Nick60 Posted April 26, 2018 Share Posted April 26, 2018 Hi, I have dismantled the front forks to change the oil seals and got a bit of a surprise. There seems to be a double seal. The top seal came out OK ( size as expected, 31x43x12.5 ) but it sits in a steel bush which has another seal in it. I have managed to damage this. My question is, is this second seal part of the steel bush and should I be trying to remove it or do I just put a new, normal seal in? The bike is a 2K4 series ( with matching frame and engine numbers ) which I bought a few years ago from Germany. I think the forks are original but they don't match exactly any of the the picks in my Haynes manual so I'm stuck. Thanks for any help. Nick. Link to comment Share on other sites More sharing options...
jimmy Posted April 26, 2018 Share Posted April 26, 2018 Have you looked here https://www.cmsnl.com/yamaha Link to comment Share on other sites More sharing options...
Moderator Airhead Posted April 26, 2018 Moderator Share Posted April 26, 2018 are these forks the leading axle version or the ones where the axle is central to the fork leg? Link to comment Share on other sites More sharing options...
Nick60 Posted April 27, 2018 Author Share Posted April 27, 2018 Hello Airhead, thank you for your reply. The axle is central to the fork leg with a removable cap on one leg and a pinch bolt on the other. The dust cap above the seal is a metal 'press on' cap, not rubber and and there is a hard plastic spacer/ring between the oil seal and the circlip. There are no mudguard brackets on the leg. Internally, I was surprised to find no spacer above the spring but I haven't measured the spring length yet. Nick. Link to comment Share on other sites More sharing options...
Nick60 Posted April 27, 2018 Author Share Posted April 27, 2018 Thanks Jimmy, I've looked at their diagram... not my forks. Link to comment Share on other sites More sharing options...
nayruf Posted April 28, 2018 Share Posted April 28, 2018 (edited) If you cannot find the Yamaha part number or confirm the fork manufacture, Are there any identifying numbers or brand name on the seals, if there is, take a note, measure the inner diameter the outer diameter the seal height and count the number of sealing lips, normally one but can be two, then call up a seal manufacturing supplier give over the info and ask them for the best option, there is a whole industry out there that specialise in supplying seals for industrial rams of all sizes, the bonus could be that you get to find an industrial version of the seal that might be cheaper than the Yamaha or pattern supplied part http://www.athenaparts.com/eng/products/view/8419/fork-oil-seal-mgr-rsd-32x44x10-5 I think this is the part a 1981 DT 175 MX uses, the DT is listed on the, View all couplings tab, Edited April 28, 2018 by nayruf 1 Link to comment Share on other sites More sharing options...
jimmy Posted April 28, 2018 Share Posted April 28, 2018 photos would be good Link to comment Share on other sites More sharing options...
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