Hi all. I am in the middle of a 4l60e rebuild, out of a 2002 Silverado. I did a rebuild on another vehicle 6 years ago, and it is still going strong, so I do have a small amount of experience doing this. Question is: I just completed the build up of the input drum guts and am doing the air test on the shaft to test clutch packs operations. Testing the 3-4, I am getting air blowing out of the checkball at the top of the input shaft. Is this normal? I dont remember this on the previous rebuild. Thanks for any answers.