90 hp Johnson - Bent propeller shaft

[Zudko]

Hi everyone,

It's my firts post here, but I've read a lot since the the last weeks. Very helpful and really great info here ! My first language is French, so please forgive spelling or grammar errors i could make.

Since my boat is in storage for the winter (we use snowmobiles to travel on lakes here in the cold Quebec winter ), I recently took the propeller off to have it rebuilt or to purchase a new one. I found that the propeller shaft was bent. Actually, the splines are bent...(see attached picture)

My questions:

1) Could this shaft be repaired (rebuilt) or a new one is necessary ?

2) Is it possible for me to remove the shaft and bring it to the machine shop in the eventuality that it could be repaired ? (I have a fair knowledge in mechanics but only have "standard" mechanics tools...I've read in other posts that particular tools were required to disassemble gearcase components...)

3) If yes to 1 and 2, how to proceed to remove the propeller shaft ?

If it helps: it's a 1994 90hp Johnson, model # J90TLERC, propeller is a 14x17 aluminium 3 blades (most likely OEM) and the shaft has 13 splines...

Thanks,

 

[ezeke]

Re: 90 hp Johnson - Bent propeller shaft

It is not clear from the picture what the nature of the damage is.

An OEM prop would not fit if the prop shaft splines were very badly bent.

If the prop shaft is not bent there should not be a problem with operation; and if it is bent, better service departments have special tools to straighten them.

What is the string behind the thrust bushing? Looks like monofilament.

 

[bob johnson]

Re: 90 hp Johnson - Bent propeller shaft

well it certainly looks damaged to me!!!!!!! but id call the damage a TWISTED propeller shaft. and i would say that it is UNREPAIRABLE...at least cost wise once you have it removed from the lower unit.

that said..if the shaft itself does not wobble and still runs true...you could probably still run that.....BUT it is unlikely is twisted and stayed concentric.

that shaft alone is probably $150 used and at least $375 new..and you would have to dissasemble the lower unit to replace it.

in that case you would be advized to go ahead and check all the parts in the lower unit for replacement, and might find more parts are needed.

I would also imagine the drive shaft is bent or has some damage...as it is longer and isnt as hard in the long middle section and that propeller shaft.

good luck

bob

 

[jonesg]

Re: 90 hp Johnson - Bent propeller shaft

Doesn't look damaged, there 'appears' to be a twist but that could just be the camera angle, I'd run it and see. No sense paying interest on borrowed troubles.

 

[Zudko]

Re: 90 hp Johnson - Bent propeller shaft

Thanks for the input

I have to agree with bob johnson that it's more a twisted shaft then a bent shaft. I know the picture might not be clear enough, but it appears significantly twisted to the naked eye...

The engine ran actually fine when I took the boat out of the water. I felt what I would call tiny vibrations and originally thought they were the result of an unbalanced propeller due to minor rock damage.

I will have the propeller rebuilt and see if it can be used without trying to fix anything to the shaft. I use this boat approximately 30 hours per year only for fishing, so unless it must be replaced, it will remain damaged since the fees involved appear to be significant.

Thanks again everyone,

 

[wambs8]

Re: 90 hp Johnson - Bent propeller shaft

Hi
Looks like the splines are damaged (deformed). Does not mean the shaft is twisted. The hub on the Prop would probably slip before the shaft started to twist. Have the hub checked to see if it is slipping.

Dave