Removing impeller from the driveshaft

PmDavis300 · Feb 19, 2008

so i took apart the lower unit last weekend, and im going to be ordering a water pump repair kit shortly, so i dissasembled the water pump, but i cant figure out how to get the impeller off. i believe i have to remove the impeller key? i think i see what it is on the drive shaft, but how do i remove it?

polk county · Feb 19, 2008

Re: Removing impeller from the driveshaft

I think that you can hold the key with a flat head screwdriver while pulling the impeller upward. Keep the old key in case you lose the new one. They are very easy to lose.

seahorse5 · Feb 19, 2008

Re: Removing impeller from the driveshaft

It would help to post the engine model number so we would know what motor you have.

Some outboards use a woodruff key and others use a pin or a wedge to drive the impeller.

Lou Eppell · Feb 19, 2008

Re: Removing impeller from the driveshaft

Ball peen hammer.... hit impeller one way, then the other. If still stuck, cut rubber in one area to expose hub. Split hub with chisel.

ezeke · Feb 19, 2008

Re: Removing impeller from the driveshaft

As seahorse5 said, method is entirely dependent on which motor you have. That should certainly be given before beating the unit with a ball peen hammer.

On the older units that have a slot in the brass retainer, cut behind the slot after removing the rubber if the impeller has corroded to the shaft.

When you put the new impeller on, grease the shaft first with Triple Guard or similar marine grease.

PmDavis300 · Feb 20, 2008

Re: Removing impeller from the driveshaft

sorry i figured they were all pretty similar. its an evinrude 1959 50hp v4

ezeke · Feb 20, 2008

Re: Removing impeller from the driveshaft

I would soak the shaft and impeller with penetrating oil -PB Blaster works well - then see if the impeller has any play by holding the driveshaft while turning the impeller. Then try lifting it from several directions. If needed, you can get a dremel with a small cutting wheel and cut the brass ring from behind the slot and then spread the ring.

PmDavis300 · Feb 20, 2008

Re: Removing impeller from the driveshaft

ok ill try that, where does one aquire pb blaster?

HighTrim · Feb 20, 2008

Re: Removing impeller from the driveshaft

Where are you from?

Most auto parts types stores in the US carry it, such as Auto Zone etc...

PmDavis300 · Feb 20, 2008

Re: Removing impeller from the driveshaft

HighTrim said:
Where are you from?

Most auto parts types stores in the US carry it, such as Auto Zone etc...

View attachment 9308

im in minnesota. theres a napa right by my place, ill check them out

PmDavis300 · Feb 20, 2008

Re: Removing impeller from the driveshaft

so just to make sure i have this straight, in an ideal situation one should just be able to tug off the impeller without worrying about the impeller key or anything?

ezeke · Feb 20, 2008

Re: Removing impeller from the driveshaft

Ideally, the key keeps the impeller turning with the driveshaft, but should not prevent it from going up and down. Greasing the shaft under the metal ring of the impeller with waterproof grease will help to keep it that way.

PmDavis300 · Feb 20, 2008

Re: Removing impeller from the driveshaft

ok thanks, that makes more sense, it did appear to be corroded on there, but i wasnt sure

HighTrim · Feb 20, 2008

Re: Removing impeller from the driveshaft

Just as a side note, ensure you add some of that marine grease to the splines of the drive shaft before you re install the lu. Same reasoning, you want to be able to drop it with ease the next time.

Removing impeller from the driveshaft

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