Threading the Kenmore 158: The Basic Path

The Kenmore Model 158 threads from the top of the machine down through a series of guides, tension discs, and the presser foot before reaching the needle. The process takes about two minutes once you know the sequence. Start with the presser foot up — this opens the tension discs so thread can pass through them — and work from the spool at the top down to the needle at the bottom, following the marked path on the machine.

The machine comes with a threading diagram printed on the inside of the presser foot cover or on the machine body itself. If your diagram is worn or missing, the path is always: spool pin, tension discs, take-up lever, upper guides, presser foot, and finally the needle. Each step matters because skipping a guide or threading the tension discs wrong will cause loops, bunching, or thread breakage.

Key Takeaways

  • Raise the presser foot before threading so the tension discs open and allow thread to pass through.
  • Follow the marked path on your machine from the spool pin down through the tension discs, take-up lever, guides, and presser foot to the needle.
  • Thread the needle from front to back, and leave a 4- to 6-inch tail hanging below the needle before you start sewing.
  • If thread keeps breaking or loops appear on the underside of fabric, the thread usually missed the tension discs or a guide — rethread from the top.

Step-by-Step Threading for the Kenmore 158

Step 1: Raise the presser foot. Lift the presser foot lever at the back of the machine all the way up. You will hear or feel a small click. This opens the tension discs inside the machine so thread can slip between them. If you thread with the presser foot down, the thread will not sit in the tension discs correctly and your stitches will be loose or uneven.

Step 2: Place thread on the spool pin. The spool pin is at the top right of the machine (or top left on some models). Slide your thread spool onto the pin so it unwinds smoothly. If the spool is too loose, it will slip; if it is too tight, the thread will not feed. The spool should turn freely when you pull thread gently.

Step 3: Thread through the tension discs. Pull the thread down and to the left (or follow the marked arrow on your machine) until it sits between the two metal tension discs. You should feel slight resistance as the thread passes between them. This is the most common place threading goes wrong — if the thread misses these discs, tension will not work and your stitches will be loose.

Step 4: Thread through the take-up lever. Continue down and thread the loop at the top center of the machine (the take-up lever). This lever moves up and down as you sew and helps control how much thread feeds into each stitch.

Step 5: Thread through the upper guides. Follow the marked path down through any remaining guides or loops on the machine body. Most Kenmore 158 machines have one or two guides between the take-up lever and the presser foot. The thread should sit in each guide, not skip over it.

Step 6: Thread through the presser foot. Pull the thread down through the slot or hole in the presser foot itself. This is straightforward to miss because it is small, but it is essential for proper tension.

Step 7: Thread the needle. Hold the thread taut and insert it into the needle eye from front to back (toward you). The needle on the Kenmore 158 is a standard sewing machine needle with a flat side facing the back of the machine. Leave 4 to 6 inches of thread hanging below the needle — do not cut it short yet.

What to Do If Threading Looks Correct but Stitches Are Wrong

If you have followed the path but your stitches are loose, bunched, or looping on the underside of the fabric, the thread usually missed one of the guides or the tension discs. The most common culprit is the tension discs — thread that looks like it is threaded but did not actually slip between them will cause loose stitches on top and tight loops underneath.

Rethread from the beginning with the presser foot up. As you pull thread through the tension discs, you should feel it catch slightly. If you feel nothing, the thread is not seated correctly. Pull it back out and try again, making sure the thread goes between both discs, not around one of them.

If stitches are still wrong after rethreading, check that your needle is inserted correctly (flat side facing back), that the needle is not bent or dull, and that you are using the right needle size for your fabric. A bent needle or one inserted backward will cause stitch problems no matter how well you thread.

Bobbin Threading and Lower Thread Path

The Kenmore 158 uses a front-loading bobbin case. Once your top thread is in place, you will need to wind and insert a bobbin with matching thread. Wind the bobbin on the spool pin by moving the bobbin winder to the right, placing an empty bobbin on the winder shaft, and running the machine. The bobbin winds automatically until it is full and stops.

Insert the wound bobbin into the bobbin case (located behind the needle plate) and pull the bobbin thread up through the slot in the case. Then pull the top thread and bobbin thread together to bring the bobbin thread to the surface. You should now have both threads ready to sew. Most tension problems come from the top thread, but if the underside of your fabric looks loose and loopy, check that the bobbin thread is also threaded correctly through its case.

Common Threading Mistakes and How to Avoid Them

Threading with the presser foot down is the most common mistake. The tension discs will not open, and thread will sit on top of them instead of between them. Always raise the presser foot first — it takes one second and prevents most threading problems.

Skipping the take-up lever is the second most common error. This small loop at the top center of the machine is straightforward to miss because it is not as obvious as the guides. If you skip it, thread tension will be wrong and stitches will be uneven. Trace the path with your finger before threading to make sure you know where every guide is.

Threading the needle from back to front instead of front to back will cause the thread to slip out of the needle as you sew. Always thread from the front (toward you) to the back. If your thread keeps falling out of the needle, this is usually why.

Using old or damaged thread can cause breakage even if threading is correct. If thread breaks repeatedly, try a fresh spool. Old thread becomes brittle and will snap under tension.

When to Call a Repair Technician

If you have rethreaded carefully, checked the needle, and used fresh thread but stitches are still wrong, the tension discs or another internal part may be damaged or out of adjustment. This is not something you can fix at home. A sewing machine repair technician can check the tension mechanism and adjust or replace parts if needed.

If the presser foot does not stay up when you lift it, or if you hear grinding or unusual sounds when the machine runs, stop using the machine and have it serviced. These are signs of mechanical problems that will get worse if you keep sewing.

Frequently Asked Questions

Do I have to raise the presser foot every time I thread?

Yes. The presser foot lever opens and closes the tension discs. With it down, thread cannot pass between the discs properly. It takes one second to raise it and prevents almost all threading problems, so make it a habit before you thread.

What if I cannot find the tension discs?

Look at the front of the machine, just below the take-up lever. You will see two metal pieces close together with a small gap between them. That gap is where the thread goes. If you are still unsure, follow the printed threading diagram on your machine — it shows exactly where they are.

Can I thread the machine while it is running?

No. Always turn the machine off before threading. Threading while the machine is running is unsafe and the needle may catch the thread and break it or the needle.

How much thread should hang below the needle before I start sewing?

Leave 4 to 6 inches. This gives the bobbin thread enough room to come up and lock with the top thread on the first stitch. If you cut the thread too short, the first stitch may not form correctly.

Why does my thread keep breaking?

Thread breaks most often because it missed the tension discs or a guide, because the needle is bent or inserted backward, or because the thread is old and brittle. Rethread with the presser foot up, check that the needle is straight and facing the right direction, and try a fresh spool of thread. If breaking continues, the tension may need adjustment by a technician.