I'm fixing up a 430 to use for a loader tractor. Looking at the rear of the transmission there are 3 threaded bosses 2 look to be 1/2" and the other 3/8- 7/16. What are they used for? 2 of mine are busted out and the other has a broken off bolt in it. I looked in the tech manual and didn't see them used. Next question: upon refilling the trans, I had a bad leak at one of those bosses after looking closely, it's cracked, and can I patch it with JB Weld. Thanks