Hello Ferrari Folks, Need some advice:I 'm rebuilding a water pump on a 79 308GTB. I'l stuck on how the shaft comes out. Does it come out the nose front, or the rear. I've removed the small pin (whereas the pully slides over), and can get the thing to budge. Can you give me some direction? Thank you! Chris.
Remove lock from washer on acorn nut on impeller on rear of water pump. Remove acorn nut from impeller with 2 washers Remove impeller by gently prying up on edges and or gentle heating of impeller to expand metal against shaft Remove 19mm pulley nut by torqueing against the 10mm square left on shaft by impeller Remove pulley by tapping on pulley and or gentle heating of pulley. Remove woodruffkey with pliers Remove shaft by tapping with rubber mallet in the direction of pulley to impeller. Note that the shaft presses out the rear of the water pump housing. As shaft backs out the water pump seal will pop off. You may need a punch indexed on the shaft center dimple to drive the shaft beyond the inner bearing.
Just a little clarification: The shaft does remove from the rear of the waterpump? Its in very tight. Thanks Chris.
My pumps seal went and got into the bearings. The shaft froze to the bearings. It is very difficult to get the shaft out when it is like this. Only a press will do. I tried a rubber mallet but that wouldn't work. A tip that I received was to put the pump in the oven on 250-300 for 10-15 mins. Then the bearings come out much easier. I used PB Blaster. I don't think it helped much though.
Or, heat the front part of water pump housing and let gravity cause the front bearing to drop out. It can be persuaded by using a punch, to move aside the "shaft spacer" remaining on impeller shaft removal, and driving the front bearing out in the direction of impeller to pulley.
Tod used a press and quite a bit of persuasion with a punch and mallet on mine. Took him about 5 minutes to pull it apart. However, as Skip ("Darolls") knows, he's done this a few times. You do want to be careful not to crack the housing. I don't think this is hard, but it is also not a job I'd do unless I'd seen it done elsewhere first. A small mistake will be an expensive fix.