I cannot tell what the video is looking at, but, water flows down
, and could just be accumulating in the well.
I wanted to find the leak before I started tearing stuff out, so that I knew for sure what I needed to fix. If you start removing bellows to evaluate, you can no longer verify. Once you know where it's leaking, you can make better decisions about how far you have to go to fix it, or to repair transom damage.
water is likely leaking in from:
1) the exterior of the gimbal housing (which you sealed),
2) one of the 7 penetrations on the inner area of the housing,
3) from the y-pipe connection to gimbal housing (there is a gasket in that fitting) (or y-pipe rot) (This would be obvious if you ran a hose into the top of the y-pipe and plugged/covered the exhaust holes on the drive)
4) from the hydraulic trim hose manifold on the underside of the gimbal housing. (water would accumulate in the well if you lowered the boat into the water just to the point where the manifold is under water, but not low enough for the rest of the gimbal housing to be submerged).
if you can rule out the housing seal, and the Y-pipe, then it's likely a penetration. Tightening the bolts won't solve anything, and transom rot may not be the cause.
In that case, figure out which penetration is leaking. My recommendation is to wad up paper towels or tissue, around and near each interior penetration and see what gets soggy, first.
on the exterior, the gimble housing perimeter seals against the transom using a rubber seal on the inside edge. It sounds like you also sealed that perimeter with 4200, which means water shouldn't come in from the outside of the housing where it mates to the transom.
Here's a diagram to help you visualize where all the other penetrations are inside.
every penetration into the boat on the inner area of the gimbal housing has it's own seal: from top to bottom:
A) Speed hose (attaches near top onto a hose bib, and another hose on inside heading to your console) Not pictured, but mine is high up, next to #1.
1) Trim sensor and limit switch wires (penetrate through a split rubber piece), accessible from outside
2) rubber water tube (connects to a plastic tube above the upper bellow, and through a rubber grommet bolted on the inside, which connects to thermostat manifold on engine)
3) oil reservoir (if you have an gear lube monitor) hose goes to a oil fitting with o-rings, with a quick release adapter on the inside, connecting to reservoir)
4) udrive (upper below)
5) Shift cable (shift cable bellow)
6) exaust (lower bellow)
I've changed the shift bellows without removing anything, but 1, 2, and 3 would be near impossible to reach without removing 4.
I would be careful torquing down the 8 nuts on the inside of the transom bracket. These can be hard to reach and are low-torque (~22lb-ft). You don't want to crack the inner transom bracket. If you have rot, these nuts will compress your transom and still not seal properly. But, if your seal is good and the 4200 is solid, there should be no leaks from the gimbal housing, anyway.
I think you want to find the source, first. I'd rule out the upper penetrations, and see if any water collects on the inside under the drive shaft penetration, or shift cable penetration.
the lower bellows connect to the y-pipe with an rubber "o-ring", so if it's leaking in the well area,
but no where above, then it's likely the hydraulic hose manifold gasket, or y-pipe assembly/o-ring.
It's hard to get to all of that stuff, and I finally pulled the engine out to verify my leak. I took it to the water without the engine, and could immediately source the leak. At that point, I determined that it way my housing seal that was a problem, and pulled the transom bracket out to reseal it. That solved my problem, and I was able to drill easily to test the transom around the opening. If it was one of the penetrations, I would have fixed that before pulling the engine out.
