Swing arm Bronze bushing /thrust cover

hard_y_rd

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I'm about to do my first bronze bushing install and was wondering if the thrust covers (grease seals) need to be installed? I would imagine yes but i could be wrong. I did some searching and didn't get confirmation if they are reused.
 
The grease still needs to be held in there by something! So yes. ;)
xs650c_build_11.png
 
Oh yes, they have to be there because besides keeping the grease in they keep the bearing sleeve clamped solid in the frame.
Note that if the bearing sleeve is allowed to rotate the swingarm will pivot on the sloppy steel on steel fit between the inside of the sleeve and the swingarm throughbolt.
 
Sideplay needs to be checked, adjust by adding or subtracting shims.

Hi Gary,
you are correct and because some folks don't get it right and then claim their bikes don't steer too good I'm gonna spell it out in full.
The bearing sleeve and the seal washers must be bolted solidly in the frame so that the swingarm bushings move against the bearing sleeve.
There should be enough clearance to allow the swingarm to drop under it's own weight when the bearing sleeve is locked in place.
If the swingarm cannot move freely DO NOT slacken off the throughbolt to let it move. If you do that the bearing sleeve will turn with
the swingarm and the bearing movement will no longer be between the sleeve and the bushings, it will be a bad sloppy fit between
the inside of the sleeve and the outside of the throughbolt.
You must put Yamaha's stock shims at the end of the bearing sleeve to get enough clearance to let the swingarm move freely when the throughbolt
nut is fully tightened. 0.002" to 0.012" is the recommended clearance.
&BTW, it's best you replace the stock M14-ended throughbolt with the M16-ended one.
The M14 ends tend to snap off which lets the throubolt fall out onto the street which in turn locks the rear tire against the fender.
My bike left a 100-foot skidmark to prove it.
 
Thanks for the replies. What do the stock yamaha shims look like? I don't think they were there when I took the Swing arm out.
 
Factory shims are inside the grease cups, easily missed and only on some bikes as needed. Also check arm assembled with grease caps to frame clearance before tightening the end nut, if there is room for a 3/4"ID shim put one in. Don't wrack the frame to take up excessive clearance. IMHO that is one reason for thread failure. I might be an oddity but after well over 30 XS650's prolly 8 or 10 bushing / bearing installs I have yet to see a snapped thread.
 
Side play can and should be calculated before installing the bushings. With a 12" caliper, measure the width of the swingarm, and add the thickness of both outer bushing flanges. Subtract that total from the length of the inner bushing (tube); that's the side play. If more side play is needed, use a flat file to remove material from the edges of the swingarm; those are beveled surfaces in mild steel and very easy to work.

Right, Gary, I've never snapped the threads off a swingarm axle either. That thing is actually a pinch bolt that clamps the frame. Applying less than spec torque to let the swingarm move in an incorrect assembly is going to allow a lot of flex, and flex is what does the damage.
 
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If you have to add shims wouldn't that defeat the purpose of the inner tube/ spacer/flange whatever you call it being just proud of the bushing surface?
 
That's right; that's why you should install additional shims to reduce side play if and only if there's too much side play. I know you destroyed your suspension with a hard tail, but you can think this through if you try real hard!
 
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Loose the hardtail because it should be stirred not shaken........LOL
Some brass bushing flanges are thicker than the oem bushing flange. No reason you cant work the flanges down with a file if you are confident you can keep it REALLY flat and square. Once the bushings are in it's kind of hard to file the swing arm ends...... Excessive frame to SA assembly clearance is a different issue than setting the side play with shims. It's not always an issue or even a common problem but it happens. It's one of my soapbox things that bending the frame in to take up too much slop is plain wrong for several reasons.
 
Loose the hardtail because it should be stirred not shaken........LOL
Some brass bushing flanges are thicker than the oem bushing flange. No reason you cant work the flanges down with a file if you are confident you can keep it REALLY flat and square. Once the bushings are in it's kind of hard to file the swing arm ends...... Excessive frame to SA assembly clearance is a different issue than setting the side play with shims. It's not always an issue or even a common problem but it happens. It's one of my soapbox things that bending the frame in to take up too much slop is plain wrong for several reasons.

Hi Gary,
you've not ever had an M14 throughbolt end fall off, eh?
You've lucked out because TWO of mine fell off before I gave up on buying stock replacements and kludged in an M16 ended bolt from a Suzuki.
That was way before you could buy (or perhaps before I found out about) the M16 ended aftermarket replacements.
And I don't see how you can "bend the frame in too much" on an XS650.
The XS650's frame/bearing sleeve/throughbolt triad bolts up solid to lock everything into place to make that area more rigid
so the frame will only bend in "just enough" before it can't bend any more because it'll be bolted solid onto the bearing sleeve.
Should there be excessive swingarm sideplay after the throughbolt is tightened the only fix I can see is grinding the throughbolt shorter or putting a shim between the swingarm bushing's flange and the sealing washer.
The factory only adds shims between the bearing sleeve and the sealing washers when it's necessary to make the bearing sleeve effectively longer should the
swingarm not have enough side-play to move freely after the throughbolt is tightened.
I'd suppose that the factory used shims because adding shims to increase the bearing sleeve's effective length is WAY cheaper than doing a mix'n'match assembly with stock plastic swingarm bushings of different flange thicknesses and/or bearing sleeves of different lengths.
 
That's incorrect Fred, you have it backwards. The factory added shims make the swingarm/bushing assembly longer if the pivot sleeve turns out to be too long. The shims fit over the ends of the pivot sleeve, not against it, and rest against the swingarm bushings.

In fact, Yamaha still sells the shims. They were used (if needed) on a ton of different models. You can see by the picture that the shim's I.D. is quite large and the shim won't hit on the pivot sleeve but rather fit around it .....

http://www.boats.net/parts/detail/yamaha/Y-240-22127-00-00.html
 
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I haven't got all the parts in hand yet so I was just planning ahead in my head. I'll have to see if the bushings meet all tolerances before install.Thanks for all the replies
 
As mentioned, the shims aren't needed very often. I only found them once in probably a good half dozen I've pulled apart. A more common issue is that sometimes the flanges on the aftermarket bronze bushings are a little too thick. You end up with a swingarm/bushing assembly that's too long in relation to the pivot tube. Also, this can happen if you powder coat the swingarm and don't clean it off the ends of the bushing bores before installing them. Powder is thicker than paint, sometimes it's too thick.
 
That's incorrect Fred, you have it backwards. The factory added shims make the swingarm/bushing assembly longer if the pivot sleeve turns out to be too long. The shims fit over the ends of the pivot sleeve, not against it, and rest against the swingarm bushings.

In fact, Yamaha still sells the shims. They were used (if needed) on a ton of different models. You can see by the picture that the shim's I.D. is quite large and the shim won't hit on the pivot sleeve but rather fit around it .....

http://www.boats.net/parts/detail/yamaha/Y-240-22127-00-00.html

Hi 5twins,
well, there I go, wrong again, eh?
Let me snivel in my own defence:-
My bike never had no steenkin' shims and the crummy little drawing in my Clymers is nowhere near as clear as that linked photo as to the shim's size and hence it's location.
& BTW, when I installed my bronze swingarm bushings the swingarm ended up too wide to move freely after the throughbolt was tightened. Fixed that with careful use of a 14" mill/bastard file.
But you gotta admit, if they HAD made a shim to extend the bearing sleeve it WOULD have worked like I said.
(going down with the ship, waving the flag, defiant to the end.)
 
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