{"product_id":"race-calibrated-servo-return-spring-kit","title":"Race-Calibrated Servo Return Spring Kit","description":"\n\u003cp class=\"sans\"\u003eOE Part No. \u003cstrong\u003e3830235, 3815914, 3830235\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cdiv class=\"spaced-vertical\"\u003e\n\u003cp\u003eMystery band failures in GM Powerglides are a common result of using inconsistent aftermarket servo return springs and weak OE springs prone to collapse. This is a problem that can be traced directly to the \u003ca href=\"http:\/\/www.sonnax.com\/tech_resources\/83-understanding-overcoming-the-powerglide-servo-pin-bias-effect-part-1\"\u003epin bias effect\u003c\/a\u003e. Sonnax race-calibrated servo return spring kit 28133-HD counteracts pin bias effect to ensure consistent servo function for longer band life and a cooler transmission. The spring's higher seat pressure helps ensure full servo release, but also features a lower spring rate to prevent excessive release force in the apply position.\u003c\/p\u003e\n\n\u003cp\u003e\u003cspan class=\"bx-pager\"\u003e\u003ca href=\"https:\/\/www.sonnax.com\/parts\/4319-race-calibrated-servo-return-spring-kit\" data-slide-index=\"1\"\u003eWatch this video\u003c\/a\u003e\u003c\/span\u003e to see exactly how an OE servo performs at high pressures when fitted with an OE, light aftermarket or Sonnax race-calibrated spring.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eSpecifically designed to work with line pressures from 200–275 psi\u003c\/li\u003e\n\u003cli\u003eIncludes two .050\" shims to aid in tuning at higher line pressures\u003c\/li\u003e\n\u003cli\u003eWorks with both OE and aftermarket servo pistons\u003c\/li\u003e\n\u003cli\u003eAlso available in Sonnax supported servo master kit \u003ca href=\"..\/i-30503440-supported-servo-master-kit.html\"\u003e28821-20K\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c\/div\u003e\n\u003cdiv class=\"part-accordion cb spaced-vertical\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u003clabel for=\"components-panel\"\u003eContents:\u003c\/label\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"accordion-content\"\u003e\n\u003cul\u003e\n\u003cli\u003eShims (2)\u003c\/li\u003e\n\u003cli\u003eSpring\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e \u003c!-- suncoast-documents:start --\u003e\u003cdiv class=\"suncoast-product-documents\"\u003e\n\u003ch3 class=\"h6\"\u003eDocuments\u003c\/h3\u003e\n\u003cul\u003e\u003cli\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0832\/4173\/0267\/files\/184473.pdf?v=1793635444\" target=\"_blank\" rel=\"noopener\"\u003eInstructions\u003c\/a\u003e\u003c\/li\u003e\u003c\/ul\u003e\n\u003c\/div\u003e\u003c!-- suncoast-documents:end --\u003e","brand":"Sonnax","offers":[{"title":"Default Title","offer_id":49129579086043,"sku":"28133-HD","price":40.2,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0832\/4173\/0267\/files\/F198656997.jpg?v=1786547485","url":"https:\/\/suncoastperformance.com\/products\/race-calibrated-servo-return-spring-kit","provider":"SunCoast Diesel","version":"1.0","type":"link"}