Found this leak while changing the spin on filter. What is that little cap that appears to be leaking?
http://i47.photobucket.com/albums/f154/tommybilt/PIC-0332.jpg

That's an access hole to the torque converter area (inside the bellhousing). I would pull the cap off and check for tranny fluid in the bellhousing- if its relatively fresh, your converter and/or bellhousing bolts may be leaking. I have only done one alli build (my own), but that would be my best guess. Maybe some of the experts will chime in.

I would guess that leak to be the bolts on the housing, i just did mine in my 03. There was a recall on the two bottom bolts, all they need is two little 50 cent copper washers. but while i had mine out, i replaced the two gaskets on the case, the pump o ring, and the torque converter seal. No sense in pullin that heavy a$$ allison out twice.

I have the same issue with my '03 can you get to the bolts easily? Or does the tranny have to be dropped?

the fix is drop the tranny,replace the torque converter seal,10 pump mount bolt seals and 2 copper washers,trans should be nose up for the repair to remove and install the converter properly

I would guess that leak to be the bolts on the housing, i just did mine in my 03. There was a recall on the two bottom bolts, all they need is two little 50 cent copper washers. but while i had mine out, i replaced the two gaskets on the case, the pump o ring, and the torque converter seal. No sense in pullin that heavy a$$ allison out twice.

Did Chevy eat cost if bolt washers where recalled? My 04.5 LLY has same problem and is currently at stealer. They are suppose to call me with the damage.