1984 Mercury 9.8 Long Shaft Bent Prop Shaft?

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Castin4bass

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Just bought a Mercury long shaft 9.8 with electric start. After checking it out at home I noticed that while I spun the prop in Neutral, it appeared that the prop shaft may be bent. My question is: can it be straightened and how much will it cost? Also I noticed that the engines lower unit appears to be all one piece, is that a correct assumption on this year motor?
Thanks iBoats forum!
 
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Castin4bass

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Re: 1984 Mercury 9.8 Long Shaft Bent Prop Shaft?

Castin4bass said:
Just bought a Mercury long shaft 9.8 with electric start. After checking it out at home I noticed that while I spun the prop in Neutral, it appeared that the prop shaft may be bent. My question is: can it be straightened and how much will it cost? Also I noticed that the engines lower unit appears to be all one piece, is that a correct assumption on this year motor?
Thanks iBoats forum!
Click to expand...

I forgot to mention that at the prop shaft housing at the top it looks like it's been repaired with JB Weld due to possibly a crack, how can I tell if I have any leaks around shaft seals?
 
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carholme

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Re: 1984 Mercury 9.8 Long Shaft Bent Prop Shaft?

Because you suspect the shaft to have been bent, the crack in the housing becomes highly suspect and if it were my engine, I would remove the prop and do a runout check on the prop shaft. It will be somewhat of a rough check with out the shaft being removed and set in V blocks but it should tell you if you have to go further. Do you have access to a dial indicator or someone that can do it for you?

Gerry
 
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Castin4bass

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Re: 1984 Mercury 9.8 Long Shaft Bent Prop Shaft?

carholme said:
Because you suspect the shaft to have been bent, the crack in the housing becomes highly suspect and if it were my engine, I would remove the prop and do a runout check on the prop shaft. It will be somewhat of a rough check with out the shaft being removed and set in V blocks but it should tell you if you have to go further. Do you have access to a dial indicator or someone that can do it for you?

Gerry
Click to expand...

No, I do not have a dial indicator. Can the shaft be straightened , if so how ?
 
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carholme

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Re: 1984 Mercury 9.8 Long Shaft Bent Prop Shaft?

A machine shop will tell you if they can straighten it for you but before you get into that, have you removed the prop to see how the wobble looks. The problem with trying to straighten a bent shaft is also knowing whether or not there is a twist in it.

Are you mechanically inclined? With the prop removed, you should be able to rig up a stiff wire tool that will tell you if there is significant wobble in the shaft.

Here is a shaft P/N: 44-75667A2

http://www.marinepowerservice.com/B...Num/1110203/Doc_Part_nbr/62430/pickyear/1973/

One thing I forgot to ask, is there any play in the shaft assy, ie; if you grab the prop, can you move it up and down or sideways, indicating a bearing problem?

Gerry
 
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