Fork bushing question ***PICS ADDED***

I replaced my fork seals Friday before the race weekend, and I'm pretty sure I should have changed the bushings, too. The manual said if any bronze/copper color shows they should be replaced. All 4 had some color coming through. It was tough to get the one leg apart even, and one bushing had a small ridge on the outside. I stupidly didn't have the parts (I didn't think they'd need replacing on a 3 month old bike, AND I had no idea how cheap they were).

Bad bushings will make it stiff, right? (I did search this topic). Forks definitely felt stiff this weekend.

Will it damage anything else using bad bushings?

And finally, can I re-use the fork seals/wipers since only 1 race?

Edit:

It's on an 07 CRF450R if that matters.

the bushings if they are hard to come out will have the coating come off them, the black stuff. If that is peeled at all, time to replace.

now if you have been running with a leaking fork seal, you could have lost enough fluid in the outer chamber to no lubricate these bushings. this is how they usually have problems. If you dont replace them worst case you could scratch the fork tube. They are like $20-30 per side for 1 inner, 1 outer bushing. Just depends on what price you get hooked up at.

If you pull the forks apart again to change the bushings, you dont have to remove the seals. So you will be fine there.

How would I change the bushings without removing the seals? Dust seal out, spring clip out, slide-hammer the tubes apart and bushings and fork seal are on the lower tube, right?

Edit:

And they were both leaking but only a little. I'd say at least 90% of the oil was still in the outer chamber.

I replaced my fork seals Friday before the race weekend, and I'm pretty sure I should have changed the bushings, too. The manual said if any bronze/copper color shows they should be replaced. All 4 had some color coming through. It was tough to get the one leg apart even, and one bushing had a small ridge on the outside. I stupidly didn't have the parts (I didn't think they'd need replacing on a 3 month old bike, AND I had no idea how cheap they were).

Bad bushings will make it stiff, right? (I did search this topic). Forks definitely felt stiff this weekend.

Will it damage anything else using bad bushings?

And finally, can I re-use the fork seals/wipers since only 1 race?

Edit:

It's on an 07 CRF450R if that matters.

Just for the record, it doesn't makes sense for the bushings to be worn out on a bike that is 3 months old.

Something doesn't right here. :thunking:

Any other clues to add?

Axel set wrong in the forks?? May also explain leaking seal?

Just for the record, it doesn't makes sense for the bushings to be worn out on a bike that is 3 months old.

Something doesn't right here. :thunking:

Any other clues to add?

It did have just under 50 hours hours it when I re-did the seals. And those are only MX hours, so the bike does get hammered pretty hard. I re-sprung for my weight at 2 hours, then had a re-valve done at 15 hours. I wouldn't have thought 30 or so hours would have have been stretching it for a fork oil change, but it did look kinda nasty, too.

This is what a worn bushing looks like, but this one was a few years old. This is extreme and seldom seen.

Bushing may also need to be replaced if they get damaged, mainly from when they are taken out of the tube, (they slam into each other which tears the Teflon).

And any metal embedded into the Teflon may warrant a replacement.

Lastly, bushings that have a lot of wear on the copper side may also need to be replaced as this usually indicates high usage and that often means that the Teflon will not be as even on the other side. This is actually more common than the Teflon wearing through.

Note that you can also see how the copper has worn on this bushing, although out of focus.

wornslider.jpg

Axel set wrong in the forks?? May also explain leaking seal?

Axle set just using procedure outlined in manual. Seal were leaking because of this race:

2009-06-20141023.jpg

Yep, that could do it.

So I plan to replace bushings before next race. I shouldn't re-use seals, right? My friend said they will very likely leak due to the slide-hammering removal of the interference fit.

Edit:

And I'll be sure to post pics of the bushings when I take them out. Thanks for the help.

Seal were leaking because of this race...

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it's no problem for a seal to wipe off the mud of the fork tube - but it's often the death for the seals when the mud dries and becomes solid rock.

it really often happens here...

Well, I pulled the forks apart as planned last night. Bushings didn't look too much different than the new ones. The oil in the left leg was black, which suprised me since I did the seals last week (4 hours ago). Oil on left is from left leg. One bushing in the right leg was damaged, and tubes were difficult to separate, but oil looked new (right in pic):

2009-07-02220749.jpg

Here is a pic of all the old bushings and seals. Left leg is on left side:

2009-07-02220736.jpg

I will probably change the oil in a couple weeks to see if it still turning black.

Damn Dude those things were hammered! When you said the oil was black you were not kidding. I've never seen fork oil like that ever, even when I did the 80 forks last year for luke.

Was the inner chamber oil black too? The showas mix oil but there is often still a difference in oil colour between inner and outer chamber.

I had the same issue with a set of Showa forks... one leg kept producing black oil after 2-3 hours, but it was definitely coming from the inner chamber... still chasing the problem but it looks like worn bushes led to a worn mv piston band and worn inner chamber. These bushes still looked OK but there was movement in this particular fork leg. The piston was rubbing hard on one side of the inner chamber and the blackness was aluminium oxide coming from the chamber wall. Now the chamber has a slightly uneven bore and i dont think these forks will ever be 100% again.

If i were you i'd replace the sliding bushes you pictures, plus for good measure replace the damper rod bush and the damper rod seal... and even think about doing the MV piston band while you're in there just to get things back to where they should be.

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