How to fix the Bobbin Thread Tension on your Sewing Machine

Troubleshooting Bobbin Tension Issues with your Sewing Machine.

I don't really get tension problems when sewing stretch fabrics on my sewing machine (Brother XL-5021) but recently I've had a lot of issues when sewing woven fabrics.

Brother Sewing Machine XL-5021
My 20 Year Old Brother XL-5021

These are the steps I usually take when troubleshooting and most of the time the problem is fixed. It's important to follow the guides in your manual for your particular machine though.

  • unplug the sewing machine

  • unthread the sewing machine

  • unscrew all the removable parts, including the foot plate and brush out the lint, etc

  • apply sewing machine oil to the moving parts (consult your manual!)

  • replace the needle

  • rethread

  • test sew on scrap fabric, adjusting the top tension until the stitches are well balanced

A Makeup Brush is a Great Tool for Removing Lint
A makeup brush is a great tool for removing lint

Your sewing machine manual should tell you where to apply oil

Make sure to use Oil specifically for sewing machines
Make sure to use oil specifically for sewing machines

Recently I have found that the stitching on the underside of my sewing is loose and uneven. I thought this meant that the Upper Tension needed to be increased - however this made no difference.

Bobbin tension adjustment
This is how my bobbin threads looked before I adjusted the bobbin case screw

I did an Internet search and came across a site specialising in helping quilting and sewing enthusiasts learn more about threads, needles, notions, sewing and quilting. There are some great tips here and it's well worth taking a look. recommends adjusting the Bobbin Tension on the bobbin case. This is something that you don't usually touch so take a photograph of it in its current position incase you want to return it to its original state.

Over time, tensions can change with regular use. Even though you haven't physically changed the settings, they can work themselves either tighter or looser. Thread, lint and even temperature can affect them.

Source: Superior Threads

Bobbin case tension screw
The bobbin case screw should be adjusted in small increments only

To increase the tension in the bobbin I turned the screw, in small increments, in a clockwise direction, testing on scrap fabric after each adjustment. After a quarter turn I found that the stitches were beautifully even on the top and bottom of my fabric. This was such a relief as I was getting so frustrated with my sewing - when you go to the time and effort of making your own clothes you really want them to look professional and be well-made. Also, my machine is running beautifully now because it's also been cleaned and oiled!

If you've tried everything else and your tension is still not correct it may be worth giving this a try - but please check with your manual first!

Geordiehandbag's Sewing Adventures


Welcome to my Sewing Blog! 

My name is Joanne and I love to sew. Here I'll be sharing my hand-made makes and giving my honest opinion on pdf patterns and how easy they are to understand and construct.