Replace the drive shaft seal or all in MC-1 outdrive?

gwizzar

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Took the boat out a few days ago for the first time and it ran great! This morning I noticed my lower unit is leaking oil (milky yellow color) from a small, 1/8-inch hole that I believe usually has water coming from it when I hook up the earmuffs. Did a forum search and discovered the seals/gaskets/o rings in the lower unit may need replaced, but do you think it may most likely be the drive shaft seal since the shaft bellow was recently replaced due to a tear within the old one? I have a MC-1 outdrive or pre-alpha. What exactly in regards to seals/gaskets/orings should I order if needed? My neighbor is a great mechanic and could do the work, but he works third shift and I'm just awake with my mind racing. Thx! (The pic attached is old, but red arrow shows the approximate location of the hole.)sterndrive3.jpg
 

fmalott

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

the thing to do is now pull the outdrive off and look at the drive shaft and see if the seals wore a groove in the shaft if it did you will need a new bottom end it will cost you more for a new shaft then a new bottom end been there done it. here is a picture of my I-R outdrive that the seals wore a groove on the drive shaft and was told by the very experienced people on this forum it's no good
P.S. you will see the two groove marks below the oring groove
 

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gwizzar

Petty Officer 2nd Class
Joined
Jun 7, 2012
Messages
179
Re: Replace the drive shaft seal or all in MC-1 outdrive?

the thing to do is now pull the outdrive off and look at the drive shaft and see if the seals wore a groove in the shaft if it did you will need a new bottom end it will cost you more for a new shaft then a new bottom end been there done it. here is a picture of my I-R outdrive that the seals wore a groove on the drive shaft and was told by the very experienced people on this forum it's no good
P.S. you will see the two groove marks below the oring groove

Thx! You say a new bottom end will cost less than a new shaft? Wow. Big ones to remove the outdrive from your experience?
 

fmalott

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

i priced out the drive shafts anywhere from $450 - $800 US then you have to buy the tools to do the work which is very very expensive and if you get a marina to do the job you might as well buy a whole new outdrive
 

Don S

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Before you go into a panic thinking you need a new drive, and before you start taking the drive apart, you need to remove the drive from the boat, drain the gear lube and do a pressure check of the drive and find the leak/s then determine your course of action.
You may have water in the ujoint bellows, have you had the drive off the boat when you did all the other work? If you so have water in the bellows, then you know for a fact where one leak is. The input shaft seal is not designed to keep water out, only gear lube in. The bellows is supposed to keep the water out.
 

gwizzar

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Before you go into a panic thinking you need a new drive, and before you start taking the drive apart, you need to remove the drive from the boat, drain the gear lube and do a pressure check of the drive and find the leak/s then determine your course of action.
You may have water in the ujoint bellows, have you had the drive off the boat when you did all the other work? If you so have water in the bellows, then you know for a fact where one leak is. The input shaft seal is not designed to keep water out, only gear lube in. The bellows is supposed to keep the water out.

Replaced the shift bellow due to a tear in the prior one and did not need to pull the outdrive, just pulled the shift cable out(while tied off) and replaced the bellow and then pulled the cable back through and adjusted the shift linkage.
 

gwizzar

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Jun 7, 2012
Messages
179
Re: Replace the drive shaft seal or all in MC-1 outdrive?

Before you go into a panic thinking you need a new drive, and before you start taking the drive apart, you need to remove the drive from the boat, drain the gear lube and do a pressure check of the drive and find the leak/s then determine your course of action.
You may have water in the ujoint bellows, have you had the drive off the boat when you did all the other work? If you so have water in the bellows, then you know for a fact where one leak is. The input shaft seal is not designed to keep water out, only gear lube in. The bellows is supposed to keep the water out.


Thx! been a nightmare since day 1:facepalm: Ok... thx, what is my plan of attack again based on the replacement of a shift bellow accordingly? Thx!
 

