Front Fork Clunk

[Mississippi]

I seem to have developed a "clunk" in the front forks. It is most noticed when going over rough pavement, slow speed bumps, but can be felt at most any speed. Smooth straight pavement - not noticeable. It is a clunk felt through the handlebars when the forks compress and rebound, doesn't matter if the brakes are applied or not. Forks also feel squirrelly during sweeping turns at speed with a load on the forks. I have triple checked every bolt associated with the front forks, wheel, brake calipers, etc. Bike is an '06 with 10k miles.

I have checked the steering head bearing with the BJ wrench (thats Bike Johnny) - they were little loose, but tightening did not help problem. Also checked front wheel bearing. With wheel off the bike, the bearing feels ok, not rough, feels tight and smooth.

With the front wheel off, I can grab both lower fork housings and push/pull the forks and feel some "play". The play seems to be between the fork tube and the lower fork housing. If you place your finger where the fork tube enters the housing, you can feel the front/back play right there. The right fork definitely has more play than the left.

My problem is, I dont know how much of this play, if any, is normal. It sure doesn't feel normal. My Virago and Vmax never had any play like this.

Back in March, I hit a dog going about 80 mph about 400 miles into a SS1000. I didn't go down, the bike was fine the rest of the run. I started noticing this problem a month or two after this. It has slowly been getting worse, I cant help but wonder if this dog strike has damaged the bushings in the fork tubes. It was a pretty hard hit - cut the shepherd in half - the front wheel and forks took the entire impact.

I have a service manual and have read the procedure for disassembling the forks and am ok with it. However, it calls for a special tool to install new bushings. Has anyone ever replaced these bushings? Is this special tool neccesary or can i use something else? I have a dang shop full of tools after working on various cars and bikes for the past 35 years, and am comfortable taking the forks apart.

I would sure appreciate any advice, comments or dire warnings that anyone has - especially anything else this could be besides the fork bushings. Mucho Gracias in advance

 

[Ignacio]

Normally I'd wonder about your head bearing torque procedures...or maybe the torque of the triple clamp bolts, but if the fork itself is flexing....I'd take it to the dealer and have them do the work as a question of warranty.

 

[Mississippi]

Well....my warranty expired while I was overseas for 4 months, and even if it was still covered, I'm not sure I would take it to any dealers around here. You guys remember donaldb's episode with a local dealer last year? When they installed both of his rear brake pads on the same side of the rear rotor and trashed it? And that was the good dealer in town, I think.

Don't mean to start dealer bashing here.....but I would rather have one of our local dealers service my wife than service my bike.

I guess the point of my thread, was to try to figure out how much play I should see between the lower fork housing and the fork tube, if any. And what else inside the forks could could cause this clunking, so that I have all the proper parts on hand when I disassemble them.

Thanks for the help.

 

[kaitsdad]

Well....my warranty expired while I was overseas for 4 months, and even if it was still covered, I'm not sure I would take it to any dealers around here. You guys remember donaldb's episode with a local dealer last year? When they installed both of his rear brake pads on the same side of the rear rotor and trashed it? And that was the good dealer in town, I think.
Don't mean to start dealer bashing here.....but I would rather have one of our local dealers service my wife than service my bike.

I guess the point of my thread, was to try to figure out how much play I should see between the lower fork housing and the fork tube, if any. And what else inside the forks could could cause this clunking, so that I have all the proper parts on hand when I disassemble them.

Thanks for the help.

I just had the forks off my 06 for the second time - and there is NO play between the tube and housing. Rock solid.

My guess is you damaged something with the dog strike - and the continual stress is expanding the damage. Check the Yamaha web site for the parts fiche - it shows the forks exploded.

 

[jestal]

There is one small thing to watch for when you dissassemble the forks to find your problem..... After removing the retaining bolt from the bottom of the fork slider you have to forcibly pull the fork tube out of the slider. The tube has a bushing at the bottom end of it that will not fit thru the seal so you must pull the seal out with the fork tube. The bushing at the bottom of the slider will push against a flat washer under the seal which allows you to pull the seal out by forcibly pulling the tube out of the slider. Inspect the washer carefully after dissassembly as the force required to pull the seal out will often make the washer cone shaped. If you reassemble with the (now) cone shaped washer it will make the fork seal leak. Do not ask how I know this...... Having dissassembled my forks several times I've found that you can simply flatten the washer in a vise or you can replace if if flattening it seems too medieval.

I haven't replaced the fork bushings but they seem totally removable and replaceable without a specific Yamaha tool although you will proabably need to jerry rig some sort of specific driver. I have found that various sizes of PCV pipe and fittings aftem work well for this sort of thing...i.e..a length of 2 inch PCV pipe and a PCV reducing bushing makes an excellent fork seal driver for the FJR.

Also be aware of the loose collar on the bottom of the fork tube. When you reassemble make sure the collar is in place. It can fall off the end of the fork tube and you could mangle things by forcing the fork tube to bottom out trying to put the bolt back in at the bottom. It is not a big deal as you can shake the slider/fork tube around and feel the collar line up and fall into place should it jar loose. Just watch out for the possibility of it being out of place.

