Swing arm bushing failure

Thread starter
max_imp said:
Same here Cormanus, something interesting going on here and thanks Egleaves and Popgun for the input, even when the bolt is over-tightened the threads would just strip and the nut would be hard to remove.

Since the bolt broke close to the nut it was still captive in the frame on both sides and the only thing preventing it from exiting to the left is the plastic cap that clips into the cavity where the head of the bolt resides, good thing that cap is held in tight eh?

Overall a good find from the dealership:worship:
Click to expand...
Exactly what the tech said.
 
Hi All,
I have been experiencing the loud chain for a long time.
I thought so at the time.
Yesterday and today I worked on the replacement of chain and sprockets.
After disassembly of used (32000km) sprockets and chain, I washed them in gasoline.

I noticed that the front sprocket is unnaturally worn on the invisible side (from the inside).
I began to wonder why this happened.
I checked the play on the swing arm.
The test showed about 2mm play at the end of the swing arm.
Now I understand that the noise was caused by the chain rubbing on the front sprocket.
Which was due to a lack of alignment front versus rear sprocket.

BTW, in my opinion adding a shim or turning a bolt will help for short time.
I did the same in my Sachs MadAss last year and after 2000 km of ride the shim rubbed off and the play came back.
In my country it was not possible to buy Sachs parts, therefore i had to do a swing arm bushing to eliminate the problem.
That's my experience.
 
Synchronizator could you post some pictures that show the wear so we can have something tangible?

Not doubting for a second your very in-depth findings and on which side ( left ( needle bearing ) or right ( two ball bearings ) is there movement that causes the 2mm sideways play in the swingarm, assuming the bushings are correctly held in place by the big m18 bolt, see the partsfish link earlier in the thread.
 
When you pull the bolt out put something like a long screwdriver or similar in behind it so it's easier to position the long bushing inside instead of it it falling down in the housing, it helped me.
 
max_imp said:
When you pull the bolt out put something like a long screwdriver or similar in behind it so it's easier to position the long bushing inside instead of it it falling down in the housing, it helped me.
Click to expand...
That's what I exactly did :)
My bolt has very slight usage, the defect is only 0.1 mm.
Turning the bolt does not change anything.
Regardless of whether the bolt is loose or not, my swing arm has a similar 2mm play.
I suspect, however, that the cause is the bearing on the sprocket side.
On the other side everything looks good. No play.
I will disassemble the swing arm on Saturday.





I think the sprocket side will be more likely to fail than the other side , because the working chain puts a heavy load on the bearing.
Other side only just only keeps the swing arm.
 
Thanks that is a great photo and i was hoping you would post it.
What i found in my video is similar to what you show here, the bolt is obviously stationary and so is the bushing ( which is the area the wearmark shows ) the needle bearing provides the pivot for the swingarm.

The bushing is meant to be clamped in place and held inmobile by the force of the bolt compressing the frame and holding all the bushings and bearing inner races together like in a vice.

Mistakenly i am calling this inner assembly "the spacers" but i mean all parts that are directly around the bolt and held captive by it, i don't have a proper name for it.

So if that were the case there would not be any wearmarks on the bolt because nothing directly around it moves, ( this is the smoking gun proof ) the movement is on the outer races of the bearings and the inner races remain inmobile as long as the compressing force of the bolt is enough to hold all these spacers etc. captive together as one lump.

I believe when the bolt is torqued up it exerts over 3 tonnes of compression on the frame and the spacers, if the frame resists too much then not enough force is left to compress the spacers and they roll around creating the wear marks you show.

If you can measure the gap between the frame and the bushings with a feeler gauge, i think in my case it was 0.7 mm.

So to transfer more pressure to the bushings i mostly closed that gap ( with the spacer ) and as a consequence had a lot more pressure left over to clamp the bushings as the design requires rather than pull the frame together, this eliminated any play instantly as shown in the video clip.

In my case the bolt was torqued up fine but all the pressure was used to compress the frame which was quite rigid in that place because of the construction rather than the bushings.

Made a mistake in an earlier post, to clarify; the two roller bearings on the brake side stop the swingarm from moving sideways and provide pivot support, the needle bearing just lands on it's bushing in an arbitrary place and only supports lengthwise , as well as pivot support.

Look forward to your findings and let me know if i missed something, thanks for posting all the details!
 
max_imp said:
Thanks that is a great photo and i was hoping you would post it.
What i found in my video is similar to what you show here, the bolt is obviously stationary and so is the bushing ( which is the area the wearmark shows ) the needle bearing provides the pivot for the swingarm.

The bushing is meant to be clamped in place and held inmobile by the force of the bolt compressing the frame and holding all the bushings and bearing inner races together like in a vice.

