Shift shaft seal leak

robinsbd

Petty Officer 2nd Class
Joined
Dec 7, 2013
Messages
138
Hi All,

The marina that stores my boat in the winter, just sent me an email telling me I have shift shaft seal leak and oil dripping on the floor under the drive. They sent me an estimate for the repair dated from November. This is the first I’m hearing about this now, which I think is weird by itself, but more importantly, how does this happen? Is this a common location for a leak? When I pulled the boat in October, I didn’t notice any leaking. The oil level was correct and it looked fine in the reservoir bottle (didn’t look like any water got in). On the estimate, they are recommending a complete bellows and hoses job, gimble bearing replacement, and alignment. I just had a complete bellows service in March, 2016. My boat has been lightly used during this time.

What are your thoughts on this?
Is a complete bellows job and gimble bearing necessary for this issue? Is this the typical lifespan of the bellows? My boat sits in fresh water from May to October.

Thanks,
Brian
 

Chris51280

Master Chief Petty Officer
Joined
Jan 24, 2018
Messages
897
What outdrive do you have. The reason they suggest all the other items is because they have everything open and they don't want to be liable for putting back together the outdrive and it may be leaking then. You could say they have done it. Kinda a cover your a** kinda deal I assume.
How would they know it's the shift shaft seal? I have an alpha 1 gen one and my seal is inside between the halves. If it leaks there, I would not know since there are other potential leak areas too
 

harringtondav

Commander
Joined
May 26, 2018
Messages
2,438
A 2016 bellows job should be fine for many more years. Lube leaks from many places in, around, and under the Bell Housing end up on the floor in about the same place.

I don't know your DIY abilities, but pulling the drive yourself and pressure testing it would answer a lot of questions. From my experience the shift shaft seal is not a trouble area, but yours is getting on 22 yrs old. Changing that seal doesn't require any special tools, but you'd have to drop the lower gear hsg. to get at it. A new seal carrier assy. is relatively inexpensive and very easy to replace. Just maintain the orientation of the shift shaft foot during the repair.

Edit: The only potential show-stopper would be if the lube monitor tube in the bell hsg is leaking or damaged, causing the oil stain. I'm not taking the risk, but you might consider holding off until next season. Torque the six nuts attaching the drive to the bell hsg to 50 ft. lb. If loose this joint will leak lube. If your lube monitor reservoir doesn't drop excessively, keep on boating until it does. Then it will probably be time for a full seal job.
 
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Mad Props

Lieutenant Commander
Joined
Jul 8, 2016
Messages
1,766
Not seeing any pics.

One thing I could see "start" leaking spontaneously would be the lube monitor hose (assuming u have one) that goes from the gimbal housing to the bell housing. Its bent a pretty good amount when the drive is fully up (if it is, which it shouldn't be lol). Mine was very cracked/dry rotted when I got my boat and I've seen plenty of others that looked similar.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,092
PB wont let me edit the pic but wilh oil seepage DOWN from the shift shaft I suspect the input shaft seal my e leaking
 

robinsbd

Petty Officer 2nd Class
Joined
Dec 7, 2013
Messages
138
One of the things that irritates me is that the marina parks the boats so close to each other in the buildings that I can't lower the drive to relieve stress on the bellows in the off season. I do however keep the drive lowered while I'm in the slip.

Thank you for all of the analysis so far.

Here is what I had done in March 2016:

* Repair Kit-Transom $254.92
* Drive Install Gasket $10.20
* Trim Sender Kit $113.25
* Assy-Shift Cable Alpha $79.26

I assume the shift input shaft seal is not part of a routine bellows job. So this kind of makes sense that it would leak eventually especially if it's the original shaft seal. I'm not sure what the life expectancy on the seals, but it sounds like an age related issue. I don't typically abuse the drive, but a couple of seasons ago, I did have some carburetor idling issues, which required me to shift the drive quick and rev it up quick so it wouldn't die on me (Not fun when you're trying to dock in a slip. I had to throw it in reverse pretty hard to keep from hitting the dock).
 

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
I think that you missed Bt Doctur's point. There shouldn't be oil behind there. It goes into the exhaust passage. There isn't even a seal at that point. The seal at the top of that shaft goes into air space inside the drive shaft bellows. The input seal on the upper gear case would have to leak to get oil into the bellows.
However with the angle that the drive's on and the fact that there is a seal at the top of the shift shaft, it makes me think that the oil may be coming from the output seal on the upper gear case.
You need to get the drive off and get a better look.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
There's only one way oil can get down the upper shift shaft like that. Firstly the yoke seal in the drive shaft housing has to leak, then the big rubber seal ring in the end of the bell-housing has to leak, then the seal at the top of the upper shift shaft has to leak... One seal leaking, I'd wear that, 2 seals leaking, especially as you have the bellows done, and that includes replacing the big rubber ring, much less likely. All three of those seals leaking... I think someone's trying to drum up business during the slow part of the year!

Take the boat to an independent shop... Get it assessed....

And them saying they want to replace all the bellows, gimbal bearing and all that stuff, 'while it's apart'... Yeah, someone need winter work! I call BS....

Chris.......
 

harringtondav

Commander
Joined
May 26, 2018
Messages
2,438
I think someone's trying to drum up business during the slow part of the year!

That's been on the tip of my tongue, but I trust no shops, auto or marine. That's what got me into DIY.

I repeat, ignore them. Put it back in the water next season and watch your lube level and condition. A serious problem will show itself with a fast drop in the reservoir.
 

robinsbd

Petty Officer 2nd Class
Joined
Dec 7, 2013
Messages
138
If I put it back in the water next season as is, my concern is the possibility of getting water into the oil besides losing oil. Would that be evident in the oil monitor bottle in the engine bay? I have never had a problem like that, but my understanding is the oil would be milky and not that normal green color. It makes me uneasy to think the drive could be soaking up water in the slip while I’m at work all week. I guess not a big deal if it’s easily caught by looking at the lube monitor.

What seems strange is that I never asked for an estimate at all or any kind of assessment. I didn’t even know there was a leak until the marina sent me the estimate.

For more clarity, here is the exact description from the estimate:
“Shift shaft seal leaking drive lube externally on outdrive. Pull drive and reseal complete upper and lower. Refill with lube and remount.
Note: Suggest replacement of all hose and bellows boot kit to include new gimbal bearing. Inspect alignment and ujoints grease for additional 1000.00”
 

harringtondav

Commander
Joined
May 26, 2018
Messages
2,438
If I put it back in the water next season as is, my concern is the possibility of getting water into the oil besides losing oil. Would that be evident in the oil monitor bottle in the engine bay? I have never had a problem like that, but my understanding is the oil would be milky and not that normal green color. It makes me uneasy to think the drive could be soaking up water in the slip while I’m at work all week. I guess not a big deal if it’s easily caught by looking at the lube monitor.

The lube monitor is a closed system. It pressurizes when the drive is warm, allowing oil to push into the water through any iffy seals, then allow air through the check valve in the reservoir cap to replace lost lube when the drive cools. Except for the shift shaft, all seals are double, resisting water entry on cool down.

So your lube bottle should tell the story. The only exception is if the lube supply tube in the bell hsg is severely cracked. But the lube condition would indicate water entry.

Annual lube changes are a must and easily done Water entry will be obvious. When it appears, it time for a full seal job. When it comes time for this, pull the drive (simple job) and take it to the shop. Then inspect the rest of the gimbal assy yourself so you can specify any additional work, not the shop.
 
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