On an OMC Cobra getting a watertight seal on the U-Joint bellows is critical. If water gets in the bellows it gets onto the U-joint and the gimbal bearing. Those items can quickly rust, resulting in expensive and complex repairs. (Believe me, I know!)
The forward end of the bellows is sealed onto the round fitting on the gimbal housing using a hose clamp. You can get a good seal there as long as: 1) The lip in the bellows is properly positioned in the grove of the housing 2) The hose clamp is positioned properly in the grove of the bellows 3) The hose clamp is tightened properly and not overtightened and 4) The surface of the gimbal housing is smooth and not pitted from rust or exposure to salt water.
The seal on the aft end of the bellows is a very different mater. There is no hose clamp. The seal is created by a tight fit of the bellows into the hole in the Pivot Housing.
The OEM manual (Pivot Housing Installation, 6-24 step 9 figure 34 in my book) says : ”Apply OMC Gasket Sealing Compound around the V-shaped lip inside the U-joint bellows opening”
As the outdrive is slid into place onto the pivot housing the bearing carrier will press onto the bellows and further seal it against the pivot housing.
In my opinion, the seal between the bearing carrier and bellows is a secondary seal and should not be exposed to water as long as the other seals are intact. That includes; the forward edge of the bellows at the hose clamp, the aft end of the bellows at the pivot housing, the flat joint between the pivot housing and the outdrive and the threaded fitting for the shift cable on the back of the pivot housing.
If all those joints are water tight then there would be no water at the interface between the bellows and the bearing carrier therefore that joint is secondary.
I intend to use a sealer anyway just as more insurance for leaks and rust.
That interface was difficult because the surface of the bearing carrier was worn and pitted. I cleaned it up as best I could and filled in the rough spots with J-B Weld and then filed, sanded, used primer and painted it to get as smooth a surface as I could.
I’d like to use a sealer that will have some thickness to it and fill in any rough spots that still remained. I think that Permatex Aviation #3 will be too thin.
What gasket/ sealer would you use in this location?
The forward end of the bellows is sealed onto the round fitting on the gimbal housing using a hose clamp. You can get a good seal there as long as: 1) The lip in the bellows is properly positioned in the grove of the housing 2) The hose clamp is positioned properly in the grove of the bellows 3) The hose clamp is tightened properly and not overtightened and 4) The surface of the gimbal housing is smooth and not pitted from rust or exposure to salt water.
The seal on the aft end of the bellows is a very different mater. There is no hose clamp. The seal is created by a tight fit of the bellows into the hole in the Pivot Housing.
The OEM manual (Pivot Housing Installation, 6-24 step 9 figure 34 in my book) says : ”Apply OMC Gasket Sealing Compound around the V-shaped lip inside the U-joint bellows opening”
As the outdrive is slid into place onto the pivot housing the bearing carrier will press onto the bellows and further seal it against the pivot housing.
In my opinion, the seal between the bearing carrier and bellows is a secondary seal and should not be exposed to water as long as the other seals are intact. That includes; the forward edge of the bellows at the hose clamp, the aft end of the bellows at the pivot housing, the flat joint between the pivot housing and the outdrive and the threaded fitting for the shift cable on the back of the pivot housing.
If all those joints are water tight then there would be no water at the interface between the bellows and the bearing carrier therefore that joint is secondary.
I intend to use a sealer anyway just as more insurance for leaks and rust.
That interface was difficult because the surface of the bearing carrier was worn and pitted. I cleaned it up as best I could and filled in the rough spots with J-B Weld and then filed, sanded, used primer and painted it to get as smooth a surface as I could.
I’d like to use a sealer that will have some thickness to it and fill in any rough spots that still remained. I think that Permatex Aviation #3 will be too thin.
What gasket/ sealer would you use in this location?
