servo mounted as you describe.  My bobweight was been removed.   I’ve not had any issue without the bobweight. I’m just installing the AP now, so don’t know how it will perform.

 

 

My Tru Trak autopilot altitude hold is inconsistent, and opinions are that the servo had difficulty working properly because of the mass of the bobweight on the elevator idler arm.  One possibility is to remove the weight and expect more pitch sensitivity (lighter stick force) in turns.  Has anyone found other alternatives?

What if the mass of the bobweight is reduced?

 

My servo is behind the seat and connected to a ring clamp on the elevator control tube with a smaller, roughly parallel, rod with bearing ends.

 

Jack Dysart