Better yet - pop the fill plug (3/8 socket drive goes right in the plug) and simply add fluid until it starts to run out of the fill hole. That's the correct level - when fluid runs out of the fill hole with the vehicle sitting level -- so you have to put the whole car in the air, not just the front. Most autoparts places sell an inexpensive manual pump that screws to the lubricant container (check out WalMart's Marine section) - you can pump it in with that. You can also pour it in the shifter opening, but you need the fill plug out to tell when it's at the right level. And if you were leaking at the speed sensor and then it stopped, it's probaby because the fluid got low enough that it won't reach the sensor anymore - so you better get some fluid in there, and you probably ought to fix the leak.