{"product_id":"mercury-mercruiser-roller-bearing-coupling-shim-set-39899a1","title":"Mercury MerCruiser 39899A1 Roller Bearing-to-Coupling Shim Set – TR \/ TRS Drive","description":"\u003csection class=\"product-description\"\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eMercury MerCruiser 39899A1\u003c\/strong\u003e is a genuine OEM \u003cstrong\u003eroller bearing-to-coupling shim set\u003c\/strong\u003e used to establish the correct internal spacing in selected MerCruiser TR and TRS sterndrive assemblies. The set contains four shim thicknesses — \u003cstrong\u003e.002, .003, .005, and .010 in.\u003c\/strong\u003e (approx. 0.051, 0.076, 0.127, and 0.254 mm) — allowing the correct stack to be selected during assembly. The original 39899A1 has been superseded by current Mercury shim set \u003cstrong\u003e36178A02\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eCompatible Applications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMerCruiser 255 TRS\u003c\/strong\u003e — 1973–1974\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMerCruiser 280 TRS\u003c\/strong\u003e — 1975–1976\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMerCruiser II-TR\u003c\/strong\u003e — 1973–1976\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMerCruiser TR \/ TRS\u003c\/strong\u003e — 1977–1993\u003c\/li\u003e\n\u003cli\u003eSelected \u003cstrong\u003e215E \/ 215H\u003c\/strong\u003e applications — verify by drive serial number and parts diagram\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eAlways confirm fitment using the sterndrive model, serial number, and the applicable Mercury parts diagram before ordering.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch2\u003eWhere It Fits – Assembly Position\u003c\/h2\u003e\n\u003cp\u003eIn TR\/TRS drive-shaft-housing diagrams, this shim set is positioned between the \u003cstrong\u003eroller bearing and coupling assembly\u003c\/strong\u003e. The correct shim stack is determined by measurement during the rebuild — it is not a fixed value that can be carried over from one service to the next without verification.\u003c\/p\u003e\n\n\u003ch2\u003eKit Contents – Shim Thicknesses\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e.002 in. (approx. 0.051 mm)\u003c\/li\u003e\n\u003cli\u003e.003 in. (approx. 0.076 mm)\u003c\/li\u003e\n\u003cli\u003e.005 in. (approx. 0.127 mm)\u003c\/li\u003e\n\u003cli\u003e.010 in. (approx. 0.254 mm)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOriginal OEM Part Number:\u003c\/strong\u003e 39899A1 \/ 15-39899A1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSuperseded By:\u003c\/strong\u003e 36178A02 \/ 15-36178A02\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntermediate Reference:\u003c\/strong\u003e 36178A1 \/ 15-36178A1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEarlier Related Reference:\u003c\/strong\u003e 23097A1 \/ 15-23097A1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGTIN:\u003c\/strong\u003e 745061141643\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFactory Description:\u003c\/strong\u003e Shim Set – Roller Bearing to Coupling\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSystem:\u003c\/strong\u003e Sterndrive drive-shaft housing \/ gear and bearing assembly\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eFitment Notice – Precision Setup Component\u003c\/h2\u003e\n\u003cp\u003eThis is a \u003cstrong\u003eprecision setup part\u003c\/strong\u003e, not a universal spacer. The correct shim stack must be determined using the applicable Mercury service procedure for the exact drive assembly being rebuilt. Do not reinstall the same shim thickness without verifying the bearing-to-coupling setup, especially if bearings, gears, shafts, or housings have been replaced — any of those changes can alter the required shim selection.\u003c\/p\u003e\n\n\u003ch2\u003eWhen to Replace\u003c\/h2\u003e\n\u003cp\u003eReplace or reselect the shim set when:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eRebuilding the applicable drive-shaft or gear assembly\u003c\/li\u003e\n\u003cli\u003eReplacing the roller bearing or coupling\u003c\/li\u003e\n\u003cli\u003eBearing preload or internal spacing is being reset\u003c\/li\u003e\n\u003cli\u003eThe original shims are bent, damaged, corroded, or missing\u003c\/li\u003e\n\u003cli\u003eService measurements indicate a different shim stack is required\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cp\u003eCorrect installation requires measurement and setup per the Mercury service manual:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eKeep all shims clean and flat — do not reuse distorted shims\u003c\/li\u003e\n\u003cli\u003eMeasure the required stack thickness according to the Mercury service procedure for this drive\u003c\/li\u003e\n\u003cli\u003eConfirm bearing and coupling condition before final assembly\u003c\/li\u003e\n\u003cli\u003eUse only the thickness combination needed to achieve the specified setup\u003c\/li\u003e\n\u003cli\u003eRecheck bearing preload and endplay where required before closing the housing\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAlternate \/ Superseded Part Numbers\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e39899A1 \/ 15-39899A1 — original Mercury number\u003c\/li\u003e\n\u003cli\u003e36178A1 \/ 15-36178A1 — intermediate replacement\u003c\/li\u003e\n\u003cli\u003e36178A02 \/ 15-36178A02 — current replacement\u003c\/li\u003e\n\u003cli\u003e23097A1 \/ 15-23097A1 — earlier related reference\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eRelated Parts\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/8131405283364\"\u003eMercury MerCruiser Quicksilver Driveshaft Locknut 41527T\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/8131403546660\"\u003eMercury MerCruiser Driveshaft Housing Water Seal 36557\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/8131412197412\"\u003eMercury Quicksilver Driveshaft Housing Plug 64649\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/8131400302628\"\u003eMercury MerCruiser Quicksilver Driveshaft Slinger Ring 30271 — 8M0214918\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eParts Desk Insights\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eBest Use Case:\u003c\/strong\u003e This shim set is the right call during a full TR or TRS drive rebuild — specifically when the roller bearing or coupling is being replaced and the internal spacing needs to be re-established from scratch. It’s a measurement-driven setup step, so having the full range of shim thicknesses in hand before starting the job is the smart way to work.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon Issues:\u003c\/strong\u003e The most frequent mistake is assuming the original shim stack can be reinstalled without re-measuring. Any time a bearing, coupling, shaft, or housing is replaced in this assembly, the required shim thickness can change — carrying over the old stack without checking can result in incorrect bearing preload and premature drive failure. Always measure first, then select the correct combination from the set.\u003c\/p\u003e\n\n\u003c\/section\u003e","brand":"MERC","offers":[{"title":"Default Title","offer_id":43563857018916,"sku":"39899A1","price":21.19,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/534c19f4-7f45-41c7-bc95-9dec1095e536.png?v=1776286724","url":"https:\/\/marisolmarine.com\/products\/mercury-mercruiser-roller-bearing-coupling-shim-set-39899a1","provider":"Marisol Marine Company","version":"1.0","type":"link"}