seized duo prop

simonfraser

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this is from the yard:

'Your rear (forward-most) propeller is seized onto the drive hub. This is a spline arrangement and I suspect the two have corroded together. The way to fix this is to carefully cut the propellor off the hub (it would be slotted and prised open to remove it from the spline. The spline would then need to be carefully cleaned up). This would entail, we estimate, 7 to 8 hours labour plus the cost of a replacement propeller'

its an allu prop set up which suits me due to the shallow rivers and estuaries i boat in.

what would you guys do ?
 
From another thread:

http://www.ybw.com/forums/showthread.php?154859-Help-Stuck-on-propeller#yw1gwrwBJVRmGLdY.99

Drilling holes sounds a bit scary to me.

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Taping the blades in turn using a wooden drift for protection normally does the job. But if the props heve bee assembled with no (or the wrong type of) grease, more severe action is needed.
I had exactly the same problem with my Duoprops a few years ago. The first (4 blade) prop came off without too much problem, but the second (3 blade) was a nightmare. I managed to borrow a very large hub puller, but even using this with heavy blows on the tensioning nut was no good. The blows were cushioned by the rubber bush instead of directly on the metal inner. The cure was to get a good quality penertating oil acting on the correct area, but at first, the oil was not getting beyond the shaft end surface. The cure was to drill a series of small holes, 1-2mm dia, and 1mm (max) deep allong each of the splines in the shaft. This has the effect of removing the hardened grease which was sealing the splines, and providing a 'retainer' for the oil. With the drive leg raised, apply penetrating oil (Plus Gas is muchh better than WD40!) and leave for a few hours. Then a few taps, and Hey presto!! Wedges (1top and 1 bottom) between the front of the prop and the ring anode retaining bolts will help force off the prop instead of a puller.
I used Keynol (sp) waterproof greese when re-assembling and have no problem in subsequent years.
Hope this helps

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I cut a stainless one off a few years back (brought tears to my eyes). Took a couple of hours max.
 
This is why I remove and greasy annually... Not much good to you.

What about heat on the prop? Or would that wreck the prop shaft seals?
 
A few years ago I had the same issue both the large props stuck on shaft. we created a puller and slowly pulled the Stainless prop off of the bush, The Bush was then VERY carefully cut off the shaft, This took 5 hours for the whole operation but was cheaper than destroying 2 stainless props
 
That old chestnut. Lift the drives into trailer position. Pour boiling water down the splines. I kettle full should be plenty. Video proceedings on your mobile and then offer the mechanic to put it where the sun dont shine.

Shallow rivers and estuaries have fine silt. This gets into the grease and forms a cement. The more you pull the harder the cement gets. Just melt the grease out of the mixture and give it a few taps.
 
That old chestnut. Lift the drives into trailer position. Pour boiling water down the splines. I kettle full should be plenty. Video proceedings on your mobile and then offer the mechanic to put it where the sun dont shine.

Shallow rivers and estuaries have fine silt. This gets into the grease and forms a cement. The more you pull the harder the cement gets. Just melt the grease out of the mixture and give it a few taps.

sounds reasonable, the hot water is not going to damage the shaft seal ?
 
I think that BruceK has it right. Nothing to lose.

Having experienced this many years ago , I made a puller from a wooden disc and various bits 'n bobs to suit the 2 sizes of duoprops. Typically only had to use it once since.
The lesson to learn is to clean both the propshaft splines and those in the props (a cheap bottle-brush works a treat), then ensure both are well greased with waterproof grease prior to assembly.
 
Been there many times . No easy fix , down to very poor if at all servicing . Dry stack boats are worse because owners think they need no maintenance as marinas use that to score punters .
Every time the boat dries the salt stays inside the prop hub .
 
Read in a classic car forum site , to clean up C.V. joints some folks soak in a bucket of petrol overnight.

Similar principles ie a solvent dissolving grease .

Obviously petrol as any inflammable solvent has safety risks .
 
That old chestnut. Lift the drives into trailer position. Pour boiling water down the splines. I kettle full should be plenty. Video proceedings on your mobile and then offer the mechanic to put it where the sun dont shine.

Shallow rivers and estuaries have fine silt. This gets into the grease and forms a cement. The more you pull the harder the cement gets. Just melt the grease out of the mixture and give it a few taps.

Ok, job for Monday, will do as you suggest.
What is the size of the outer nut ?
Can i use a big wrench to take the inner castle nut off ?


And if it does not come off, how about this:
https://ez-tools.eu/Hydraulic-Gear-Puller-with-Separable-Pump-5-tons
 
As a suggestion - get a manual puller and a small diy blowtorch.
Put some tension on with the puller
Warm the body of prop up on all sides.
When its hot enough use a piece of wood against the prop and hammer the wood - this combined with the the tensioned puller should shock the prop and get it moving.
Jon
 
nope still stuck :(
puller / heat gun / hot water / shocked with hammer and wood
the forward prop is stuck, moved a bit, like 2mm, then back in it went when i released the puller

i removed ring No. 4, pulling prop No. 2
https://www.marinepartseurope.com/en/volvo-penta-explodedview-7744470-44-38149.aspx

from the previous owners records last time te props came off was September 2012
so, i am no engineer, and although i could get hold of a disc cutter, am going to leave this one to the yard to remove
should i let them have another go at pulling, or do we go straight to the cutter ?
 
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Ya, no. On since 2012? That's pushing it some and then smashing the envelope on good practise. How's the anode look?
 
yeh tell me, just been going through the previous paperwork
not sure what i paid a surveyor for at the time .....
the ring anode looks like the shield anode, see below
the trim tab anodes looked normal, as in grey holed eaten, have just replaced those they were fitted on top of AF as was the shield anode ......

the boat is now on a trailer, in the water one night a week, and has been stored on land in holland / greece or similar for a while
no evidence of a working / used mains power circuit when i bought it
so don't know how long it has been in the water for since 2012

anode 2019.jpg
 
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