The stitching is a mess!?

I have Kenmore 385 16221300
I have been sewing for more years than I want to admit! I've had this machine for a few years. Recently, I broke a needle while sewing. Although I removed all pieces if the needle, I have been having trouble ever since. The Needle thread bunches up and makes large loops on the underside of the fabric. I have tried re-threading the machine MANY times, I have adjusted the top tension and even went through and cleaned all the dust collections. I just can't seem to find a solution. My bobbin just drops into place, so there is no case. I can't figure out how to try to adjust the bobbin tension...if that is the problem.
Any ideas??