My transmission is leaking and I'm having trouble figuring out where the problem is. I rebuilt the transmission with a couple new gear, synchros, seals, etc, so it's got to be something I did, or forgot to do. The gear oil is dripping out of the bellhousing when the engine is running. The transmission is in neutral. The oil level is only up to the fill hole. The oil collector is still there. None of the bolts are missing. What should I look at next?