I had one go out a couple months ago. $126 is reasonable. I did mine at home but $126 makes it a toss up... and mine was fairly easy.If you have ever replaced one, you will quickly realize that might be the best $126 you ever spent, especially on an 03 that is probably rusted in. Send Rbattle a note and ask him if he would have spent $126 to have it done.
Cattletrkr I am not sure about yours If you have the NV5600 with the 4X4... . If you are talking about the output shaft seal on the trans where it connects to the transfer case, its a real pain. You will have to remove the transfter case and pull the tail housing off of the trans. But it can all be done in chassis. but that is for the cast iron nv5600 I think the 04 has the alluminum g56. That one I am not sure about.