Mistakenly i am calling this inner assembly "the spacers" but i mean all parts that are directly around the bolt and held captive by it, i don't have a proper name for it.

So if that were the case there would not be any wearmarks on the bolt because nothing directly around it moves, ( this is the smoking gun proof ) the movement is on the outer races of the bearings and the inner races remain inmobile as long as the compressing force of the bolt is enough to hold all these spacers etc. captive together as one lump.

I believe when the bolt is torqued up it exerts over 3 tonnes of compression on the frame and the spacers, if the frame resists too much then not enough force is left to compress the spacers and they roll around creating the wear marks you show.

If you can measure the gap between the frame and the bushings with a feeler gauge, i think in my case it was 0.7 mm.

So to transfer more pressure to the bushings i mostly closed that gap ( with the spacer ) and as a consequence had a lot more pressure left over to clamp the bushings as the design requires rather than pull the frame together, this eliminated any play instantly as shown in the video clip.

In my case the bolt was torqued up fine but all the pressure was used to compress the frame which was quite rigid in that place because of the construction rather than the bushings.

Made a mistake in an earlier post, to clarify; the two roller bearings on the brake side stop the swingarm from moving sideways and provide pivot support, the needle bearing just lands on it's bushing in an arbitrary place and only supports lengthwise , as well as pivot support.

Look forward to your findings and let me know if i missed something, thanks for posting all the details!
Click to expand...

max_imp said:
Thanks that is a great photo and i was hoping you would post it.
What i found in my video is similar to what you show here, the bolt is obviously stationary and so is the bushing ( which is the area the wearmark shows ) the needle bearing provides the pivot for the swingarm.

The bushing is meant to be clamped in place and held inmobile by the force of the bolt compressing the frame and holding all the bushings and bearing inner races together like in a vice.

Mistakenly i am calling this inner assembly "the spacers" but i mean all parts that are directly around the bolt and held captive by it, i don't have a proper name for it.

So if that were the case there would not be any wearmarks on the bolt because nothing directly around it moves, ( this is the smoking gun proof ) the movement is on the outer races of the bearings and the inner races remain inmobile as long as the compressing force of the bolt is enough to hold all these spacers etc. captive together as one lump.

I believe when the bolt is torqued up it exerts over 3 tonnes of compression on the frame and the spacers, if the frame resists too much then not enough force is left to compress the spacers and they roll around creating the wear marks you show.

If you can measure the gap between the frame and the bushings with a feeler gauge, i think in my case it was 0.7 mm.

So to transfer more pressure to the bushings i mostly closed that gap ( with the spacer ) and as a consequence had a lot more pressure left over to clamp the bushings as the design requires rather than pull the frame together, this eliminated any play instantly as shown in the video clip.

In my case the bolt was torqued up fine but all the pressure was used to compress the frame which was quite rigid in that place because of the construction rather than the bushings.

Made a mistake in an earlier post, to clarify; the two roller bearings on the brake side stop the swingarm from moving sideways and provide pivot support, the needle bearing just lands on it's bushing in an arbitrary place and only supports lengthwise , as well as pivot support.

Look forward to your findings and let me know if i missed something, thanks for posting all the details!
Click to expand...
I need to think about it
Now i undrstand the idea of "the spacer" implementation, but am not sure where the measurement should be taken. Tommorow after work I will buy the tool search and measure.

My todays swing arm play check:

Good Night :)
 
Good morning, thanks for the video, i assume the bolt was torqued up when the video was taken, it appears that the "collars"are still not compressed,feel free to click on Popgun's link and partsfish will open in a new window, have a look at parts; 6, 8 and 9, they all "thread" onto no 7 ( the bolt ) and need to be clamped tight in order to function as designed, i agree, it needs a bit of thought to figure out how it is supposed to function, i hope my video helps to understand how that happens despite the brief text.
http://cb1100forum.com/forum/showthread.php?tid=14993&pid=255014#pid255014

Even if there is a slight gap of less than 0.1 mm the collars are then free to move on the bolt and produce the play you demonstrate.

The shim ( it's actually a washer ) can be placed either between no6 and the frame ( brake side ) or between no9 ( on the sprocket side ) and the frame.
Mine is made from brass sheet because of the low oxidation properties and the hole was drilled first and has a close fit around the shaft, it was then cut out
to conform to the swingarm shaft but such that it could be manipulated in place without too much difficulty.

Normally there is no need to remove the swingarm but it may be interesting to do so, at the same time maybe check for sufficient grease in the bearings and
where the shock absorbers mount to the frame, they were dry on my bike and a little brown dust had formed, up to you.

The other issue is that water could have entered inside the swingarm through the gap, ignoring the dust ( water ) seals on either side of the bearing area,
i'm thinking the bearings themselves may have been affected depending how much grease has been used in assembly.

