does the final drive have any drain or fill plugs?

When I recently changed half shafts no oil came out and yet there is a seal I trust this forum to know....thanks

The differential and trans are one and share the same fluid. If you've got a trans dipstick (some do, some don't; and I can't tell you which number has what with 100% confidence), just check it hot while idling in park. Trans full=differential full. If there's not a dipstick, there's a "check plug" in the passenger side of the transaxle (10 or 11 mm plug a few inches up from the pan on the part that sticks out). You have to drive the car to get it hot, put the whole car up on jack stands (has to be level), shift through all the gears and then back to park, and then remove the plug. If you've never done this before, I'd remove the plug and let fluid run out until it slows to a trickle just incase it is overfilled. If no fluid comes out, there's a red vent/fill plug under the air filter box, add fluid there until it runs out the check plug.

Depending on the angle of the vehicle when the halfshaft is removed, sometimes you don't get fluid out even when the level is full.