Original Makita coupling / clutch (part no. 313228-4) — a direct replacement coupling used in the gear housing of select Makita angle grinders. It’s the small precision coupling that transfers torque from the motor/gear train to the spindle assembly, restoring correct engagement and smooth power delivery.
Key details:
- Part number: 313228-4 (also referenced as 3132284).
- Typical fitment: used on Makita angle grinders in the GA45 / GA50 and a few related models — examples include GA4540, GA4540C, GA4541, GA5040, GA5040C, GA5041 and related variants, plus some models such as PC5010C and SA5040C as shown in exploded parts lists.
- Function / placement: installs inside the gear housing as the coupling/clutch element between gears and spindle to ensure correct engagement under load.
- Compatibility note: these grinders use a 5/8"-11 spindle interface (≈15.88 mm thread), and this coupling is the factory replacement specified for the GA45/GA50 SJS‑series grinders.
Why this part matters: if your grinder shows slipping, noisy gear engagement, or won’t reliably drive the wheel, replacing the worn coupling/clutch with this original Makita part restores the intended fit and torque transfer without modifying the tool. The part is a straightforward swap into the gear housing using the standard fasteners.
What you get: one genuine Makita 313228-4 coupling/clutch, ready to install into the models listed above.
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