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Replacing Mainshaft bearing

Discussion in 'Technical and Troubleshooting Torque' started by Viator, Nov 28, 2009.

  1. Hi all,

    I'm no mechanic, but I'm doing the best I can to fix my CBR900. I've traced an oil leak to the front sprocket so I'm pretty sure the seals around the main shaft are worn. After removal of the front sproket I've found that the leak is definately coming from around the seal, and also I can get some movement in the main shaft when I wiggle it.

    So the conclusion I'm coming to, is that I have to remove the main shaft and replace the seals and the bearing. Am I on the right track here? I'm guessing that to do this I'm going to have to drop the whole engine out of the frame somehow and then take it all appart on a bench top.

    Am I right? is there an easier way to replace this bearing? I'm a little new to this.

    Thanks in advance for your help guys.

  2. Big job unfortunately. Engine out, turn it upside down & pull the lower crankcase off to access the gearbox! Not something I would suggest unless you are very confident in your skills.
  3. I agree with 55. Don't start unless you are clear on what you are doing.
  4. Thanks for replying guys, I do appreciate it.

    I did think that I may have to pull the whole thing out but I do have the time to do it.

    I have never done anything like it before but you learn by trying right? Am I being naive or is a DIY achievable with a bit of perseverance?