Sierra Impeller Installation

[60sboater]

It's a 73 9.8hp and had a merc impeller and replacing with equiv Sierra(18-3039). The sierra has stiffer vanes and it is much harder to get into the cup after engaging the key. I've heard of using zip ties and tried it but didn't work for me. I can get it half way in and the key is in the keyway but the stiffness of the vanes is fighting my efforts to get it all the way in. I installed a Merc impeller (47-89981) one time and it went in fairly easily...vanes were not as stiff.

any tips ?

 

[60sboater]

Never mind,I got it installed with a pvc pipe as a helper.

 

[Dekker500]

For future reference, I found using a bit (less than you think you need) of marine lube helpful. Wipe a thin film on the ends of the vanes and around the inside of pump housing. As you lower the impeller but before it reaches the key, rotate clockwise to impart the appropriate "spin", and stop rotating once the key is lined up with the slot in the impeller. Then you can just push straight down, over the key, and the vanes should slide down nicely. This assumes you have visually marked where the slot is on the impeller.

Mine is an '85 9.8hp, and that's how I get it in...

 

[60sboater]

I did lube with WD-40...grease may be better or preferred. The Sierra is harder to get in than a Merc impeller...done both. With the Merc one,I pushed it in w/o extra mechanical assistance. I marked the keyway with marine grease.

 

[minuteman62-64]

I use the procedure recommended in my repair manual. Install impeller on key, lube housing and plate (manual says grease, some guys use dishwashing soap), turn drive shaft clockwise while pushing housing down over impeller. Never had a problem with either Sierra or OEM impeller.