To check diff oil level in my 99, the plug is behind (above) the pendulum mount.? Easiest to remove the pendulum mount to check and add, but it can be done by not removing it if you have enough extensions to wrench from behind the subframe.? I have not seen a way to drain the differential?? Someone please chime in if you know the secret, other than suction out and replace.? I'd like to drain mine.