Bah. Water in bellows.

[nola mike]

Just pulled my drive today. Plan was to swap lowers (current one has too much play in the shift shoe). I had a small amount of water in the bellows. Not sure where it's coming from. Didn't have time to investigate much. Bellows are fairly new and good shape as of last summer. U joints and gimbal bearing look good. Shift cavity didn't look wet. A couple of weird things:
1. Water looked like it was on the shaft spines. Don't know if this is from getting wet on the way out? Seems like too much water relative to the amount in the bellows. Bilge is dry.
2. O rings on the shaft were both broken.
Thoughts?
EDIT: @Bondo , meant to post in the mercruiser forum....

 

[dubs283]

Quad ring looks bulged in first pic, around the 5, 6, and 7 o clock positions.

Doesn't appear to be much water in the bellows. Perhaps condensation?

Shaft o rings aren't for sealing water or oil, they are to dampen vibration between the splined shaft and gimbal bearing. Light oil/grease at install allows them to seat properly

 

[Scott06]

Just pulled my drive today. Plan was to swap lowers (current one has too much play in the shift shoe). I had a small amount of water in the bellows. Not sure where it's coming from. Didn't have time to investigate much. Bellows are fairly new and good shape as of last summer. U joints and gimbal bearing look good. Shift cavity didn't look wet. A couple of weird things:
1. Water looked like it was on the shaft spines. Don't know if this is from getting wet on the way out? Seems like too much water relative to the amount in the bellows. Bilge is dry.
2. O rings on the shaft were both broken.
Thoughts?
EDIT: @Bondo , meant to post in the mercruiser forum....


View attachment 376541View attachment 376542View attachment 376543

I would look at the seal on the shift shaft on top of where it goes through the exhaust passage. Since the exhaust is full of water it can get up through this way. Big quad ring if not glued in can get dislodged too.

Also water in bilge if it gets to a high level can fill the bellow through the drain hole in transom housing.

The orings probably got messed up on install as mentioned they just grad the inner race of the gimbal bearing

I had the same thing one time taking off my gen one on my last boat couldn't find anything leaking but water was in bellows... put drive back on and at end of season no water was in there so never found an explanation

 

[nola mike]

Quad ring looks bulged in first pic, around the 5, 6, and 7 o clock positions.

Those are indentations from the retaining nut castellations. The perpendicular surface of the ring looks straight and even, though a bit more compressed at 7 maybe. The grease on the outdrive/bellhousing surface didn't look washed at all.

Doesn't appear to be much water in the bellows. Perhaps condensation?

Almost easier with a big leak, right? Seems like a lot of condensation, but not enough for a real leak.

Shaft o rings aren't for sealing water or oil, they are to dampen vibration between the splined shaft and gimbal bearing. Light oil/grease at install allows them to seat properly

Interesting, makes sense. They were greased on install. I'd still think they keep water from passing the gimbal bearing though, they protrude from the shaft enough that there'd be a gap if they were missing. I'm mostly concerned with the water on the shaft splines/coupler, but I can't think of a situation where water would get in there (unless the bilge is real full). Guess I'll just button her back up, run it and recheck in a few weeks. Just means I have to take the boat off the lift, pull it, etc. Couple of hours + PITA.

 

[nola mike]

I would look at the seal on the shift shaft on top of where it goes through the exhaust passage. Since the exhaust is full of water it can get up through this way. Big quad ring if not glued in can get dislodged too.

Just replied above. The shift seal/bushing isn't new, but it is the newer retrofit. Not sure how to test short of just replacing it. Quad ring was in place.

Also water in bilge if it gets to a high level can fill the bellow through the drain hole in transom housing.

Yeah, I don't think it ever got that high since last check.

The orings probably got messed up on install as mentioned they just grad the inner race of the gimbal bearing

I had the same thing one time taking off my gen one on my last boat couldn't find anything leaking but water was in bellows... put drive back on and at end of season no water was in there so never found an explanation

So unsatisfying. I won't have the patience to wait till the end of the season. Again, most concerned with the splines/coupler to see if I'm missing anything there. The ujoints are easy(ish) to replace and give you warning. Coupler, not so much.

 

[Scott06]

So unsatisfying. I won't have the patience to wait till the end of the season. Again, most concerned with the splines/coupler to see if I'm missing anything there. The ujoints are easy(ish) to replace and give you warning. Coupler, not so much.

You take your drive of every other weekend regardless if it needs it or not so no wait...

Water in coupler won't cause an issue just not supposed to be there. if there was that much grease on splines dont sweat it. If there was water no grease and you never took your drive off you may have them corrode together

 

[tank1949]

Just pulled my drive today. Plan was to swap lowers (current one has too much play in the shift shoe). I had a small amount of water in the bellows. Not sure where it's coming from. Didn't have time to investigate much. Bellows are fairly new and good shape as of last summer. U joints and gimbal bearing look good. Shift cavity didn't look wet. A couple of weird things:
1. Water looked like it was on the shaft spines. Don't know if this is from getting wet on the way out? Seems like too much water relative to the amount in the bellows. Bilge is dry.
2. O rings on the shaft were both broken.
Thoughts?
EDIT: @Bondo , meant to post in the mercruiser forum....


View attachment 376541View attachment 376542View attachment 376543

on Alphas, there is another seal on the other side of the gimbal bearing. Water can get into bellows by coming via engine hatch via gravity and landing on shaft exposed between transom and coupler. I had a bad seal one time that did this to me.

 

[nola mike]

on Alphas, there is another seal on the other side of the gimbal bearing. Water can get into bellows by coming via engine hatch via gravity and landing on shaft exposed between transom and coupler. I had a bad seal one time that did this to me.

My understanding was that this seal was to keep grease in the bearing and wasn't needed on a sealed bearing. Although I did replace the seal when I replaced the bearing a few years back. I'm still thinking it could get through that way with those broken orings though.

 

[tank1949]

My understanding was that this seal was to keep grease in the bearing and wasn't needed on a sealed bearing. Although I did replace the seal when I replaced the bearing a few years back. I'm still thinking it could get through that way with those broken orings though.

my boats all had wet decks and water is dependent on gravity!

 

[nola mike]

Update, just pulled the drive for shift cable service. Again, both shaft o-rings were broken. No water in the bellows though. FWIW, I mistakenly used an MC-1 kit (set looked identical, though different part #'s) and an el-cheapo paper gasket without the silicone beading.