IMHO, I would say trust your gut. I can see the logic on the Jetta, but I doubt it with the weight and size of our trucks. Someone who IS running full syn may chime in on anything they might have noticed, but somehow I just don't see it.
On second thought, the synthetics should provide better...
If memory serves me right, (sometimes it doesn't) I think the manual advises to change after 500 or 5000 miles to remove break in material. After that you're good for 100K.
Here is my article on changing the rear diff fluid from the DP. CKKEVIN converted it to PDF, so thanks to him on that. If you have anything else to add for either the rear or front, fire away.
Sorry to hear man, that really sucks....Of course now would be a great opportunity to upgrade bumpers, throw in some more lighting, a winch, and you're all set....:D
Changed the oil/filter, alli spin on filter, and fuel filter today. Even had me a little help. He's only 16 months old and already wanting to turn wrenches.
http://www.dieselhaulin.com/forums/attachment.php?attachmentid=75&stc=1&d=1208492864
DSC01619.jpg...