Sherwood Impeller – cannot get new impeller in

[Robert Connolly]

Looking for some help. Not the first time changing impellers, but first time on this boat and QSM 11’s. Sherwood pumps with 18000 impeller. No issue getting the old one out, which was in perfect condition. Had already bought the new ones as a proactive maintenance issue, so tried to install it. I greased the first 2-3 inches in the pump itself and twisted the new impeller in. It’s in a bad spot and leverage is very hard to exert. I got the new impeller in roughly halfway and then could not insert any further. Tried twisting, changing angles, even got a crowbar at one point. I ended up pulling the impeller back off 3 times and still was unable to get it in. After 2 hours, and filthy covered in sweat, grime, and blood I gave up for the night. Boat is now unusable with the impeller halfway in. Any tips or ideas are very much appreciated. Thank you.

Topic

[firehoser75]

Mathew,
I am having a bit of a problem picturing what you are describing.
Is the PVC pipe the same diameter (outside diameter) as the pump opening, larger or smaller? Does the PVC get pushed into the pump body in any way (kind of like the tool Richard describes)? How does the inside diameter of the PVC compare to the diameter of the impeller as it comes out of it’s packaging? Did you use a dowel that is close to the diameter of the impeller or much smaller?
Just trying to envision exactly what worked for you.
Thanks,
Tom

[Matthew]

Pvc impeller cheater

I use a short piece of pvc, compress the impeller into the pvc bout 1/2 way. Align the impeller with the pump and push the exposed half into the pump. When it’s aligned, use a doll rod to push the impeller out of the pvc and into the pump. The pvc pipe gives you a little leverage and if you have enough room you can look through the pvc to visually align the impeller.

[Richard Dodson]

Call Blister Marine, 310-397-8543
They have a tool, kinda like a cylinder fluted at one end. Anyway, you coat it with soap or whatever, twist and push the inpellor into the cylinder. Take that assembly and insert it into the pump housing. Twist it until the keyway aligns and insert the key. Turn and gently pull the tool out of the housing. It takes about 2 minutes to install a new inpellor . One of the best tools I have , cost around 90.00.

[Robert Connolly]

Got it done

I did have the correct impeller. Just had no leverage at all with the oil fill and dipstick right in front of the pump. Got a tip from a mechanic to get a 2×4 for some leverage and then have someone briefly “bump” the start button without allowing the engine to start. Worked amazing. 2 “bumps” and the impeller was seated. It took 5 minutes. Great lesson for me. Always more than one way to skin a cat. Thanks for the help all.

1 user thanked author for this post.

John

[Robert Connolly]

Thank you Tony. First thing I will check tomorrow.

[Tony Athens]

QSM11–Early pump design vs later pump design

Spline count & QSM11 impellers———Early pump shaft = 14Teeth, later version =10Teeth

Does the impeller you bought match the proper shaft spline tooth count?

I’d certainly start with that…………….

Understand that the average Cummins dist or dealer “parts counter monkey” has no clue about that..You need to educate them.

[Robert Connolly]

Great advice. Thank you!

[Fireisland1]

First thing I would do is put your old on back in. That proves that the shaft did not get damaged taking it off and that you have to ability to actually install it due to bad access. It is possible your new splined impeller does not fit. The spline could be cut wrong. You could try 4 thin tie wraps. Collapse the impeller evenly . That reduces all side wall friction. Then install . You can cut the ties easily after its in. If it doesn’t go then, you have a spline interference fit and the impeller is no good or the needle files have to come out.

[Author]

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