Don S

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Replaced the shift bellow due to a tear in the prior one and did not need to pull the outdrive,

See what that shortcut cost you. You was real lucky with pulling the shift cable out and not kinking it. Those cables don't last forever anyway. When you start noticing the engine dieing when going into or coming out of gear you will know where to look.
Most people end up replacing all the bellows, hoses, and shift cable after the first trip with an old boat. Want to guess why old boats are so cheap? ;)
 

gwizzar

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

:facepalm:
See what that shortcut cost you. You was real lucky with pulling the shift cable out and not kinking it. Those cables don't last forever anyway. When you start noticing the engine dieing when going into or coming out of gear you will know where to look.
Most people end up replacing all the bellows, hoses, and shift cable after the first trip with an old boat. Want to guess why old boats are so cheap? ;)

Ok..that makes me happy:) There was absolutley zero hesitation going into or coming out of gear or any other time. She was hitting straight at all times. Sounded great! "Want to guess why old boats are so cheap?" I am SO learnng, Don!:facepalm:
In addition, we were very meticulous and took our time with feeding the shift cable out and in... baby steps,,, seriously... no kinks.. I am positive.
 

Don S

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Glad everything you have done so far is working out for you.

Just remember, pulling the drive takes 10 minutes and an $8 gasket set. Then you get to check alignment, your gimbal bearing, bellows for water, GREASE THE COUPLER SPLINES (or you pull the engine to replace the coupler) lube the ujoints and look for other problems. It's a yearly maintenance job.
 

gwizzar

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Glad everything you have done so far is working out for you.

Just remember, pulling the drive takes 10 minutes and an $8 gasket set. Then you get to check alignment, your gimbal bearing, bellows for water, GREASE THE COUPLER SPLINES (or you pull the engine to replace the coupler) lube the ujoints and look for other problems. It's a yearly maintenance job.

Thx! pre-alpha gasket ordered from ??? my marine shop? or where do you recommend? A website? Annual maintenance, eh? What kind of sealer would you recommend for the housing to transom? Is there a "general" type or a specific brand you would recommend? Thx! Think I'm going to do the exhaust bellow if I'm going to pull it off. What do you think? Some people say if it looks ok, then stick with it... others say , replace all if it's been awhile and you already have the outdrive off... Your thoughts? Thx, Don. Also for moving my thread if it needed to be;)
 

Don S

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

You need to spend some time in the Adults Only sticky. Trust me. http://forums.iboats.com/showthread.php?t=288430

Especially read ALL of the How To's, they cover most of your questions. Also look at ALL of the links in the Merc info (item #10) section, and all the other stuff as well.
 

gwizzar

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

i priced out the drive shafts anywhere from $450 - $800 US then you have to buy the tools to do the work which is very very expensive and if you get a marina to do the job you might as well buy a whole new outdrive

Am I missing something? This shows a lower shaft between 26.95-42.95 and upper 39.95-49.95...
http://www.mercstuff.com/page07.htm
 
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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Am I missing something? This shows a lower shaft between 26.95-42.95 and upper 39.95-49.95...
http://www.mercstuff.com/page07.htm

Your looking at shift shafts. the drive shaft is the vertical shaft in the pic below. Look at the one on the right...See the shiny part just below the Oring at the top. That's the grove area to watch out for.
 

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gwizzar

Petty Officer 2nd Class
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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Your looking at shift shafts. the drive shaft is the vertical shaft in the pic below. Look at the one on the right...See the shiny part just below the Oring at the top. That's the grove area to watch out for.

Thx for the clarification;)
 

gwizzar

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Jun 7, 2012
Messages
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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Glad everything you have done so far is working out for you.

Just remember, pulling the drive takes 10 minutes and an $8 gasket set. Then you get to check alignment, your gimbal bearing, bellows for water, GREASE THE COUPLER SPLINES (or you pull the engine to replace the coupler) lube the ujoints and look for other problems. It's a yearly maintenance job.

Where do you recommend i purchase this gasket set? on-line? i'm pulling just the outdrive, not the housing from the transom, right? Thx!
 

boatguya1

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Your looking at shift shafts. the drive shaft is the vertical shaft in the pic below. Look at the one on the right...See the shiny part just below the Oring at the top. That's the grove area to watch out for.

I haven't been in the upper of a pre gen II alpha in a while so I could be wrong, but doesn't the upper unit on these drives seal on the part of the gear that has the ID splines those shafts go into? In other words the shiny spot you show is not where the upper unit seals in the gearlube, if I remember correctly.
 

gwizzar

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Re: Replace the drive shaft seal or all in MC-1 outdrive?

Where do you recommend i purchase this gasket set? on-line? i'm pulling just the outdrive, not the housing from the transom, right? Thx!

Right:facepalm:
 
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