Slim: No doubt it is cracked. In my experiences 90 plus % of them develop either 2 or 4 cracks. Take the cover off, clean it braze it on the bottom side. As far as taking the hydraulic off, it can be done without but usually we took them off which means the PTO must also be removed. If not at least take the pipes out of the unit. There is also a bolt on each side that is under the cover and threads into the side of the transmission case that must be removed. A group 3 has the handles coming out of the top. A group two has the manual handles on the side of the unit and the hydralectric switches on the steering collum. A group one has no manual handles and many do not have a filter on the unit. The electric controls are the same place as the group 2 units. Hope this helps.