{"product_id":"ohlins-seal-head-assy-14-39-21858-01","title":"Öhlins Seal head assy 14\/39 – 21858-01","description":"\u003cp\u003eSeal head assy 14\/39, Öhlins part number 21858-01. The dust seal does the hard work: it keeps the grit that would score the shaft away from the oil seal.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eInner Diameter 14 mm\u003c\/li\u003e\n\u003cli\u003eOriginal Öhlins service part\u003c\/li\u003e\n\u003cli\u003eÖhlins part number 21858-01\u003c\/li\u003e\n\u003cli\u003eOuter Diameter 39 mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eFunction\u003c\/h2\u003e\u003cp\u003eThis one measures 14 mm, 39 mm, and those figures are what separate it from the neighbouring numbers. Öhlins recommends replacing seals whenever the unit is opened, not only when it leaks. A weeping damper almost always starts here. The bushing inside carries the side load so the seal only has to seal.\u003c\/p\u003e\u003ch2\u003eGenuine Service Part\u003c\/h2\u003e\u003cp\u003eÖhlins is one of the few suspension makers that still supplies every position in the exploded view as a single part. The part number is the contract: it defines material, dimension and finish together. The exploded drawing for your unit names the number; if you do not have it, we do. The Öhlins exploded view names the number for each position; we can look it up if you do not have it.\u003c\/p\u003e\u003ch2\u003eHow to Be Sure It Fits\u003c\/h2\u003e\u003cp\u003ePart number 21858-01 is unambiguous; the description alone is not, because Öhlins uses similar wording across sizes. The published dimensions are inner diameter 14 mm, outer diameter 39 mm — measure the old part against them if you are unsure. Seals harden with heat and age even when the machine has not been ridden much. Cross-section is as important as diameter: an O-ring that is too thin will not seal at pressure.\u003c\/p\u003e\u003ch2\u003eFitting and Setup Service\u003c\/h2\u003e\u003cp\u003eFitting service parts means opening a pressurised unit. As an authorised Öhlins service centre we do that here, with the right tools and a dyno check afterwards — just ask.\u003c\/p\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cem\u003eBrand:\u003c\/em\u003e Öhlins\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003ePart Number:\u003c\/em\u003e 21858-01\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eCategory:\u003c\/em\u003e Seal Heads\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eInner Diameter:\u003c\/em\u003e 14 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eOuter Diameter:\u003c\/em\u003e 39 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cem\u003eCountry of Origin:\u003c\/em\u003e Sweden\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Öhlins","offers":[{"title":"Default Title","offer_id":53651896467722,"sku":"21858-01","price":91.76,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/21858-01_f7be406a-9c69-4b8e-81ad-e97b4f6e9baf.png?v=1788877922","url":"https:\/\/inter-pace.com\/products\/ohlins-seal-head-assy-14-39-21858-01","provider":"Inter-Pace","version":"1.0","type":"link"}