You mean it's leaking from between the housing and the bearing retainer?
If so............
under that seal housing are shims, they're how you preload the front and rear pinion bearings. In a 2.5 ton, they look like this:
So, there's no gasket and you're not supposed to put sealer (like RTV) on them, although you can use that copper sealing spray on them.
I doubt any of those bolts loosened up, unless someone's been in it to replace a pinion seal. It's probably seeping past a shim(s).
You can try double checking the torque, but when that doesn't work, plan on pulling the housing off and inspecting it.