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Suzuki Across scrapping/grinding noise

Discussion in 'Technical and Troubleshooting Torque' started by DamusB, Mar 23, 2015.

  1. Hi all,

    As the title says my across is making a grinding/scrapping noise. It sounds like its coming from the front sprocket but I have opened the case and even changed the sprocket and it doesn't seem to affect the noise. Chain tension is perfect and alignment is good too.
    The noise goes away when the clutch is held in for 2 seconds. Releasing the clutch a few times can make the noise go away for a while but eventually it comes back after accelerating & breaking.
    There is no power loss and the previous sprocket didn't look at all damaged so it makes me think it might be the transmission or clutch???????
    Can anyone help me isolate this issue? I am a very DIY guy and I am sure I am capable of fixing this issue with a little help.

    Thank you,

  2. Braking, you don't want to break it. ;)


    The noise is repetitive or only occurs when releasing or engaging the clutch?
    The noise changes depending on the engine revs?

    The noise exists when you fully engage the clutch and allow the revs to drop to idle when the bike is in motion?
    The noise changes based on the speed of the bike with the engine at idle and you coasting to a stop?
    • Like Like x 2
  3. question 1: only occurs when engaging the clutch.
    question 2: The noise does change depending on the engine revs.
    question 3: yes but sometimes cuts off before hand
    question 4: yes the noise does change based on the speed of the bike to some degree i think.
    Also, i find that engaging and releasing the clutch a few times can get rid of the sound for a little while but it eventually comes back with hard acceleration.

    I have done some sample recordings have watch/listen.

    the wind was a bit much so after listening back i did another recording with it in the man bag compartment.

  4. I can't hear the grinding noise but if your saying it's happening whenever you play with the clutch,and the church can quiet it down then that's where you should be looking in my opinion. Maybe pull the clutch apart and make sure everything is there and in the correct place.
  5. I worked on an across once, which had a chain like rattling / buzzing noise which occurred only once it was revved past a certain point, say 10,000rpm, and then would only go away when the revs dropped below a much lower revs, say 4000rpm. I suspected a faulty cam chain tensioner, though I can't remember what ended up happening to the bike.

    If that sounds similar to your problem, then try replacing the stock tensioner with an APE manual tensioner.
  6. your right as i have been researching this all afternoon, I have read someone had a problem with the cam chain and high revs.
    It does happen at higher revs and when I drop the revs it does eventually disappear but with that being said even at high revs if I compress the clutch about 3 times it goes away and I have to give it a certain amount of throttle to get it to come back.
    IF it was the clutch I would have thought I would have noticed some issues like slipping or something? (maybe not)
    Outside of that it kind of sounds like a bearing almost when you spin a skate board wheel too fast and it leaves you with that metal on metal sound the other thing is it sounds like its coming from the front sprocket.... the only thing is if it was a bearing at the front sprocket or something u think the noise would persist when regardless of if it was in gear or not?
    Also if it was the transmission it wouldn't be happening through all the gears.
    Its doing my head in and I dont want to bite the bullet and take it to a mechanic, I WILL FIGURE THIS OUT!
    but most likely culprits are clutch, cam chain or drive shaft bearing? if it has one.
  7. Can't pick the sound from your recording, maybe a sticking clutch spring. How many k's has the bike done?
  8. 40-41 seconds is the most prominent point in the video where u should be able to hear it. Its kind of a searing/grinding noise and is actually happening most of the video because I got it to happen as much as i could, so about 80% of the video its doing it but 40-41 is the obvious cut in and out of the noise.
    The bike just from guessing has probably done about 141 000k's as the odo is currently reading 41 000 but its one of those stupid odometers that only goes to 99 000.
  9. if you could listen from 36 seconds to 42 seconds carefully it starts at 40 and finishes at 41seconds
  11. Ok I think I hear what you mean. Lots of vibration noises can be sympathetic vibrations in something that is loose, exhaust mountings are a common culprit. I would try and determine if that is the issue.

    Does the sound appear when the bike is in neutral and you rev the engine up to cruise speed? Pull in and out the clutch.
  12. Yeah na the sound only appears when in gear and riding. Reving the engine and messing with the clutch out of gear doesn't produce the sound..
  13. listening back to the video, I actually wasnt accelerating to get the noise i was completely backed off and engine breaking which made it grind for that 1 second of time. So it seems to happen when accelerating and backing off in gear (sometimes, not all the time). There seems to be a happy point in the rev range that sets it of on a resonance level when in gear.
  14. Ok so it is unlikely to be cam chain then. This part is dangerous get the bike on its centre stand and repeat the tests with it in gear and the wheel spinning in the air. See if the sounds repeat when it is not under load.

    Of course should the back wheel touch the ground or it fall of the centre stand farcical comedy events or injury and damage could ensue. Best to do this part with two people. :)
  15. Yeah I was just having that thought.

    If it was the engine it would happen out of gear

    By process of elimination, if the clutch is active when in neutral and it doesn't make the noise when reving then its not the clutch.
    When the clutch is pulled in in it still takes about half a second to a second for the noise to stop so once again not the clutch (maybe).
    The sound is coming from the left and as far as I know the clutch is on the right of the bike??? (unsure).

    the fact it only happens when its under positive or negative load and sounds like its coming from the sprocket and sounds like a bearing metal on metal sound and happens in all gears its STRONGLY suggesting it must have something to do with the drive shaft.
    Sadly I dont have a middle stand on the across so that sucks.

    My gut feeling is I dont think it would happen if the rear wheel was in the air because I am finding that the load itself is what is initiating the issue to come and go and if I ride the bike consistently without and jolts, heavy acceleration, heavy engine break and baby it, it doesnt happen anywhere near as often.
  16. #16 wobbly sauce, Mar 23, 2015
    Last edited: Mar 24, 2015
    Heard the sound few times, also around 50-53 and some more when in your pants.
    Yes, right side for the clutch system.

    Not sure what it is though.

    Given that you said it has done about 141 000k, when was the last major service/tear down?
  17. I gave it a medium service when I bought the bike 6 weeks back which included filters, sprocket, chain lube, fluids and carby clean/work.

    But a full mechanical service jesus, would love to do it my self!
    I am starting to get used to my hands being covered the grease and oil, I think the best bet will be as cjvfr says and try replicate the noise on a stand.
    Take the fairings off and get out the stethoscope lol.
    I was really hoping it would be obvious but its clearly an unusual problem.
  18. I would find a owner operated little bike mechanic shop and get them to take it for a spin
  19. Does it happen in neutral