I thought I'd compile the essential elements of the swingarm procedures from my other recent thread
http://www.xs650.com/threads/yet-another-swingarm-bushing-thread.51061/
....into a more coherent, single post for those who might want to read the info more easily for their own installation.
This applies to all XS650 years, and I used Mikes' Bronze bushings, purchased recently.
I did some measuring of dimensions to see exactly what I had:
The proper, expected dimensions of this bushing are:
Length 40mm
ID 22mm
OD 28mm
Collar thickness 2.6mm
Collar OD 34mm
Using a new, calibrated Fowler, I got these measures at 65 degrees F:
Bushing One:
Length 40.06 mm
ID 22.03 mm
OD 28.04 mm
Collar thickness 2.50 mm
Collar OD 34.07 mm
Bushing Two:
Length 40.03 mm
ID 22.05 mm
OD 28.05 mm
Collar thickness 2.60 mm
Collar OD 34.10 mm
I noted the largest variation in bold.
The OD increased on both bushes by .02 just in front of the collar.
The old nylon bushes tend to be really stuck in there. Make cuts like in the photo below to relieve the tension of the material. Cut almost down to the metal. Then heat with a propane torch until the grease boils, but before the paint gets singed. Knock it out with a long drift. I used a section of copper water pipe.
After 24 hours in the freezer, the OD of the new bronze bush was reduced by .04 mm.
Reheat the arm with a torch and assemble an installation tool made of all-thread, fender washers, and two nuts.
Quickly assemble the tool and your cold bushings. I pressed both at once, which worked, but the torque required in the last 1/2 inch became very strenuous due to the cooling of the arm and warming of the bush.
I suggest pressing one at a time.
The pivot tube should fit nicely, smoothly. Some have reported having to do a bit of machining/reaming of the bushes to get a good fit. Sometimes the pivot tube is badly rusted; in that case, replace it.
Aligning the tube and the bushing at one end ("flatting them"),
....a measurement can be easily made at the other end with a feeler gauge.
I am inclined to suggest a target figure of .008 and a range of .006" to .010" for this pre-assembly sideplay or freeplay, based upon my experiences and measures taken during two installations, and the technical information available to us.
The .040" figure found in your Yamaha Service Manual is a wear limit for inspection purposes to be applied later, after many miles of use, and therefore not a figure which we would want to be using when doing our pre-assembly bench set-up.
The sideplay or freeplay is the distance the pivot tube emerges past the collar of the bushing when you set it up on the bench as I did in the photos. This distance becomes your sideplay. You might have to add a shim if your sideplay comes out to be larger than .010.
To quote 5T,:
"The shims are actually used if the pivot tube is too long compared to the swingarm/bushing assembly. They are installed inside the grease seals. They have an I.D. big enough to go over the pivot tube - they don't shim against it. This doesn't happen on most swingams so you don't find the shims very often. You need to thoroughly clean the old grease seals and look inside them to see if shims are present. Most probably get tossed out with the old grease seal because folks aren't even aware they might be in there. Out of the half dozen of so swingarms I've taken apart, I only found shims in one."
On one of my installations, the sideplay was too small, so I carefully filed down the collar until I achieved the correct play. You can see this in the last photo, above.
Next, install the swingarm, using the new end seals if yours were at all bunged-up.
5Twins offers the following torquing procedure to assist in fine-tuning your sideplay:
" When installing the swingarm, I would use the pivot bolt torque range given in the '77 torque spec chart (36-58 ft/lbs), not the single value given in some of the other years manuals (something like 47 ft/lbs). When you install one of these, the usual procedure is to torque the pivot bolt until it is in the specified range and so that the arm very slowly falls under it's own weight. That may not happen exactly at 47 ft/lbs (probably won't). It will probably require a bit more or less than that. If it stays loose above the max torque spec, you've got too much play. If it binds up completely before you even reach the minimum spec, you don't have enough play."
The results of my recent torquing procedures, per the recommendation of 5T:
> The 1980 was set at .008, and the arm fell slowly at about 38 ft. lbs.
> The 1976 was set at .010, and the arm fell slowly at about 42 ft. lbs,
the results of which seem to validate that the .006 to .010 range of pre-assembly sideplay is a good starting point.
fini
.
