Possible shift shaft seal leak on pre-alpha mercruiser outdrive?

[auscarter12]

I have a leak in my mercruiser pre alpha outdrive. I drained the gear oil, pressure tested, changed out o-rings on the vent and drain plugs, and it still won't hold pressure. I replaced the gear oil and ran the motor last night with the hose and noticed warm exhaust water coming from where my shift shaft is. So this morning I trimmed the drive all the way up and found an oil leak, but I'm not sure if this is the shift shaft seal or what? The attached picture is with the boat in neutral. You can see blue gear oil on the left side of the shaft as well as a little water. I have never replaced a shift shaft seal or any seals on an outdrive for that matter, but I have heard that the shift shaft seal goes out a lot and is easily replaced. Can anyone give me a step by step guide on how to replace this seal, IF that is the seal leaking? Do i need to remove the lower unit from the upper? Remove the propeller? Need any special tools, etc? A step by step guide would really help. I have tried searching online to no avail. Anything will help. Thank you!

 

[fishrdan]

You don't absolutely have to remove the whole drive from the boat, but it makes the repair MUCH easier. Yes, you have to split the upper from the lower to replace the shift shaft seal.

I can't see where the fluid is leaking, but from what I see it appears as if lube is leaking from the shift shaft in the bell housing, there isn't lube in there, and if it is leaking lube from there you have the drive's input shaft seal that's bad/leaking. (PITA repair with special tools needed)

I would remove the whole drive as 1 piece, drain it and then pressure test it, using soapy water to find where it's leaking.

There should be a link to a downloadable manual up in the "Adults Only section" for your M1 drive. I can't think of any special tools needed for the shift shaft, but remove the prop before removing the drive to make the repair easier.

 

[auscarter12]

No Title

fishrdan Thank you for your advice! I have one other question. I took the boat out today and noticed quite a bit of milky oil in my bilge when I would turn my bilge pump on. I leaned behind the motor and took a picture and noticed the milky oil is seeping into the bilge between the hull and what looks like the transom plate. What could be causing this? Is it oil in the drive bellow coming from the top of the outdrive which is leaking down into the bilge?

 

[Bt Doctur]

the first pic is the shift shaft, the shift shaft bushing/seal is in the lower unit and is not visable until the unit is split.
if you see oil from above that shaft ,the bellows is filling with gear oil, this is also confirmed by seeing oil in the bilge.
Pull the drive to begin the repairs and replace the bent lower shift shoe while its apart.

 

[fishrdan]

^^^ I agree with BtDr, pull the drive as the drive's input shaft seal is leaking. You don't want ignore this repair since it can lower the lube level enough to uncover the upper gears/bearings,,, and trash your drive. $$$

That's milky drive lube being spewed out, so you have other seals leaking besides the input shaft seal... My personal take on the situation, it's time to reseal the entire drive and replace all the bellows along with an OEM original Mercruiser/Quicksilver lower shift cable. (Though, I don't know what work has been done on the boat recently either....)

 

[auscarter12]

Bt Doctur What are you referring to with the bent lower shift shoe? I've never heard or dealt with one of those. Would you happen to know a part number, perhaps?

 

[Bt Doctur]

this is a straight one

 

[auscarter12]

Are you referring to the gold colored shift shaft itself? Does that need to be replaced?

 

[Bt Doctur]

the gold colored shaft is the lower shoe, the silverish one is the upper shoe. one or both are bent.