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Old 06 September 2015, 15:12   #11
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Agree with the above comments. A quick look on ebay shows one available for a lot less than they want. Just depends on what shaft yours is.
What a fantastic stroke of luck for you that they just happen to have a used gearbox in stock that they can do at a super price - how spooky is that (Or do I just have a nasty suspicious nature )
Changing a lower leg isn't difficult!
Long Shaft Gearbox Lower Unit ~ F80 F100 YAMAHA 80HP 100HP 4-Stroke Outboard | eBay
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Old 06 September 2015, 15:14   #12
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Originally Posted by Marine89 View Post
If I had hit something hard what would the likely damage be?

New prop shaft? New gearbox shaft? (is it the same thing?). Would I ever need a new gearbox shaft? Their answerphone message said it could have damaged the bearings and hence a new gearbox would be safer? Is this reasonable?

They have offered a whole new gearbox and shaft etc for 1750+vat+labour. Do I need to enquire about the origin of this second hand one?

Do you think the whistling might be related to this or not?

Thanks again so much for everyone's help- so much appreciated.
If you can see no external damage, you're looking at a some internals at worst. No way should this come to 2k.
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Old 06 September 2015, 15:18   #13
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Thanks paintman.

Would you be happy just doing the shaft rather than the whole gearbox as they think is necessary?

The fact that they happen to have the right second hand part is what made me slightly suspicious!
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Old 06 September 2015, 15:29   #14
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It's surprising how much impact a box can take without doing damage. Friend of mine trashed an alloy prop in a big way on a concrete lifeboat slip - I saw & heard it & was expecting a LOT of damage. Changed the prop & no subsequent issues at all. So I'd suggest it takes quite a lot to bend a shaft!
Difficult if you can't do your own work - I do. I'd drain the box oil & see what comes out. If there is water in it then there could be seal damage which may or may not be related to shaft issues. Could just as easily be a leaky drain/fill plug.
But if you've got no vibration issues throughout the rev range I'd renew the oil, run it & see what happens.
If you can't then I'd concur with getting a second opinion from somewhere recommended.
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Old 06 September 2015, 15:41   #15
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Bit about cavitation for you (lots on the net)
Boston Whaler | Propeller Cavitation, Causes and Corrections
"Propeller Cavitation, Causes and Corrections

Cavitation is a phenomenon that occurs in all propeller-driven craft under certain conditions. The surface of propeller blades is not perfectly flat, and as water is drawn through the blades to be discharged aft into the propeller's slip stream, the water flowing over the curved surface of the blade encounters areas of greater and less pressure. In those areas of reduced pressure, air bubbles are formed. When they move out of the low pressure area, these bubbles collapse. If they collapse while in contact with an object, such as part of the propeller blade or a trim plane, the bubbles create such highly localized forces that they erode the surface of the object. In the case of the propeller, such damage is sometimes called a "burn." It may be caused by an irregularity in the propeller's leading edge, and should be corrected by reconditioning the propeller or by replacement. Cavitation is a normal occurrence in modern boats and propeller inspection should be a part of routine maintenance."
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Old 06 September 2015, 16:02   #16
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If someone is going to strip the gearbox to fit a new shaft they will have the bearings & gears out anyway so could all be checked at the same time
Sounds to me like they can't be arsed or aren't competent to repair your box so are taking the easy (& profitable) route of trying to sell you a box at an ott price
Personally I'd ask forum members to recommend a reputable trustworthy repairer in your area for a second opinion
Water in the oil is a sign of a seal leaking so possibly needs looking at but on the other hand it could be a sales ploy
I'd politely turn down the offer get the boat back & take it elsewhere
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Old 06 September 2015, 16:03   #17
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Quote:
Originally Posted by paintman View Post
It's surprising how much impact a box can take without doing damage. Friend of mine trashed an alloy prop in a big way on a concrete lifeboat slip - I saw & heard it & was expecting a LOT of damage. Changed the prop & no subsequent issues at all. So I'd suggest it takes quite a lot to bend a shaft!
Difficult if you can't do your own work - I do. I'd drain the box oil & see what comes out. If there is water in it then there could be seal damage. But if you've got no vibration issues throughout the rev range I'd renew the oil, run it & see what happens.
If you can't then I'd concur with getting a second opinion from somewhere recommended.
Very help- thank you. If there is water in the gearbox oil, as they say, and therefore seal damage as you mention, can the seals just be redone rather than having a new gearbox?

They say there is vibration in the gearbox due to the bent shaft but I haven't noticed any vibration while running the boat. Would you keep running the boat?

Also so you think the whistling noise might be related?

Thanks again so much for your advice.
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Old 06 September 2015, 16:07   #18
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Originally Posted by beamishken View Post
If someone is going to strip the gearbox to fit a new shaft they will have the bearings & gears out anyway so could all be checked at the same time
Sounds to me like they can't be arsed or aren't competent to repair your box so are taking the easy (& profitable) route of trying to sell you a box at an ott price
Personally I'd ask forum members to recommend a reputable trustworthy repairer in your area for a second opinion
Water in the oil is a sign of a seal leaking so possibly needs looking at but on the other hand it could be a sales ploy
I'd politely turn down the offer get the boat back & take it elsewhere
Thanks for that. Any idea how much I should expect to pay (a) for the new shaft part and (b) how many hours labour to fit it?
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Old 06 September 2015, 16:08   #19
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Seals are a replaceable service item & I'd expect any other damage to be noted at the same time.
As I said, I'd renew the oil, run it & see what happens. With a view to draining & checking the new oil after a few hours. That is straightforward.
As you are having to rely on others I'd suggest collecting the boat, paying them for whatever it was you agreed to have done & then taking it to somewhere recommended.
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Old 06 September 2015, 16:19   #20
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Im sure there is a Ribnobber member that you could meet up with and check it out, sounds like a dealer rip off as pre mentioned!
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