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2006 YZ450: Rear Hub Failed

29 posts in this topic

This weekend I happened to notice that there was a slight bit of slack on my drive side rear wheel bearing. Today I took it apart and found out that the bearing is fine. The outer race is actually floating in the hub. It can spin as easily and smoothly in the hub as the inner race. Slack is minimal, you only tell by pushing on the bearing and watching a slight bit of grease ooze out between the outer race and the hub. But its definitely a problem.

Is the hub gone? Crazy to ride on it?

IF I buy a new hub do I need a new spokeset too?

Sic

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This is the second case of this I've heard of (at least I think it is).

If the bearing is loose in the hub, but the pocket is still round, you *might* have some luck using a strip of brass shim stock to line the bearing with.

An alternative would be to go to a bearing specialty house with the bearing you have and check the cross references for one on which the O.D. is slightly larger, then have the hub bored. You need to be sure there is enough material surrounding the bearing to support that solution, and that there are no cracks in the bearing boss.

If you buy a new hub on a bike no older than this, I would reuse the spokes, unless you've had it for a year and thrashed it.

The drive side bearing is different than the brake side, and also different from the drive side bearing for the '03-'05. I don't know what is different about them, but there could have been a mis-assembly issue. Better go see your dealer service manager.

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Nice job catching this! :thumbsup: Most guys would have probably rode the bike until the hub came apart destroying nuch more. The bearing should have a slight interference fit between the hub and outer bearing race, tough to measure a couple tenths but the hub should have to be heated and the bearing chilled to install it, and/or remove it.

I would get the correct bearing for that side and check the fit, if it drops in without any heat then I would say the hub is shot and should be replaced. As Grey said the spoke set should be fine for reuse. If the new bearing fits properly and you are going to reuse the hub I would clean and inspect the bearing seat very closely for cracks.

I'm going to check mine now!

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Would it be possible to post a couple of pics of this?

This is the 2 time I have heard of this and yamaha has no tech bulletins on this possible issue. :thumbsup:

How many hours are on your bike?

I would either replace the hub with new or now you have excuse to build a set of custom wheelsets

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Same exact thing happened to my 06 also. I ordered a new hub used the old spokes and nipples put in some new bearings and good as new. The question is why did the bearing spin in the race?

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That is weird. The only way I could think of that would happen is lack of grease and the bearing froze up. I just greased my rear wheel bearing when I put a new tire on last week and didn't notice anything out of the ordinary.

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The only way I could think of that would happen is lack of grease and the bearing froze up.
Or the pocket was machined too large, or the wrong bearing was installed, OR the load placed on the bearing pocket in "normal" use expanded the pocket because it was strong enough in that area.

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Has been able to save a hub by putting on some

adhesive called "bearing retainer". It fills out the "slack".

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Thanks guys for all the input !!

I decided to replace all suspect parts. I get super big discounts: for example the $135 hub was only $79 so I replaced it all: hub, 2 bearings. Total bill under $200. Also, because I'm an expert motocrosser I can't take a chance of this thing fragging on a jump face. And you know, on today's tracks it seems we are always "on a jump face".

Bike condition:

The bike is pretty cherry, never off the moto track and never pressure washed. So contaminination is a non-issue. Original bearing is mint, visible grease looks like it came right out of a new can. I looked closely for micro cracks in the aluminum hub that encirles the bearing. Saw none. At this time I suspect a manufacturing flaw. Hub ground wrong. I will look into that with Yamaha. But I will know more when I pop the bearing out. Nothing to photograph for everyone now.

Must say that comment about "bearing retainer" got me to thinking about canceling my order. But screw it. My son will inherit this bike in a month (and he's 250 expert) so I want it perfect again.

just another 56 year old motocrosser,

sic

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If the bearing is only a little loose in there, you can coat the bore of the hub with red loctite , and the outer race on the bearing. When it drys that bearing won't spin ever again. If its too loose for that, you could also use a center punch and lightly pean the bore all the way around evenly, then spread a the loctite around the bore and drive the bearing in. Of course though, the best option is to replace it.

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Or the pocket was machined too large, or the wrong bearing was installed, OR the load placed on the bearing pocket in "normal" use expanded the pocket because it was strong enough in that area.

That's true, but I would sure hope something as big as machining the hub incorrectly or installing the wrong bearing would be caught at the factory. I guess what I fear the most about that is the fact it means I could have the same problem, whereas if it were a lack of grease, I tore mine apart and lubed them. I've always wanted to learn how to lace a wheel but I want to do it because I choose to, not because my hub blew up on me...

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I think you are doing best by replacing the parts. I don't like patches or would not consider boring the hub larger for fear of weakening it in any way.

If am the guy that has to jump this thing through the air and hope that everything stays together.......I will replace the parts with new ones.

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I think your smart to replace th ehub. In the old days we used beer cans for shims. They are thin enough to work very well in this application. Sometimes it took many cans to get the perfect shim. I dont remember if it worked or not...LOL

It did work but is probably better as an on the trail fix.

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Thanks guys for all the input !!

I decided to replace all suspect parts. I get super big discounts: for example the $135 hub was only $79 so I replaced it all: hub, 2 bearings. Total bill under $200. Also, because I'm an expert motocrosser I can't take a chance of this thing fragging on a jump face. And you know, on today's tracks it seems we are always "on a jump face".

Bike condition:

The bike is pretty cherry, never off the moto track and never pressure washed. So contaminination is a non-issue. Original bearing is mint, visible grease looks like it came right out of a new can. I looked closely for micro cracks in the aluminum hub that encirles the bearing. Saw none. At this time I suspect a manufacturing flaw. Hub ground wrong. I will look into that with Yamaha. But I will know more when I pop the bearing out. Nothing to photograph for everyone now.

Must say that comment about "bearing retainer" got me to thinking about canceling my order. But screw it. My son will inherit this bike in a month (and he's 250 expert) so I want it perfect again.

just another 56 year old motocrosser,

sic

The product mentioned is loctite stud and bearing mount. It it a green anerobic compound used for things like this IN AN EMERGENCY where you have no other choice (new hub not available when you need it) You made the correct decision, if for nothing else peace of mind.

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If the chain is overly tight, is it possible to prematurely wear out the counter shaft and rear wheel drive side bearings? Also, could this cause a bearing to bind, allowing it to spin within the pocket?

I hope that the bearings, like the yz250f valves, aren't defective from the vendor.

How many hours do you have on your bike?

I guess I'll be checking my rear hub before the weekend.

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If the chain is overly tight, is it possible to prematurely wear out the counter shaft and rear wheel drive side bearings?
Yes, and or break the hub or the chain.

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This is the second case of this I've heard of (at least I think it is).

Number three ..checked mine last night, the sprocket side bearing spins pretty easily in the hub.

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