Front end rattle, Forks?

9 replies to this topic
  • sped68

Posted April 24, 2014 - 08:01 AM


Last night I changed my front wheel bearings and seals on my 06 450.  With the slop in the front wheel gone I wanted to confirm how nice and solid the front end was now, only to hear a rattling noise when I gave the front wheel a knock with my fist.  I thought at first I missed something when I put the front wheel back on but after repeatedly recreating the sound It seems to be coming from the forks.  It sounds like the spring rattling inside the forks.  I have no idea if this is normal but it doesn't seem like it would be.  Sorry if this sounds stupid but I assume when you give the front wheel a shot with your hand you shouldn't hear what sounds like the forks springs rattling.     

  • grayracer513

Posted April 24, 2014 - 08:31 AM


See if the front brake rotor has loosened over its rivets a bit.

  • sped68

Posted April 24, 2014 - 09:11 AM


It has some play but it will make the same sound with the front brake lever pulled in or if if holding onto the rotor with my other hand.  Unfortunately I've been away from the dirtbike scene for about 20 years and don't have any experience with forks like these. Could a fork tube/spring rattle if the fork is low on oil?   Is it possible to check oil level and remove the springs to check them by removing the top cap?

  • grayracer513

Posted April 24, 2014 - 09:18 AM


Not on an '06.  The springs are under the damper cartridges.  The cartridge rod has to be removed from the bottom adjuster, then the cartridge unscrewed from the top, then the cartridge and spring removed.  The springs may rattle a little. 


How much oil did you put in the outside of the fork when you went back together?

  • sped68

Posted April 24, 2014 - 09:23 AM


I have never taken the forks aprt on this bike.  When i got it last fall the previous owner said he had the bike recently serviced and the fork seals were just changed.  I have been going under the assumption everything is fine with them. 

Is it possible to but a small wire in from the top as a dipstick to check oil level or will I have to disassemble them and check?

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  • grayracer513

Posted April 24, 2014 - 09:30 AM


You have to drain and refill to check.  The oil level in the outer chambers is set by volume, not by oil height like the old fork.

  • sped68

Posted April 24, 2014 - 09:52 AM


Ok thanks.  I think it's in my best interest to pull them apart then, the rattling noise just seems excessive to me.  I can't think of anything else that could be making that noise.

  • sped68

Posted May 03, 2014 - 08:29 AM


Last night I disassembled my forks so I could look for the rattling I noticed as well as change the seals and install the bushing kit I had bought. I was kind of expecting the one fork that I heard rattling from to have a broken spring or something but it turns out that it had no oil left in it. The other fork that I knew had a bad seal was only leaking because it actually had a bit of oil left in it. Obviously the guy I bought it from that told me he just had the fork seals done was not completely honest.

So I went ahead and changed the oil in the cartridges as well as all the o rings that came in the kit. Changed bushings and seals and filled with the proper amount of oil. Needless to say the front end feels a lot more solid, no more rattling sounds, and I would guess handle a lot better than it would have before.

  • RockerYZWR

Posted May 03, 2014 - 11:48 AM


Yeah, I imagine it'll handle way better.

How much oil did you put in the outer chamber? I went with 355 cc when I had my forks apart and I don't bottom out very often (225 lbs with gear). A little bit goes a long way in these forks.

  • sped68

Posted May 03, 2014 - 05:27 PM


It was my first real ride on Wednesday and even with being away from this for about 20years I was pretty sure my forks should have performed better. In hindsight I really should have torn them apart over the winter while I looked at at sitting in the garage.
I'm probably about 225-230lbs with gear on and I took a guess with 365cc. I don't think it will be too much but it's a good starting point anyhow.

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