Front Diff Boiling Oil out Dipstick

[Black98RS]

My girlfriend has a MY97 OBS that appears to be boiling gear oil out the dipstick opening of the front differential. The dipstick itself is very loose, but the diff had built up enough pressure to pop it out (I guess)and it leaked on the exhaust and smelled bad and that's how we discovered it.

We put more gear oil in it today and it took almost 1 quart to fill it, so I guess it lost about all of it because the front diff only hold 1.3 quarts anyway. It's going to the dealer tomorrow to be checked out hopefully.

My question is this: Does anyone know if maybe there is a pressure relief valve or something that maybe clogged or stuck? If the relief valve is stuck would that cause the gear oil to be boiled out of the dipstick opening? Anyone have any experience with this?

My MY98 RS had a similiar problem with the rear diff. They had to remove the cover on the back and clean out the overflow resovior because someone had overfilled it and it kept boiling gear oil out of the pressure relief hole so this is why I am assuming the front diff also has one. Anyone know how hard it is to get at?

Any info would be greatly appreciated.

Thanks,

~Brian K.