I don't have the Tin Lizzie but an HQ.
When the thread shreds it is usually because of the needle. Evidently the industry standard for quilting machine needles is that 3 out of 10 needles are defective! Only for us would that be so high.
If the thread breaks it is usualy a thread problem. I have had defective thread and returned it and the LQS confirmed it was defective thread.
It is sooo dry here that many LAer's put their thread in the refrigerator or spray mist the thread with water [just a bit and let it sit in a plastic bag or use that thread lubricant [I forget the name of that one, sorry.]
Many LAer's also use the TOWA to check the bobbin tension with each new bobbin winding. That way they only have to adjust the top tension.
Hope this helps.
ali