What is the Hole For Under the Crank Cover

[hcbx1047]

Does anybody know what the hole is for under the right crank cover? It's at the bottom and I'm scratching my head as to what it does. Is it a drain back to the crankcase?

[tevan]

I think you are correct.

[hcbx1047]

I think you are correct.

Ok, but if it is, what I can't figure out is why? The crank has a seal and if the hole drains back to the case then one would think it could also makes its way from the crankcase to the cover area. I never noticed the hole before but I just took the cover off a stored engine that had been put away with an overfilled crankcase and oil was coming out. Scratching my head on this...........and many other things lol.

[daves79x]

You are looking directly at a main bearing journal under the crank cover. Of course oil will be forced out of the bearing there and needs a place to return to the sump.

Dave

[SteveG]

Dave has it. No seal, oil coming out of bearing shell/crankshaft journal interface.

Steve

DSC02229 - Copy.JPG

[daves79x]

Thanks for the pic, Steve. It also should be noted that the top cap mounting hole is not blind and oil will seep out there if you don't have the required o-ring on the mounting screw. Most CBXs I work on now are missing those O-rings (one on each side).

Dave

[hcbx1047]

Thanks for the info! For some reason I thought there was a seal there but now I look back at the crank fiche I can't find it anymore.....