How water/mud proof is a Commodore auto?

[str8up]

Hey guys, Im building a LS1 Gu with a 4L60E Auto and I would like to know how these boxes go underwater? I'm Guessing not too good? Should i seal everything up with sikaflex or something?

Cheers,

Trent

[hiy6o]

can't seal it completely but would suggest running a breather up into the engine bay somewhere and replace all the seals at input and extension housing . But auto's do run hot so if you dunk it in cold water i would say somes gunna get in , maybe see if you can increase the breather diameter so it has better flow of air when cooled quickly.

[str8up]

It's got a breather hose on it as standard so Ill run that up as high as I can. This is probably a stupid question, but how will the breather hose on top of the box stop water coming in?

[Hekta]

It's got a breather hose on it as standard so Ill run that up as high as I can. This is probably a stupid question, but how will the breather hose on top of the box stop water coming in?

You'll need to extend it and run it so it stays above water level

[PJ.zook]

It's got a breather hose on it as standard so Ill run that up as high as I can. This is probably a stupid question, but how will the breather hose on top of the box stop water coming in?

The whole point of the breather hose is to allow expansion and contraction of the air inside the box. If it didnt have a breather, when the box is hot and its suddenly cooled say by water, the air inside box contracts and will try and suck the water thru the seals.
If the box is cool and you heat it up with use, without a breather, the air would expand, and try to force oil thru the seals.