Pull the boat out to change prop?

davlafont

Cadet
Joined
Jun 18, 2010
Messages
28
Can a prop be removed and replaced in the water? Or must I pull the boat out? My dock is about 4' deep so I can easily stand behind the boat to do the work. Pulling the boat out is a two-person affair for us, so I'd like to avoid the need if possible.

Thanks,
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Pull the boat out to change prop?

No need to pull it out of the water. Tilt the drive all the way up and go at it. I used to change props from a towing prop to a cruising prop all the time in over 70'. Make sure you have spare prop nuts and washers unless you can see the bottom real well ......
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: Pull the boat out to change prop?

I've changed a lot of I/O and OB props in the water. Piece of cake. The biggest issue is that you need to make sure yuo do not lose the thrust washer off the bottom of the prop when you remove it. If it was greased properly they tend to stick to the bottom face of the prop and if you miss it, it can fall off as you slide the prop off the shaft. Other than that the only issue is water temp . . . Grease the "female" splines on the prop before you go back on and you don't have to mess with regreasing the shaft under water.
 

Boss Hawg

Lieutenant
Joined
Apr 9, 2009
Messages
1,433
Re: Pull the boat out to change prop?

You can change it UNDER water if you can hold your breath long enough :p
 

jaycozer

Seaman Apprentice
Joined
Jul 27, 2006
Messages
47
Re: Pull the boat out to change prop?

I have done the same on the shore at Lake Powell. Anchored the bow and went to work on prop. Had a small tube of marine grease to do what other post rec's. Fairly, easy job for me. I had done this before on the trailer and had the thrust washer fall off in the same manner. Didn't know that was the name of it at the time but just knew to take caution while easing the prop off. Should work out fine.
 

davlafont

Cadet
Joined
Jun 18, 2010
Messages
28
Re: Pull the boat out to change prop?

Thanks everyone. I though so, but it never hurts to check. Good tip on the lube...
 

sasto

Captain
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Jun 1, 2010
Messages
3,918
Re: Pull the boat out to change prop?

We have changed 36' 100 lb. props IN the water. My fault more than once. We use Teff-Gell on the inner hub before going underwater. The props have always popped off fairly easy. So I would suppose you would have no problem depending on your skills and steadyness.....and clear water if you drop something. I'd Carry a mask.
 

KRH1326

Chief Petty Officer
Joined
Sep 22, 2007
Messages
491
Re: Pull the boat out to change prop?

I hang a small shiner net ( about 3' x 3' ) under the skeg if I do a deep water swap. ;)
 

davlafont

Cadet
Joined
Jun 18, 2010
Messages
28
Re: Pull the boat out to change prop?

Checking for the thrust washer is a lot like my habit of checking for my oil filter's rubber gasket. I learned the hard way long ago that sometimes the gasket stays stuck to the block.

Follow-up question: I just took delivery of two new Solas Rubex props (purchased from iBoats.com!)--one for cruising, one for heavy watersports--and the appropriate hub to match. So should I be greasing the hub's outer surface as well as the splines? Or should I insert the hub into the prop dry and only lube the splines?

The whole point is to be able to swap easily, so I'm inclined to grease liberally. But if the rubber is meant to mate with the prop to perform properly, I don't want to screw that up.
 

jaycozer

Seaman Apprentice
Joined
Jul 27, 2006
Messages
47
Re: Pull the boat out to change prop?

A reply (I hope someone will correct if off):

I am pretty sure I have only greased the splines and put the hub in "dry". I may have needed to assist with some light and careful banging to get the hub off and put in the new one. But it was not too difficult. It may be better just to have another hub for your quick and easy swaps you are planning.

I hope it helps a little.
 

davlafont

Cadet
Joined
Jun 18, 2010
Messages
28
Re: Pull the boat out to change prop?

Thanks. I did the ol' RTFM and Rubex makes no mention of greasing the outer surface of the hub, only the shaft splines. So I'll follow the instructions...
 

davlafont

Cadet
Joined
Jun 18, 2010
Messages
28
EPILOGUE: Pull the boat out to change prop?

EPILOGUE: Pull the boat out to change prop?

Just thought I'd chime in with my After Action Review.

Bottom line up front: Even easier than changing a tire on my car.

My boat is docked in shallow water, so I waded in--ribs deep--and stood behind the stern drive. The old prop nut was not over-torqued, so the plastic prop wrench had no difficulty breaking it free. The prop and the hub came off together due to the sticksion (is that a word?) of the grease, but the two readily separated in my hands. The thrust washer stayed on the shaft, so I pulled it off too.

I inserted the Rubex hub into the 3-blade prop (15x19P), greased the splines of the hub, greased and installed a new thrust washer, and installed the prop assembly. Spacer, washer, nut, plastic wrench to discourage gorilla torque, bend tabs, done. I think I've been typing longer than it took.

I took her for a spin to see how she feels. BFG (big fat grin). Next up: 4-blade (14.5x17P).

This time, I decided to simulate a deep water swap. I raised the trim up fully, sat on the swim deck and placed my feet on the AV plate. I was able to lean forward (aft) and repeat the whole process. The hub needed some persuasion to release the prop. I have dedicated a plastic 8 oz. deadblow mallet and a short lenth of 1" wooden dowel for the purpose. It took one blow, but the assembly hadn't seen a whole lot of action. The mallet also tapped the hub into place on the 4-blade.

Repeated the assembly process and voila! Loaded the kids and the towable and was having fun in no time. I felt like a NASCAR pit crew (of one...)!

Time will tell if my mallet/dowell combo will be unnecessary or insufficient. I've also got a small inventory of spare washers and nuts to lower the stress level of dropping a part.
 

LAC_STS

Master Chief Petty Officer
Joined
Jul 1, 2010
Messages
895
Re: Pull the boat out to change prop?

I've changed the prop the same way. I just trim the drive up all the way and sit on the swim deck and put my feet on the foil or fins or whatever its called.

If I cant get the prop nut off with one hand on the prop and one on the prop nut I just put one of my feet on one of the prop blades and push my foot while I hold onto the nut with the crescent wrench. Comes right off then.
 

Thad

Lieutenant Junior Grade
Joined
Jun 8, 2009
Messages
1,028
Re: Pull the boat out to change prop?

I am constantly changing props on the water, I have learned not only as said, have extra nuts, pins washers, what have you. But I also learned to have an extra wrench:redface:.

I personally do not care for the sitting on the swim deck way. I take my life jacket and put it on upside down. Like a diaper. Zip it up and buckle it and sit in the water as if I were on a stool. I lay a piece of that "tool box no slip fabric" and lay it on the swim platform and my wife, or a buddy if he is out, lays what I need on there for me. All in all it takes about five minutes from the time we stop to the time everything is put away and back moving.
 

EricJRW

Chief Petty Officer
Joined
Feb 3, 2010
Messages
488
Re: Pull the boat out to change prop?

Just thought I would add that the instructions for my Volvo Penta QL prop specifically said lube the inner and outer surface of the hub. This may of course be prop specific (on the QL it's metal hub to metal prop), but personally I like the idea of greasing everything up.

Oh, the water is 14' under my boat dock, so I've gotten in the habit of using my John boat as a work platform. It fits perfectly between my dock and if anything drops if lands in the John boat. That has saved me more than once.
 
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