79 Mariner 140 hp shaft fretting

[sjksjk]

I just dropped the lower unit to replace the water pump impeller, I noticed on the end of the drive shaft approx 1/2 to 1" below the spines that there appears to be some wear/fretting. It looks like a shaft that has been turning in the inner race of a bearing. Is there a roller bearing up there that is below the female spline? If so how would you get the lower unit drive shaft back up thru the bearing on re-assembly? I do not have a service manual(yet). I would think that the roller bearing for the upper end of the drive shaft would be above the spline joint to allow for removal of the bottom end for service, but what could be causing this wear? Thanks for any input/advice. Stu

 

[ODDD1]

Re: 79 Mariner 140 hp shaft fretting

SJ, no bearing in there...only thing riding on the shaft below the splines is a rubber lip seal held onto the end of the crank with a stainless cup...it is there to hold grease up in the spline.....have seen the cup fall off the end of the crank and flop around in there.....maybe tis is what you are seeing?

 

[sjksjk]

Re: 79 Mariner 140 hp shaft fretting

Thanks for the help, is this a problem if not fixed? How do you get to the seal to replace it if necesary? Is this something I should have my Boat shop repair? I'm sure I could get it apart, but going back together is what's critical. Thanks.