A worn or damaged bobbin case is one of the most common causes of thread tension problems and skipped stitches. Replacing it takes 5–10 minutes with no specialist tools. This guide covers Juki L-type and M-type bobbin cases across all major Juki machine series.
Always disconnect power before working near the hook area. On multi-head machines, switch off the head you are working on and engage the head-lock if available. The hook area contains fast-moving parts — safety first.
Use a Phillips or flathead screwdriver to remove the 2–4 screws securing the needle plate. Set the screws aside safely. On Juki LK series, the needle plate lifts directly after removing two front screws.
Loosen the presser foot screw and remove the foot. Remove the needle by loosening the needle clamp screw. This gives you clear access to the bobbin case and hook area.
Open the small latch on the front of the bobbin case and pull the bobbin out. Set the bobbin aside — if it still has thread, you can reuse it.
Grip the bobbin case by the latch/finger and pull it straight out of the hook basket. It should slide out with light pressure. If it resists, check that the latch is fully open. Do not force it.
With the bobbin case removed, look inside the hook basket. Check for thread tangles, lint buildup, and burrs on the hook tip. Clean with a small brush and a drop of sewing machine oil on the race track. If the hook tip has a visible nick, the hook assembly also needs replacing.
Hold the new bobbin case with the latch open and the slot aligned with the positioning finger in the hook basket. Slide it in until it clicks into place. Close the latch. Give it a gentle tug to confirm it is locked.
Drop the bobbin into the bobbin case with the thread running counterclockwise (for most Juki models). Pass the thread through the tension slot on the bobbin case. Pull a few inches of thread out through the slot.
Replace the needle, presser foot, and needle plate. Power on the machine and run a test pattern on scrap fabric. Check for consistent stitch formation, correct thread tension, and no skipped stitches.
| Juki Model | Bobbin Case Type | Notes |
|---|---|---|
| Juki LK-1900 | L type (standard) | Check sub-class for hook orientation |
| Juki TL-2010Q | L type (large) | High-capacity bobbin, check size |
| Juki MO-6814S | M type (looper thread) | Overlock — different mechanism |
| Juki HZL series | L type (standard) | Household — same replacement process |
| Juki DDL-8700 | L type (standard) | Industrial single-needle |
| Juki LBH-1790 | L type (industrial) | Buttonhole machine, check parts list |
Fix: Check the bobbin case tension spring — it should have slight resistance. Also check for burrs on the hook tip. If the hook tip is damaged, the hook assembly needs replacing too.
Fix: The positioning finger in the hook basket may be bent or worn. Inspect the finger and the slot on the bobbin case. Replace the hook assembly if the finger is damaged.
Fix: Bobbin tension too loose. Adjust the small screw on the bobbin case tension spring clockwise in very small increments (quarter turns). Test after each adjustment.
Fix: Hook timing may need adjustment after reassembly. Check that the needle plate is fully seated and the needle is at the correct height for your machine model.
L type, M type, and all Juki-compatible bobbin cases in stock. Ships worldwide via DHL in 4–7 days.
Starting from $0.9 per unit · Bulk pricing for 10+ units