 

[Hornet Pilot]

I had a similar 'problem' and it turned out to be a fractured fork spring. It's a fairly simple procedure to check if you have a broken spring by removing each of the fork caps and then removing each spring to inspect it's length. However, mine was also identifiable by checking the front ride height and see if is lower then spec. My broken spring actually wound itself down to a lower height. That is, the top part of the broken spring wound itself down inside the lower half of the spring. this resulted in a lowering of the ride height since the front of the bike was only being supported by one spring in effect. Not sure if this your problem since it appears to be a very isolated problem but might give you some food for thought!

 

[Mississippi]

I guess I knew that there should be no play, but thanks for confirming it, it helps to know for sure.

PVC pipe....Great Idea...I kept trying to think of something that wouldn't scratch the fork tubes. The washer you spoke about is now on my list of of parts for UMotors. I'll also watch the collar at the bottom.

Broken spring...I would hate to think that I hit hard enough to break a spring...but maybe. That would sure screw up your handling. I have looked in the manual for specs on the ride height. Where did you find this?

Thanks a lot for the information and suggestions...I do appreciate it...it helps.

I missed this place the last four months

 

[Mississippi]

Pulled the forks off this morning and found the source of my problem................

The fork tubes are bent!!

If I lay a straight edge alongside the tubes, I have an 1/16" gap on the left one, and a 3/32" gap on the right one.

It is bent enough that my wife can see it without the straight edge.

I think that as the bent portion of the tube would enter the lower housing, when the fork compressed, that it put abnormal pressure on the bushings, causing them to wear and become loose.

I am not going to disassemble them further until I get new tubes and bushings on hand.

I would never have believed that the tubes would bend like that.

 

[trimmantom]

Pulled the forks off this morning and found the source of my problem................
The fork tubes are bent!!

If I lay a straight edge alongside the tubes, I have an 1/16" gap on the left one, and a 3/32" gap on the right one.

It is bent enough that my wife can see it without the straight edge.

I think that as the bent portion of the tube would enter the lower housing, when the fork compressed, that it put abnormal pressure on the bushings, causing them to wear and become loose.

I am not going to disassemble them further until I get new tubes and bushings on hand.

I would never have believed that the tubes would bend like that.

If you're having to do that you might as well replace those cheesey stock springs with some aftermarket ones like eibachs or hyperpro.

There is going to be a suspension group buy very soon.Keep a check on the group buy section for it.>

If you upgrade your suspesion you'll be glad you did.

 

[Mississippi]

I thought I would pass on something that i discovered regarding this clunking in the front forks.........

I ordered new fork parts from Umotors, the fork tubes are back ordered, don't know when I will get them - so I reassembled the forks, put in fresh PJ1 10W and installed them back on the bike so I can still ride it to work until the new parts come in.

The clunk I was experiencing is now completely gone!

I ride to work the same way everyday, and know which sections of road are going to cause the clunk to appear - but it is just not apparent anymore - the new fork fluid did the trick.

As others have reported before - the fork fluid that came out was very dark - almost black. Kind of surprising after only 13 months and 10k miles. Interestingly, the fluid that came out of the tube that was bent the most was darker than the other side. Coincidence? Maybe the bushings in that leg have worn more and deposited more particles into the oil.

I am still planning on replacing the bent tubes and bushings when the parts show up - the bike sure handles weird with the steering geometry messed up - my wheelbase is now shorter.

But to anyone who is experiencing a clunking in the front forks that is not caused by loose brake rotors or steering head bearings - consider changing your fork fluid - not that difficult and makes a world of difference.

 

[evil_henchman]

Makes sense. PJ1 "10w" is way way heavier than OEM oil (Yamaha 01 Fork Oil). You might find this interesting Link

 

[Mississippi]

That's some pretty interesting information.....I did not know that fork oils varied so much from manufacturer to manufacturer.

Lot of good info on that website....Thanks

 

[Fred W]

Don't mean to start dealer bashing here.....but I would rather have one of our local dealers service my wife than service my bike.

:rofl: :rofl: :rofl:

 

[charismaticmegafauna]

I ordered new fork parts from Umotors, the fork tubes are back ordered, don't know when I will get them -

If, for some reason, fork tubes become somewhat un-available -- you may want to try Frank's Maintenence & Engineering (Forking by Frank) in Chicago (they're often a good source for fork tubes).

 

[painman]

Maybe the group buy Warchild is sponsoring right now the guys that are doing the spring upgrades in Oregon could set you up with a set of tubes as well. Might be worth checking into and they have the right springs to upgrade the frontend while your at it. You could even ship your forks off to them and they do the work and make sure everything is in alignment. Doesn't hurt to ask. Just a thought. PM. <>< Find the thread here Group Buy and hope you get it all worked out. PM. <><

Also as a side note I just saw in the group buy thread that drew made a post and Traxxion Dynamics and CMD Computrack are just north of Atlanta. More near your neck of the woods if needed. Lots of alternatives here. I'd like to get in the group buy but right now I don't have enough money to even pay attention...PM. <><