Alpha I Gen II shift shaft seal replacement

[BillK2632]

Noticed my gear lube is getting water in it, drained some gear lube out of the bottom plug and it is definitely milky. Plan to pull the drive and pressure test to figure out what is leaking - I suspect it is the oil seal carrier (the cone thing under the water pump). When I replaced it 3yrs ago, it did not go in as tight as some others I have changed, so I have been suspect of it eversince. The other possible leak is the shift shaft seal - it is original on this 20yr old drive. I plan to go ahead and replace the oil seal carrier, shift shaft seal and the water pump since I will have things apart. Would have been doing the water pump and seal carrier anyhow at the end of this season. Hopefully it is not the propshaft seals leaking as that is probably beyond my ability.

So my question is, what is involved in replacing the shift shaft seal? Is it as simple as removing the two bolts, lifting the seal assembly out and replacing? Does the shaft just slide out/in to the new assembly? I have read where you have to be careful not to disturb anything while the shaft is out or you will not be able to get it back in.

 

[Strecker25]

Noticed my gear lube is getting water in it, drained some gear lube out of the bottom plug and it is definitely milky. Plan to pull the drive and pressure test to figure out what is leaking - I suspect it is the oil seal carrier (the cone thing under the water pump). When I replaced it 3yrs ago, it did not go in as tight as some others I have changed, so I have been suspect of it eversince. The other possible leak is the shift shaft seal - it is original on this 20yr old drive. I plan to go ahead and replace the oil seal carrier, shift shaft seal and the water pump since I will have things apart. Would have been doing the water pump and seal carrier anyhow at the end of this season. Hopefully it is not the propshaft seals leaking as that is probably beyond my ability.

So my question is, what is involved in replacing the shift shaft seal? Is it as simple as removing the two bolts, lifting the seal assembly out and replacing? Does the shaft just slide out/in to the new assembly? I have read where you have to be careful not to disturb anything while the shaft is out or you will not be able to get it back in.

put the lower on the bench upright and make sure it wont move on you, put the shift shaft in forward and simultaneously turn the propshaft by hand counterclockwise so you're sure its completely engaged. Then just pull it up slowly.

The one Oring on the bottom will probably stick in the drive so pull that out, remove the C clip that holds the shaft in the seal, and do it all in reverse.

Mine leaked so many times I actually replaced them every winter when I did impellers (cheaper than a haul out on the 290)

 

[BillK2632]

Thanks - that is basically what I have read, but good to hear from someone who has done it. Hopefully it’s that or the oil seal carrier leaking - not sure I am up to dealing with the prop shaft seal.

 

[Strecker25]

Mine would only leak when I’d put a little pressure on them emulating actually shifting. Did you pressure test the drive? Put 10psi in it and apply some lateral pressure to the shaft, you might find the leak

 

[BillK2632]

Not yet, but pressure test is my first step. Won’t be back to the lake for another week or so.

 

[BillK2632]

So finally got to this project this weekend - pulled the drive yesterday. Pressure tested and it was loosing 5lb in about 15min. A soapy solution revealed some leaking around the oil seal under the water pump (evidence of oil around the seal carrier) and the shift shaft seal, so I replaced both along with the water pump impeller. I did not see any evidence of leaking around the propshaft seal, no gear lube residue and no bubbles on the pressure test. Hopefully this takes care of it. The gear lube was milky - not terrible, but definitely had water mixing into it. I also take the time to clean everything up while the drive is apart - it's just a greasy messy job. Thanks for your advice on the shift shaft seal, it pulled right out and the new one went back in - easy peazy!

 

[Strecker25]

So finally got to this project this weekend - pulled the drive yesterday. Pressure tested and it was loosing 5lb in about 15min. A soapy solution revealed some leaking around the oil seal under the water pump (evidence of oil around the seal carrier) and the shift shaft seal, so I replaced both along with the water pump impeller. I did not see any evidence of leaking around the propshaft seal, no gear lube residue and no bubbles on the pressure test. Hopefully this takes care of it. The gear lube was milky - not terrible, but definitely had water mixing into it. I also take the time to clean everything up while the drive is apart - it's just a greasy messy job. Thanks for your advice on the shift shaft seal, it pulled right out and the new one went back in - easy peazy!

sweet! I can’t say I’ll miss the alpha service intervals now that we sold our 290. They’re good drives if maintained but I always felt our boat was too big for them. Perfect for your size boat though