Mercruiser 3.0 won't "lock in"

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,704
Thank you. I'm gonna try to tackle it myself. Looks pretty simple and straight forward.
probably won't need a gimbal puller (and I don't know that I'd replace it if it's good, though wouldn't fault you for it). with the engine out it's easy to knock out from the inside.
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
7,150
I was thinking I would go ahead and do bellows and gimbal bearing while in there. I assumed the same about the alignment, so I figure best to just knock all that out while I have the unit out. Got good numbers for those and the puller/install tool for the gimbal bearing?
I would inspect the bellows and gimbal while out before digging into it. If they are in good shape and you doo them later- the only thing you loose is pulling the drive which is a ten min job if you've done it before. Bellows and Gimbal are great projects for the off season if they are in good enough shape to last a moth or two
 

tr@v1s

Seaman Apprentice
Joined
Aug 21, 2025
Messages
48
Finally got caught up to a point I could back the pontoon up to the shop. Pulled the outdrive without and issues. Here are some pictures. Waiting on the parts to show up this week. Motor coupler obviously destroyed.

Can anyone tell me what the plate is in my hand? It obviously goes somewhere on exhaust system and was in the exhaust bellows area.

Any suggestions/things you see in the pictures I should be overly cautious of?

Is it normal to have some moisture in the shift linkage area like I do or is that an indicator I need to go ahead and change that bellow??
 

Attachments

  • 20250831_204018.jpg
    20250831_204018.jpg
    1.2 MB · Views: 15
  • 20250831_204834.jpg
    20250831_204834.jpg
    1.3 MB · Views: 15
  • 20250831_204843.jpg
    20250831_204843.jpg
    1.6 MB · Views: 14

Scott06

Admiral
Joined
Apr 20, 2014
Messages
7,150

tr@v1s

Seaman Apprentice
Joined
Aug 21, 2025
Messages
48

number 6 in the digram. As mentioned above its below the elbow in the top of the down pipe. Rubber coated metal, rubber breaks down over time and if overheated Especially. When it breaks it drops down the pipe. In theory prevents water back up into engine
Got it. So, is it really necessary or was this an 'over-engineering' thing? Had anyone ever seen the need for it in a real situation?
 

tr@v1s

Seaman Apprentice
Joined
Aug 21, 2025
Messages
48
Yes,...... back-wash can destroy a motor,......
So order a new one and get it in when I put the motor back in. Thank you. Ordering now. Can you explain how the backwask happens. Sorry if that's a stupid question. I'm just not seeing how that would happen without the motor essentially being under water since my exhaust pipe sticks up above the motor entirely before making a 180 bend back down to connect to the outdrive exhaust. Not doubting what you're saying. Just wanting to understand.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,283

tr@v1s

Seaman Apprentice
Joined
Aug 21, 2025
Messages
48
As in post 27 but using marine engine site in place of mercruiser parts site, it's items 6 and 8
https://www.marineengine.com/parts/...50801-thru-0c856558/exhaust-system-new-design

The shutters are for just in case.
You and your friends are sitting on the back of the boat and a big wave hits in the stern

Another way, your cruising along and have to stop real fast, or stop and go in reverse
Got it. Thank you!

I'm trying to find the part number for item #21 from the previous page. I got the shutter, but I can't seem to find the part number for the gasket between my exhaust manifold and the exhaust pipe.
 

tr@v1s

Seaman Apprentice
Joined
Aug 21, 2025
Messages
48
Motor coupler was pretty slick in there...
 

Attachments

  • 20250901_163655.jpg
    20250901_163655.jpg
    2 MB · Views: 8

tr@v1s

Seaman Apprentice
Joined
Aug 21, 2025
Messages
48
Glad I decided to do the impeller while I was tearing into everything. Learned how to be stupid and forget the back nut on the lower unit for a while before I finally realized why it wouldn't separate from the upper.
 

Attachments

  • 20250901_181608.jpg
    20250901_181608.jpg
    1.2 MB · Views: 5
  • 20250901_181549.jpg
    20250901_181549.jpg
    921.2 KB · Views: 5

tr@v1s

Seaman Apprentice
Joined
Aug 21, 2025
Messages
48
So...haven't checked the manuals yet, but I'm assuming I should have some oil in here...but how much?

Little bit on the floor came out when I pulled the lowere.
 

Attachments

  • 20250901_182041.jpg
    20250901_182041.jpg
    1.6 MB · Views: 12
  • 20250901_182056.jpg
    20250901_182056.jpg
    2.7 MB · Views: 11

Scott06

Admiral
Joined
Apr 20, 2014
Messages
7,150
So...haven't checked the manuals yet, but I'm assuming I should have some oil in here...but how much?

Little bit on the floor came out when I pulled the lowere.
It should be basically full to the vent plug on the side is your bellows full of oil ? Would assume your input shaft is leaking . Given the age of the drive would not be surprised if it needs all the seals .
 

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,704
It should be basically full to the vent plug on the side is your bellows full of oil ? Would assume your input shaft is leaking . Given the age of the drive would not be surprised if it needs all the seals .
So...haven't checked the manuals yet, but I'm assuming I should have some oil in here...but how much?

Little bit on the floor came out when I pulled the lowere.
Looks like you got yourself a project...
 

tr@v1s

Seaman Apprentice
Joined
Aug 21, 2025
Messages
48
It should be basically full to the vent plug on the side is your bellows full of oil ? Would assume your input shaft is leaking . Given the age of the drive would not be surprised if it needs all the seals .
The bellow wasn't full of oil. Felt/looked like some grease. Maybe I should order a rebuild kit for this thing? I'm scared to ask what all that entails...
 
Top