BMW Service Bulletin Archive

improved-fork-seals-31-021-88-2320-888

( { ‘ ‘, Service-InformationM otorcycle BMW. NAยท Service Department : ‘.- -โ€ข –โ€ขโ€ข ‘::โ€ข_ยท:\;;:!~~1t.>)Tยท?rยท:,:ยท~~:’ ::’;.~r)rT: ~s1!r~t;)JI}?II~ ~If :T_ยท,1 Impro_!ed>Eยท ;k: Seals – R80 and, _Rl,~~:,~~~ls- ยท ~~~ ~nยทยท __,- .>ยท .;::_,;., _ _ 0:;\::, —-~ Problem: Infonnation: Fork Seal Replacement: SHARP EDGE Leaking Fork Seals As described in Service Information 31 019 88 (2279) titled: “Improved Fork Seals – KlOO and K75 models 11 the Boxer models are now also produced with a Fork Seal which has an additional dust lip. In addition to the improved Fork Seal, the new rubber dust covers also have a sharp scraper edge. Proceed as described in Service Information 31 019 99 (2279) for the K models. 1. Use a rubber Dust Cover with a sharp scraper edge. The improved Dust Cover has a scraper with squared edge (approximately 90ยฐ). The older style Dust Cover has a s1 i ghtly rounded scraper edge (approximately 80ยฐ). It is difficult to visibly notice the difference. Ensure that only the improved Dust Cover is used. New Dust Cover 80ยฐ EDGE Part No. 31 42 1 454 392 2. An improved, dual-lip Fork Sec:1 with an extra scraper lip is available under: Part No. 31 42 2 310 199 To ensure that the Fork Seal Is scraper 1 i p does not contact the Dust Cover, a Spacer Ring must be placed on top of the Fork Seal. Part No. 31 42 1 458 474 Note: Unpainted Area Motorcycles now in Production: Important: Very truly yours, The improved rubber Dust Covers are s1 ightly shorter than the earlier type. This will leave al .l mm wide unpainted band under the Dust Covers. This unpainted band can be covered with frame paint – Part Number 51 91 1 453 483 to match the black slider. Grease Packing – Shell Retinax A 81 22 9 407 303 VA,,i;:..–::::;,::::- Qust Boot “~,.._- 31 42 l 454 392 Spacer Ring 31 42 l 458 474 Fork Seal with Oust Lip 31 42 2 310 199 On motorcycles now in production, the slider tube is machined to a sufficient depth to prevent the fork seal (when fully pressed in) from touching the dust cover. The snap ring used on K models is not used on R models. Whenever the fork tubes are taken apart, clean the dust covers and check them by slipping them over the fork tube and ensure that they are tight (without clearance} and that the scraper edges are straight and sharp. Before mounting the dust covers, fill the grease pockets with: Shell Retinax A – Part No. 81 22 9 407 303 – 150 gr BMWO F NORTAHM ERICAIN, C. ~&rLL/t) Frank Stevens Rj cha :-d Dampf National Service Manager National Technical Manager jel/975.4 ( ( lj

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