Impellor replacement on Merc Mark 35a 1958/9?

Beckson90

Recruit
Joined
Jul 12, 2002
Messages
2
Hi! I am try to replace my impellor and have succeeded to remove the lower unit. At the base of the shaft there is a round section with 4 round holes. I believe the impellor to be below this. How is this removed and what other hurdles am I going to encounter!??
 

Yepblaze

Lieutenant Commander
Joined
Jun 1, 2001
Messages
1,686
Re: Impellor replacement on Merc Mark 35a 1958/9?

Find a spanner wrench for that circular water pump cover and unscrew it. I have used a big punch, hammer, and penetrating oil in the past. Although it's best to find the tool. <br /><br />Under that is a wear plate that you can get a knife blade under the edge of and lift out. Then below that is the impeller. Use a couple of screw drivers to pry it out of the waterpump housing. Watch out that you don't lose the pin or key device that keys it to the shaft.<br /><br /> Make note of the direction it was turning as you will need to rotate the new one as you slide it down, while maintaining the key to driveshaft.<br /><br />Put the wear plate and cover back on. <br /><br />Line up the water tube and try not to tear the rubber cup it slides into. If the rubber cup is torn they are available from any merc dealer that has the part number.<br /><br />Before you get ready to slide it back on disconnect the shift cable at motor. <br /><br />Turn the shift shaft on the lower unit through the gears and familiarise yourself with the action of the splined sahft and shift mechanism of the motor so that when you slide the lower unit back on you have at least a fighting chance of getting it up, with the water tube in it's hole, and the shifter shaft aligned. <br /><br />Good Luck and it might take a few tries to make it go back on and the shaft, and shift correctly.
 

Beckson90

Recruit
Joined
Jul 12, 2002
Messages
2
Re: Impellor replacement on Merc Mark 35a 1958/9?

Thanks Yepblaze, I'll give it a go!!
 
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