Pinion seal has just started seeping oil

[Mile Marker 42]

2003 Monaco knight, rear pinion seal just started to leak fluid on the ground. Just a tiny bit, like a quarter size after a 750 mile trip and then sitting for 2 months at home. We are leaving on a trip and I noticed the quarter sized stain today. Only have 48,000 miles. Not something I'm interested in doing myself. I've done all the other repairs on it for 8 years. I'm going to check the breather and make sure it's clear. Any of you had this done recently, or maybe tackled it yourself? The bearing preload is something I don't have much experience with. I understand I could count the turns of the nut and match torque spec. Anyway, thanks in advance for any help.

[Skip426]

Center punch a spot on the pinion and adjoining spot on the nut ( and count the turns ) I haven't done a pinion seal on anything larger than a Dana 60 series , but I do have a 600 ft/lb torque wrench .

BTW, pinion bearing preload ; rotational drag ; is measured with the carrier and crown gear removed , pretty sure you don't want to go that far.