Ok I bought an nv5600 and swapped into my 08 cummins. I done reading when I first installed it and seen 5 qts so I put 6qts through the top never checked it till the other day. And it was barely under the top bolt of pto cover. But I wanted to change the oil any ways so I ordered 8 qts of pens senchromesh so I wasn't shorted any oil. Pulled the drivers side cover off and drained it and and cleaned it all out good. I went ahead and filled through the top pto cover bolt. I wasn't able to get every bit of oil out of the qts. I ended up putting all 8 qts through the Top cover bolt. I drained what was left in the other qts into one. It's about a half a qt. so I put 7.5 qts through the top pto cover bolt. Also These are stock pto covers not coolers. Should I buy more oil fill it till it comes out. Then put one more through the top. I just don't understand how so much went in the top hole when everyone else reports so much less. Thanks guys