Differential Leak
 

The Passenger rear differential is leaking very bad. I dont know what exactly is leaking though. There is so much stuff going on back there that I dont even know where to start. I am putting it on the hoist soon and degreesing it and seeing where exactly but does anyone else have any pointers for me of where to look? Where it might be exactly? I left my car for a week and I came back and there was a huge puddle of differential fluid on the ground. Anything will help. Thank you! I have a 2004 Audi A4 Quattro 1.8T It has 146,000 miles. And if anyone can send me any links for parts or an exploded view of the rear differential that would be great too! Thanks again!!

Probably the seal. The part is around 20 bucks, but to get to it the rear suspension has to be unhooked.

Its the output seal. You must remove the bolt for the upper control arm. The axle bolt, and the sway bar link. That will alow enough travel to remove the axle from the hub then remove the bolts holding the axle to do the diff and remove the axle. Then remove the allen bolt in the center of the flange, and pull it out, replace the seal, reassemble.

Thanks a ton for the input! Ill be doing it soon! Thanks!!