150 Mercury Oil Seal Leak

[NOLA26]

I noticed a small patch of oil under my motor. I found a drip from a port behind the upper gear case oil screw. (Red Arrow). I drained the gear oil and there was about a 1/4 cup of clear water that drained out before the oil and then the oil had water in it also. The motor had only been run in a barrel of water to get it ready for the season and it wasn't put in gear.

I put the lower drain screw back in and put my air compressor nozzle with a rubber tip in the upper port. When I put in the pressurized air, I could hear hissing from the area of the gear selector (Blue Arrow). I did not hear any sound from the prop exhaust area.

What seals do I need to replace and does anyone have a part number? FYI- the entire water pump was replaced last year.

 

[The Force power]

Drop the LU and pressurize again, spray soap on shift-shaft /drive-shaft /water-pump housing & check for leaks.
most likely needs a seal-kit replacement

 

[GA_Boater]

Rotate the prop shaft, drive shaft and shift shaft while pressurize and spraying the soapy water. Sometimes seals only leak as a shaft is turned.

 

[Chris1956]

Generally that leak is from the driveshaft seal. The fix is to replace the water pump base (with it's seal), the oring and base gasket.

Second choice is the shift shaft seal.

 

[NOLA26]

Just dropped the LU and the only place I can see a leak using soapy water is on the shift shaft oil seal. The entire water pump was replaced last year. The motor is a 2002 Mercury 150XL SWB. Does anyone have a part number for the shift shaft oil seal? A video on how to replace it would be great also!

Can't find too much information about this repair online but, from what I've read, they say to not remove the shift shaft bushing. How do I get the oil seal out and the new one in without taking the bushing out?

 

[GA_Boater]

Are you sure it didn't say don't remove the shift shaft after removing the bushing? The seal is under the bushing.

 

[Chris1956]

Generally the shift shaft seals screw out. They use a spanner with two rectangular posts to turn them out. I used a punch and hammer to turn mine out. I made a spanner out of a 1/2" black pipe coupler (using a grinder) to install the new seal.

Crowleymarine will give you a part number for the seal assembly, likely
77631A2

 

[The Force power]

Generally the shift shaft seals screw out. They use a spanner with two rectangular posts to turn them out. I used a punch and hammer to turn mine out. I made a spanner out of a 1/2" black pipe coupler (using a grinder) to install the new seal.

I think we all have one of those.