Swingarm linkage rebuild

[Goosedog]

Wouldn't you know that as soon as my bike gets a fresh top-end I notice the swingarm linkage is in need of rebuilding. When I lifted the back of the bike yesterday, the rear wheel drops a 1/4in. or so with a clunk.

I seem to remember a post awhile back that had a link to some very well laid out pics and discription for re-packing the needle bearings in the swingarm (I think it was in the YZ250F forum pages). Can someone post that for me if they have it?

Also, is there any up-grades that can be done while I've got this part of the bike torn down so as to improve or increase the time between services of these bearings. Thanks

[Ga426owner]

I am not sure of the hrs on the linkage...but the clunk is usually the Shock bearings...they go much quicker than the linkagebearings...

[Goosedog]

I am not sure of the hrs on the linkage...but the clunk is usually the Shock bearings...they go much quicker than the linkagebearings...

Hmmm, well that makes sense then cause I did repack the linkage bearings when I first got the bike, I had just forgotten the procedure and wanted to see the instructions again.

I'm due for a suspension overhaul and need every thing re-valved and re-built anyway. Are stock shock bearings normally something that would be re-placed (doing a re-valve) with aftermarket parts or should I get the OEM stuff on the way.

[Ga426owner]

Hmmm, well that makes sense then cause I did repack the linkage bearings when I first got the bike, I had just forgotten the procedure and wanted to see the instructions again.

I'm due for a suspension overhaul and need every thing re-valved and re-built anyway. Are stock shock bearings normally something that would be re-placed (doing a re-valve) with aftermarket parts or should I get the OEM stuff on the way.

OEM and Pivotworks make the complete linkagekits...the Shock bearing kit I believe is separate/you replace it...do it all together.

[grayracer513]

I seem to remember a post awhile back that had a link to some very well laid out pics and discription for re-packing the needle bearings in the swingarm (I think it was in the YZ250F forum pages). Can someone post that for me if they have it?

http://www.thumperfaq.com/swingarm.htm

[Goosedog]

http://www.thumperfaq.com/swingarm.htm

Yup, that's the one. Thanks GR

[Goosedog]

As I repack all the bearings in the swingarm linkage I'm suprized to find this apparent design flaw from the factory.

In the pivot housing (or relay arm) when the needle bearing inner races are pressed back in and touch in the middle, they are still about 2mm from sealing off against the outside housing. This is an invitation for dirt and water no matter how well greased.

Has anyone tried fitting an o-ring or makeshift bearing seal in there to protect the needle bearings?

[tnl]

I posted a question about ths also last month and was interested in finding out if it was normal also? I think I called it "free play" at the connecting rod/relay arm assembly! I have about 3 hours on it after doing a complete swingarm service with that "free play" in it and have no problems...But yea, I would say that it is somewhat of a design flaw even though there is an oil seal at that location! I know GrayRacer513 will probably disagree though:.)

[grayracer513]

The needle bearings need to run far enough down into the part they press into that there is room for a seal over them. The seal seals between the bearing bore and the the inner race/sleeve. I'm not sure exactly what you're describing.

End play at the rely arm or connecting rod is not particularly important.

[Goosedog]

The needle bearings need to run far enough down into the part they press into that there is room for a seal over them. The seal seals between the bearing bore and the the inner race/sleeve. I'm not sure exactly what you're describing.

End play at the rely arm or connecting rod is not particularly important.

Here's the gaps I'm talking about GR. What's left between the steel inner races and the aluminum pivot arm housing. I realize just inside this gap is a seal before the actual bearing but wouldn't a 1mm nylon washer or something like that be helpful in keeping dirt and water from getting a start into this area?

[tnl]

Not sure what year your bike is but that gap in that location didn't exists in my relay arm? That's not right! Make sure those collars are pressed in there good with your fingers. The play that I had was between the outside of your thumb and index finger where it connects to the connecting rod as though the relay arm assembly was too skinny? I would try those new parts that you have in the picture? There isn't really a way to put those parts in backwards so either it's in right or they are the wrong parts/wore out.

[YzGuy79]

My '03 450 is exactly like that and my '01 125 was like that too.

Remember these aren't Hondas. The tolerances aren't going to be that close.

[grayracer513]

Here's the gaps I'm talking about GR. What's left between the steel inner races and the aluminum pivot arm housing. I realize just inside this gap is a seal before the actual bearing but wouldn't a 1mm nylon washer or something like that be helpful in keeping dirt and water from getting a start into this area?

The "gap" you're seeing is end clearance. It's necessary. Without it there would need to be thrust bearings at the ends. That would be an unnecessary complication, since no axial thrust is borne by any of the linkage other than the swing arm.

A boot or a pre-seal of some kind could be used here to keep stuff away from the seals, but you could do that with every seal on the bike, too.

[Yamahafan]

Both my 2002 WR250F and my 2006 YZ450F have a gap/wiggle room where you are indicating. This has been designed in on purpose, but I can't remember why. I like your O-ring idea.

P.S. This is exactly why you shouldn't hit your linkage with a power washer!

[Goosedog]

So, GR and Yamahafan...your both saying that gap (and associated lateral play) is nessesary in this joint, but also that an o-ring or pre-boot would be a good idea. Please elaborate.?

[Yamahafan]

I think a rubber o-ring would keep out dirt, but have enough give to allow the linkage to move laterally if needed. In other words - I don't think you can hurt your linkage by putting a rubber o-ring in there, but you might if you use a nylon washer or other hard piece.