68 model 39 - leaking lower unit

[mattdd]

i just bought a '68 model 39. first thing i did was drain the lower unit grease as well as take off the lower unit to inspect the impeller. the grease, which had been in the lower unit for just a few minutes while it ran in a 55g drum, was milky. and there was some grease in the water pump area. i pulled the lower water pump housing and there was water around the inner seal. are the seals factory installed into the lower housing? the seal had the flat end with the numbers facing out....so the lip part was pointing towards the impeller.

second thing is the notch for the impeller key is wide, but the key looks like a needle bearing, and looks like it fits the impeller. is this the correct key?

 

[Chinewalker]

Re: 68 model 39 - leaking lower unit

Most of those old Mercs leak lower unit oil at this point. Not a seal issue, rather a shaft issue. Mercury was late to the stainless steel dance and used carbon steel shafts that would rust over time. Typically, this was at the waterpump base seal and at the propshaft seal. They make stainless speedisleeves that can salvage lightly pitted shafts...

 

[mattdd]

Re: 68 model 39 - leaking lower unit

Like these.....http://www.alliedbearings.com/mfg_prod/seals/cr_speedi/index.html

the shaft really didn't look that bad, but the area around the seal is slightly pitted. any idea on the sleeve width?

 

[Chinewalker]

Re: 68 model 39 - leaking lower unit

Just something that won't interfere with the waterpump or the bearing below it...

 

[mattdd]

Re: 68 model 39 - leaking lower unit

took a closer look this evening and there is a grove worn into the shaft at top and bottom water pump seal. i measured .454 and .453 at the bottom and top seal locations. the smallest spedi sleeve i can find is .472. so is this not an option, or do i need to look harder for smaller sizes?