F150 leaking gear oil. Where do I fill?

I own a 1997 F150. I noticed the other day that my gearbox is leaking oil. I got under the truck and even looked around the top of the gearbox for a plug but did not see one. I do see two bolts that hold brackets onto the gearbox, but no plug. I am a terrible mechanic so please explain as simple as you can. Can I add 90 weight oil to this? Where do I add the oil? Thank you for helping!F150 leaking gear oil. Where do I fill?
First off, what are you calling a gearbox? If you mean the rear differential, not all of them have plugs.


Buy a Clymers manual. It will have pictures and explanations for everything.


Fix the leak. Nobody is a good mechanic until they dive in and start turning wrenches.F150 leaking gear oil. Where do I fill?
There should be a plug on the side of the gearbox and you fill to the bottom of that hole. You'll need a grease pump you can buy at the parts store. Look in Chiltons or any good auto repair manual to learn where the filler plug is. Fix the leak first.
Look for an allen type plug or a square drive plug these do not stick out as for the fluid check your owners manual for what type. Or stop in the local fast oil change shop and ask most will answer you.
there should be 2 plugs. 1 for checking and filling and 1 for draining the oil. i would say it takes 90 weight gear oil but some manuels take automatic transmission fluid.