Upon having my motordyne XYZ pipe installed, my mechanic pointed out a leak from the drive shaft / transfer case area.

My assumption is this is fairly recent, because I had gotten an oil change done at Harte Infiniti less than 3 weeks ago, and they had done a complete inspection of the car, and they didn't mention anything.

1.) How much labor is involved to have the seal replaced? My mechanic was showing me what has to be taken apart, but I forgot to ask his estimate. So I'm just curious as to what others have paid in the past.

2.) There's no way this could have any correlation with getting my oil changed recently, could it?

 

For reference, it's a 2010 with only 30k.

 

2-3 hours labor plus part