.
http://www.xs650.com/threads/yet-another-swingarm-bushing-thread.51061/
....into a more coherent, single post for those who might want to read the info more easily for their own installation.
This applies to all XS650 years, and I used Mikes' Bronze bushings, purchased recently.
I did some measuring of dimensions to see exactly what I had:
The proper, expected dimensions of this bushing are:
Length 40mm
ID 22mm
OD 28mm
Collar thickness 2.6mm
Collar OD 34mm
Using a new, calibrated Fowler, I got these measures at 65 degrees F:
Bushing One:
Length 40.06 mm
ID 22.03 mm
OD 28.04 mm
Collar thickness 2.50 mm
Collar OD 34.07 mm
Bushing Two:
Length 40.03 mm
ID 22.05 mm
OD 28.05 mm
Collar thickness 2.60 mm
Collar OD 34.10 mm
I noted the largest variation in bold.
The OD increased on both bushes by .02 just in front of the collar.
The old nylon bushes tend to be really stuck in there. Make cuts like in the photo below to relieve the tension of the material. Cut almost down to the metal. Then heat with a propane torch until the grease boils, but before the paint gets singed. Knock it out with a long drift. I used a section of copper water pipe.
After 24 hours in the freezer, the OD of the new bronze bush was reduced by .04 mm.
Reheat the arm with a torch and assemble an installation tool made of all-thread, fender washers, and two nuts.
Quickly assemble the tool and your cold bushings. I pressed both at once, which worked, but the torque required in the last 1/2 inch became very strenuous due to the cooling of the arm and warming of the bush.
I suggest pressing one at a time.
The pivot tube should fit nicely, smoothly. Some have reported having to do a bit of machining/reaming of the bushes to get a good fit. Sometimes the pivot tube is badly rusted; in that case, replace it.
Aligning the tube and the bushing at one end ("flatting them"),
....a measurement can be easily made at the other end with a feeler gauge.
I am inclined to suggest a target figure of .008 and a range of .006" to .010" for this pre-assembly sideplay or freeplay, based upon my experiences and measures taken during two installations, and the technical information available to us.
The .040" figure found in your Yamaha Service Manual is a wear limit for inspection purposes to be applied later, after many miles of use, and therefore not a figure which we would want to be using when doing our pre-assembly bench set-up.
The sideplay or freeplay is the distance the pivot tube emerges past the collar of the bushing when you set it up on the bench as I did in the photos. This distance becomes your sideplay. You might have to add a shim if your sideplay comes out to be larger than .010.
To quote 5T,:
"The shims are actually used if the pivot tube is too long compared to the swingarm/bushing assembly. They are installed inside the grease seals. They have an I.D. big enough to go over the pivot tube - they don't shim against it. This doesn't happen on most swingams so you don't find the shims very often. You need to thoroughly clean the old grease seals and look inside them to see if shims are present. Most probably get tossed out with the old grease seal because folks aren't even aware they might be in there. Out of the half dozen of so swingarms I've taken apart, I only found shims in one."
On one of my installations, the sideplay was too small, so I carefully filed down the collar until I achieved the correct play. You can see this in the last photo, above.
Next, install the swingarm, using the new end seals if yours were at all bunged-up.
5Twins offers the following torquing procedure to assist in fine-tuning your sideplay:
" When installing the swingarm, I would use the pivot bolt torque range given in the '77 torque spec chart (36-58 ft/lbs), not the single value given in some of the other years manuals (something like 47 ft/lbs). When you install one of these, the usual procedure is to torque the pivot bolt until it is in the specified range and so that the arm very slowly falls under it's own weight. That may not happen exactly at 47 ft/lbs (probably won't). It will probably require a bit more or less than that. If it stays loose above the max torque spec, you've got too much play. If it binds up completely before you even reach the minimum spec, you don't have enough play."
The results of my recent torquing procedures, per the recommendation of 5T:
> The 1980 was set at .008, and the arm fell slowly at about 38 ft. lbs.
> The 1976 was set at .010, and the arm fell slowly at about 42 ft. lbs,
the results of which seem to validate that the .006 to .010 range of pre-assembly sideplay is a good starting point.
fini
.
.
Last edited:
