Threading the Kenmore 158: The Basic Path
Threading a Kenmore 158 follows the same logic as most machines: you guide thread from the spool down through a series of guides and tension discs, then through the needle. The Kenmore 158 has a straightforward path that takes about two minutes once you know where each part sits. The thread must pass through the presser foot lever before it reaches the needle — this is the step most people skip, and it causes tension problems when ready.
Start with the presser foot lever in the up position. This opens the tension discs so thread can pass between them. If the lever is down, the discs clamp shut and thread cannot seat properly, which is why your machine will skip stitches or break thread even though you threaded it "correctly."
Key Takeaways
- The presser foot lever must be up before you thread; this opens the tension discs and lets thread pass through them.
- Thread goes from the spool pin, through the guide above the bobbin area, through the tension discs, through the take-up lever, and finally through the needle.
- The take-up lever — the small metal arm that moves up and down — must have thread seated in its hook before you thread the needle.
- After threading the needle, lower the presser foot lever to close the tension discs and lock the thread in place.
Step-by-Step Threading for the Kenmore 158
Place your spool of thread on the spool pin at the top right of the machine. The spool pin is a small metal rod that sticks up; thread slides onto it with the spool sitting flat against the machine body. If your thread is thin or slippery, use a spool cap — a small plastic disc that comes with the machine — to hold the spool in place.
Pull thread from the spool and guide it down and to the left into the thread guide, a small metal loop or hook above the bobbin area. This is your first checkpoint. Thread should sit snugly in this guide; if it slips out, it will not tension correctly.
From the thread guide, pull thread down between the two metal discs that make up the tension assembly. These discs look like a narrow slot. Push thread straight down into the slot until you feel slight resistance — that resistance means thread is seated between the discs. This is critical. If thread only rests on top of the discs instead of between them, tension will be loose and stitches will be uneven.
Continue upward and to the right to the take-up lever, a small metal arm that sticks out from the machine body. Thread must pass through the hook or eye at the end of this lever. This lever moves up and down as you sew; it helps regulate how much thread feeds into each stitch. If thread misses this lever, the machine cannot form proper stitches.
From the take-up lever, guide thread down and through the needle threader (if your machine has one) or directly into the needle eye from front to back. The needle should be in the highest position — turn the handwheel toward you until the needle bar rises all the way up. Thread the needle from the front, and leave a tail of thread hanging below the needle about 4 to 6 inches long.
Finally, lower the presser foot lever. This closes the tension discs and locks thread in place. You are now ready to wind a bobbin and begin sewing.
What to Do If Thread Keeps Breaking or Skipping
If thread breaks during sewing or stitches skip, the first thing to check is whether the presser foot lever is down. A surprising number of tension problems come from the lever being slightly up, which leaves the discs partially open. Lower it fully and try sewing again.
The second check is the tension discs themselves. Rethread the machine, and as you pull thread through the tension slot, make sure it goes between the discs, not around them. You should feel the discs grip the thread slightly. If thread slides through without any resistance, it is not seated correctly — pull it out and try again, pushing it straight down into the slot.
If thread still breaks after the presser foot is down and thread is seated in the discs, check the needle. A bent or dull needle will catch thread and break it. Replace the needle with a fresh one, rethread, and test. Most thread breakage on the Kenmore 158 comes from a bent needle or thread that missed the tension discs.
Threading the Bobbin and Lower Thread Path
The bobbin — the small spool that holds thread underneath the needle — has its own threading path. Wind thread onto an empty bobbin using the bobbin winder on the side of the machine, then insert the bobbin into the bobbin case below the needle plate.
To thread the bobbin case, pull the bobbin thread up through the slot in the bobbin case cover, then under the tension spring (a small metal wire that holds the thread). The bobbin thread should sit under this spring; if it rests on top, tension will be wrong and stitches will be loose. Once the thread is under the spring, pull it to the side and cut it short. You are ready to sew.
Common Mistakes to Avoid
The most common mistake is threading with the presser foot lever down. This clamps the tension discs shut, and thread cannot pass between them. Always raise the lever before you thread.
The second mistake is skipping the take-up lever. Thread must pass through this small metal arm; if it misses, the machine will not form proper stitches and thread may break. Trace the path with your finger before you sew to make sure thread touches every guide and lever.
A third mistake is using a needle that is bent, dull, or inserted backward. The Kenmore 158 uses needles with a flat side on the back. Insert the needle so the flat side faces the correct direction for your machine (check your manual for which way), and make sure the needle is pushed all the way up into the needle clamp. A needle that is even slightly loose will cause skipped stitches.
When to Rethread and When to Check Something Else
Rethread the machine if stitches suddenly become loose, uneven, or if thread breaks. Also rethread if you change thread color or weight, because different threads may need slightly different tension settings, and rethreading ensures thread is seated correctly in the discs.
Do not rethread if the problem is only on the underside of the fabric (where the bobbin thread shows). In that case, the issue is usually bobbin tension, not upper thread tension. Check that the bobbin thread is under the tension spring in the bobbin case, and make sure the bobbin itself is wound evenly and inserted correctly.
Frequently Asked Questions
Do I have to raise the presser foot lever every time I thread?
Yes. The lever opens and closes the tension discs. If the lever is down, the discs are clamped shut and thread cannot pass between them. Raise the lever before threading, and lower it after the needle is threaded to lock everything in place.
What if I cannot see the take-up lever?
The take-up lever is a small metal arm on the front or side of the machine body, usually to the right of the needle. It moves up and down as the machine runs. If you cannot locate it, check your Kenmore 158 manual — it will have a diagram showing every part. Thread must pass through the hook or eye at the end of this lever.
Can I thread the machine with the needle down?
No. Always raise the needle to its highest position before threading. Turn the handwheel toward you until the needle bar rises all the way up. This makes it easier to see the needle eye and ensures the needle is in the correct position for threading.
What does it mean if thread is not seated in the tension discs?
If thread rests on top of the discs instead of between them, the discs cannot grip the thread and control tension. This causes loose, uneven stitches. Pull the thread out and rethread it, pushing straight down into the slot between the discs until you feel resistance.
Why does my thread keep breaking even after I rethread?
Check the needle first. A bent or dull needle will catch and break thread. Replace it with a fresh needle, rethread the machine, and test. If thread still breaks, make sure the presser foot lever is fully down and thread is seated between the tension discs. Also check that you are using the correct needle size for your fabric and thread weight.