Cat 963 Pouring oil from bell housing breather

My 963 recently started leaking a little oil from the bell housing breather. First thought was that I over filled the pump drive. Thats not the case the pump drive will maintain full and transmission will loose oil. started pouring out today, checked pump drive level and its still full transmission is bellow the add mark. any thoughts? other than that machine operates as it should breaks are laking a little. cant find anything in my books on it. Its definitely the bell housing breather and...

Cat 963 Pouring oil from bell housing breather

Cat 963 Pouring oil from bell housing breather