Swing arm Pivot tube

The shims are not between the pivot tube and seal. They are between the swing arm and seal. If the pivot tube extends too far out of the swing arm yiou will have to much side to side play. The shims fill in this excess.
The pivot tube only sticks out a few thousands to let the swing arm pivot around the pivot tube,
Leo
 
That's exactly what we've been trying to explain. The design of the swing arm is crude, and a small amount of side play has to be present if you don't want to lock up the swing arm when spec torque is applied.
 
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Ok, I have filed the bushes down to a point where I have about .75mm extended beyond both bushes, (as per attached photos). Will I now buy shims to take up any clearance between the grease seals and the bushing surface? In your opinions, do the bushing flanges appear too thin now - they are about 2mm thick? Should I put it back together and see if it wiggles? Where can I buy Yamaha shims either in Oz or the states?
 
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The bushings look fine. They don't make a lot of contact, if any, so they won't wear down. The originals were plastic anyway, so the brass ones are a whole lot stronger.
You need to install the swingarm and check for side-side play to figure out if you need shims. Make sure you torque it to the correct spec.
 
littlebill31 said:
The bushings look fine. They don't make a lot of contact, if any, so they won't wear down. The originals were plastic anyway, so the brass ones are a whole lot stronger.
You need to install the swingarm and check for side-side play to figure out if you need shims. Make sure you torque it to the correct spec.
Click to expand...
That's a relief Bill. Take your point about the plastic originals. Will put it back together and give it a shake. 47ft/lb+ according to others in the forum. If it wobbles I'm still in the market for shims. Possible suppliers anyone?
Cheers
 
No, you do not need to install the swing arm and then check for side play. What you need to do is to accurately measure the length of the tube, accurately measure the width of the swing arm, and subtract swing arm width from tube length--that's your side play. .030" (.75 mm.) is too much, Yamaha's late literature specifies a maximum of .020", and less is better, as little as .004" (.01 mm.) will do it. Ever hear the line that goes "Measure twice, cut once?" At this point you probably do need shims. This should not be turned into a cut-and-try job. Measure and be done!
 
David, as I will soon enough be tackling this job myself I am following this with interest. On the face of it , it seems like such a simple job, that gets pretty technical in the end. One hates to have to buy precision measuring tools that after one job , will probably hang on the wall forever gathering dust. Maybe I'm just too frugal haha! Good luck to you.
Bob
 
This is what I purchased from Heiden Tuning, you might be able to buy shims from an engineering suppliers here in AU though.....

Description Number Price Total
#28-1024 - Bronze Swingarm Bushings 1 35.00 EUR 35.00 EUR
#28-1025 - Swingarm Grease Seal price [ set 2 pc] 1 16.00 EUR 16.00 EUR
#27-1068 - Bushing Swing Arm Bolt Tube 1 32.00 EUR 32.00 EUR
#27-1067 - Swingarm Pivot Bolt (Shaft) '74-'84 models 1 34.00 EUR 34.00 EUR
#27-0297 - Swingarm Pivot Nut Locktab 1 3.50 EUR 3.50 EUR
#HT-2127 - shim , swingarm 0,3mm 2 1.00 EUR 2.00 EUR

Cheers Mick
 
It would have to be a cold day in Hell before I'd pay over $7 for one of those things, lol. Look them up under the "156" part number, they're less than a buck that way.
 
Wow grizld1, haven't been spoken to that way since my old man died! Kinda missed it. I do take your point about being a file samurai, enthusiasm shouldn't replace precision but as Mailman says, I don't have the sort of equipment that could accurately measure the dimensions involved and the eyesight isn't what it used to be when it comes to a steel rule.
I'm glad you're on board Mailman but I must admit that I would prefer to be observing your efforts, which I'm sure, would have been completed with precision and foresight.
My thanks Michaelo, Johnny c14 and Bill for your interest and info. I will look at those suppliers although I'll ring my local Yammie dealer with the 156 part number first as 5twins suggests just in case they have a set lying in a drawer... or maybe Mikes.... or maybe a new set of bushes and start again..... or my local motorcycle wrecker.... or maybe just throw myself on my file. Life is difficult for the quasi-mechanic.
Cheers
 
Geoff's XS doesn't have them, Mikes XS might, try Heiden or a local engineering shop, failing that lot, I'd make two out of brass shimming material David
 
If .75mm is the total it sticks out (both sides added together) then one .3mm thick shim per side will do. If it's sticking out .75mm on each side (1.5mm total), you'll need 2 shims per side.
 
This is how I dealt with the swing arm side clearance issue. I used a 12" vernier caliper to measure the length of the pivot tube and then the overall width of the swing arm, bushing face to bushing face. The swing arm measures 7.745" and the tube measured 7.764".

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The tube is .019" longer than the swing arm and goal is to reduce that difference to about .004' but using a shim that the tube can pass through and that butts against the side surface of a swing arm bushing and in my case a .015" shim would be perfect. The Yamaha part 156-22127-00 is .3 mm or .012" which would have been OK but of course I don't have one and don't want to wait to order one. I used a .015" hardened steel shim that was meant to use under the valve spring on a small block Chevrolet V8. It started out with an ID of .700 and an OD of 1.5" and I have a few of them in my spares box. I stacked 4 together (to give them enough strength not be crushed by the lathe chuck) and chucked them in the lathe and used a boring bar to open the ID to 22 mm or .860" so they will slide over the OD of the tube. This is the shims after the ID was machined. The OD is too large to fit inside the swing arm seal.

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Then I made up an arbor to center the shim being held by the ID so I could turn the OD to 34 mm or 1.325 to fit against the end of the bushing inside the seal. The ID of the shim fits over the smallest hub of the arbor and is held there by the recessed washer. Then the OD is machined to the same size as the OD of the arbor hub.

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This is the finished shim and it fits inside the seal. After the swing arm was mounted and the nut torqued to 45 Lb Ft The swing arm pivots nicely with just the slightest amount of drag and no perceptible side play.

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I have 3 extra shims now so if you need one I will send one to you for the cost of postage. I have 2 more .015" shims and one .030" shim.

John
 
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John, that level of prefabrication is truly impressive and, of course, totally beyond my capabilities and equipment. I will purchase the Vernier caliper and measure it up. At the moment I have a local motorcycle wrecker dismantling the swing arm on a GS 750. The arm is damaged but he seems to recall it having shims that may fit.
If not, I'll certainly be in touch after I measure the thing.
Tell me, do I have to balance the number of shims on each side or can I have 2 on one side and one on the other?
The detail of your response and the time taken to prepare it, is an indication of the generosity of many in this forum.
Cheers
 

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