Rear crankshaft oil seal

[solstice]

Guys I have an oil leak which appears to be from between the engine and bell housing, I’m assuming the rear crankshaft seal at the moment, I found this in an old post:

 

“In the environment of the engine running under vacuum the crank seal can be sucked in its opposite direction to normal operation and hence you can loose the seal integerity . You can just about see the seal by removing the starter motor . It would be worth trying to run it for a blat with the cam cover at atmopheric and see if that makes any difference . The crank seal giving up under vacuum is a common race series problem “

 

My car is running a vent from the dry sump oil tank but the cam cover is unvented, what are the pros / cons of venting the cam cover to see whether it resolves the leak?

Thanks

Gareth

[michaelf]

Gareth, thought mine was leaking from the oil seal.  Like F355GTS, it turned out to be the gearbox, it wasn't obviously gearbox oil because it was such a small amount everytime (and wasn't filled with Redline MTL), but enough to cover the underside from the bellhousing backwards.  Unfortunately the only way to find out for sure was to remove the engine, I just did the engine to start with but wished I'd done the gearbox/bellhousing/engine all in one go.  

[solstice]

Thanks, makes sense to do it all wHile it's out

[michaelf]

If you do remove everything, try to extract the reverse gear switch beforehand (i.e. with everything still in the car),  I broke mine taking out the gearbox and then broke a new one putting the gearbox back in , it can be removed and refitted with the gearbox in situ (in my car at least)