Need help correcting a transmission leak. 97 4x4 with the 47rh trans. Rebuilt by (name with held for now). Has about 1000 miles since rebuild. transmission is leaking a lot at the seam between the main transmission case and the OD unit. All the mount bolts are tight, cooler lines & fitting are tight. Cannot find and visible cracks in the case. With the trans in N, it drips about 3 drops per second, or about a quart every 50 miles. 
Any ideas as to what would be causing the leak?? And how hard is it to fix??. Sure, it has a warrrentee, but by the time I send it back to fix it, I can do it sooner / faster myself.

Any ideas as to what would be causing the leak?? And how hard is it to fix??. Sure, it has a warrrentee, but by the time I send it back to fix it, I can do it sooner / faster myself.