{"product_id":"curt-trailer-coupler-1-7-8-in-ball-to-2-in-channel-zinc-plated-class-1-2-000-lb-lockable","title":"CURT Trailer Coupler 1-7\/8 in Ball to 2 in Channel, Zinc-Plated Class 1 2,000 lb, Lockable","description":"\u003cp\u003e\u003cstrong\u003eThe CURT K-5128 is a zinc-plated, Class 1 straight-tongue trailer coupler that secures a 1-7\/8\" trailer ball to a 2\" channel with a 2,000 lb gross trailer weight capacity and an adjustable, lockable Posi‑Lock latch.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWhen replacing a damaged coupler or building a trailer from scratch, choose hardware designed for reliable long-term performance. The CURT K-5128 couples standard 1-7\/8\" trailer balls to trailers with 2\" tongue channels and is engineered from punched, die-cut steel with a corrosion-resistant zinc finish. It combines a compact footprint with a simple, adjustable Posi‑Lock mechanism that accepts a safety pin or coupler lock for added security.\u003c\/p\u003e\n\n\u003ch3\u003eHow does the K-5128 attach to my trailer tongue and trailer ball?\u003c\/h3\u003e\n\u003cp\u003eThe K-5128 is a straight-tongue coupler built to slide over a 2\" wide trailer tongue channel and clamp solidly around a 1-7\/8\" diameter trailer ball. Installation requires aligning the coupler over the tongue channel and fastening according to the tongue’s hardware pattern, then adjusting the internal nut and spring for a snug ball fit.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMounts to 2\" tongue channel beams for a precise fit.\u003c\/li\u003e\n  \u003cli\u003eDesigned for standard 1-7\/8\" trailer balls only.\u003c\/li\u003e\n  \u003cli\u003eAdjustable nut and Posi‑Lock spring ensure tight ball engagement.\u003c\/li\u003e\n  \u003cli\u003eAccepts safety pin or coupler lock through the latch for security.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat towing limits and safety features should I expect from this coupler?\u003c\/h3\u003e\n\u003cp\u003eThis is a Class 1 coupler rated for 2,000 lb gross trailer weight (GTW) and 200 lb tongue weight (TW), intended for light-duty trailers, utility trailers, and small boat trailers. The Posi‑Lock latch delivers a positive mechanical engagement and easily accommodates a locking pin for theft prevention and vibration resistance.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e2,000 lb GTW and 200 lb TW capacity for light towing needs.\u003c\/li\u003e\n  \u003cli\u003eLockable Posi‑Lock latch helps prevent accidental uncoupling and theft.\u003c\/li\u003e\n  \u003cli\u003ePunched, die-cut steel construction for consistent strength.\u003c\/li\u003e\n  \u003cli\u003eZinc plating reduces corrosion from weather and road exposure.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I maintain and adjust the coupler for long service life?\u003c\/h3\u003e\n\u003cp\u003eMaintenance is straightforward: inspect the latch and ball seat periodically, tighten or loosen the internal adjustment nut for a secure fit, and keep moving parts clean and lightly lubricated. The zinc finish minimizes rust, but regular checks preserve smooth operation under different towing conditions.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCheck latch engagement and adjustment nut before each trip.\u003c\/li\u003e\n  \u003cli\u003eClean grit from the ball seat and apply light grease to moving parts.\u003c\/li\u003e\n  \u003cli\u003eReplace the safety pin or use a coupler lock when parked or unattended.\u003c\/li\u003e\n  \u003cli\u003eInspect for deformation or wear after heavy use or impacts.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this coupler work for boat trailers and varied weather conditions?\u003c\/h3\u003e\n\u003cp\u003eYes—its zinc-plated finish provides a durable barrier against water, salt spray, and road grime, making the K-5128 a good choice for small boat trailers and general outdoor use. Still, rinse away saltwater residue and inspect after prolonged exposure for best longevity.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eZinc plating resists corrosion from rain, snow, and road salt.\u003c\/li\u003e\n  \u003cli\u003eCompact, straight-tongue design suits small boat trailer tongues.\u003c\/li\u003e\n  \u003cli\u003eQuick-adjust Posi‑Lock mechanism keeps coupling secure under motion.\u003c\/li\u003e\n  \u003cli\u003eLimited lifetime warranty from CURT offers added buyer assurance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The CURT K-5128 is aimed at do-it-yourself trailer builders, owners replacing a worn or damaged coupler, and anyone towing light loads such as small boats, garden trailers, or utility trailers. Choose this coupler if you need a straightforward, adjustable, lockable Class 1 coupler that fits a 2\" tongue channel and a 1-7\/8\" ball, and that resists the elements with a zinc finish.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What ball size does the CURT K-5128 fit?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: It is designed to fit a standard 1-7\/8\" diameter trailer ball only.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What is the weight capacity of this coupler?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: The K-5128 is a Class 1 coupler rated for 2,000 lb gross trailer weight and 200 lb tongue weight.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"CURT","offers":[{"title":"Default Title","offer_id":48084643446942,"sku":"B0007LZGX8","price":39.48,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/curt-k-5128-front-view.jpg?v=1785861496","url":"https:\/\/northtrailauto.ca\/products\/curt-trailer-coupler-1-7-8-in-ball-to-2-in-channel-zinc-plated-class-1-2-000-lb-lockable","provider":"North Trail Auto","version":"1.0","type":"link"}