You are well on the way to solve this thing, good stuff:thumbsup:
 
syncronizator_imp said:
max_imp said:
Thanks that is a great photo and i was hoping you would post it.
What i found in my video is similar to what you show here, the bolt is obviously stationary and so is the bushing ( which is the area the wearmark shows ) the needle bearing provides the pivot for the swingarm.

The bushing is meant to be clamped in place and held inmobile by the force of the bolt compressing the frame and holding all the bushings and bearing inner races together like in a vice.

Mistakenly i am calling this inner assembly "the spacers" but i mean all parts that are directly around the bolt and held captive by it, i don't have a proper name for it.

So if that were the case there would not be any wearmarks on the bolt because nothing directly around it moves, ( this is the smoking gun proof ) the movement is on the outer races of the bearings and the inner races remain inmobile as long as the compressing force of the bolt is enough to hold all these spacers etc. captive together as one lump.

I believe when the bolt is torqued up it exerts over 3 tonnes of compression on the frame and the spacers, if the frame resists too much then not enough force is left to compress the spacers and they roll around creating the wear marks you show.

If you can measure the gap between the frame and the bushings with a feeler gauge, i think in my case it was 0.7 mm.

So to transfer more pressure to the bushings i mostly closed that gap ( with the spacer ) and as a consequence had a lot more pressure left over to clamp the bushings as the design requires rather than pull the frame together, this eliminated any play instantly as shown in the video clip.

In my case the bolt was torqued up fine but all the pressure was used to compress the frame which was quite rigid in that place because of the construction rather than the bushings.

Made a mistake in an earlier post, to clarify; the two roller bearings on the brake side stop the swingarm from moving sideways and provide pivot support, the needle bearing just lands on it's bushing in an arbitrary place and only supports lengthwise , as well as pivot support.

Look forward to your findings and let me know if i missed something, thanks for posting all the details!
Click to expand...

max_imp said:
Thanks that is a great photo and i was hoping you would post it.
What i found in my video is similar to what you show here, the bolt is obviously stationary and so is the bushing ( which is the area the wearmark shows ) the needle bearing provides the pivot for the swingarm.

The bushing is meant to be clamped in place and held inmobile by the force of the bolt compressing the frame and holding all the bushings and bearing inner races together like in a vice.

Mistakenly i am calling this inner assembly "the spacers" but i mean all parts that are directly around the bolt and held captive by it, i don't have a proper name for it.

So if that were the case there would not be any wearmarks on the bolt because nothing directly around it moves, ( this is the smoking gun proof ) the movement is on the outer races of the bearings and the inner races remain inmobile as long as the compressing force of the bolt is enough to hold all these spacers etc. captive together as one lump.

I believe when the bolt is torqued up it exerts over 3 tonnes of compression on the frame and the spacers, if the frame resists too much then not enough force is left to compress the spacers and they roll around creating the wear marks you show.

If you can measure the gap between the frame and the bushings with a feeler gauge, i think in my case it was 0.7 mm.

So to transfer more pressure to the bushings i mostly closed that gap ( with the spacer ) and as a consequence had a lot more pressure left over to clamp the bushings as the design requires rather than pull the frame together, this eliminated any play instantly as shown in the video clip.

In my case the bolt was torqued up fine but all the pressure was used to compress the frame which was quite rigid in that place because of the construction rather than the bushings.

Made a mistake in an earlier post, to clarify; the two roller bearings on the brake side stop the swingarm from moving sideways and provide pivot support, the needle bearing just lands on it's bushing in an arbitrary place and only supports lengthwise , as well as pivot support.

Look forward to your findings and let me know if i missed something, thanks for posting all the details!
Click to expand...
I need to think about it
Now i undrstand the idea of "the spacer" implementation, but am not sure where the measurement should be taken. Tommorow after work I will buy the tool search and measure.

My todays swing arm play check:

Good Night :)
Click to expand...

max_imp said:
Thanks that is a great photo and i was hoping you would post it.
What i found in my video is similar to what you show here, the bolt is obviously stationary and so is the bushing ( which is the area the wearmark shows ) the needle bearing provides the pivot for the swingarm.

The bushing is meant to be clamped in place and held inmobile by the force of the bolt compressing the frame and holding all the bushings and bearing inner races together like in a vice.

Mistakenly i am calling this inner assembly "the spacers" but i mean all parts that are directly around the bolt and held captive by it, i don't have a proper name for it.

So if that were the case there would not be any wearmarks on the bolt because nothing directly around it moves, ( this is the smoking gun proof ) the movement is on the outer races of the bearings and the inner races remain inmobile as long as the compressing force of the bolt is enough to hold all these spacers etc. captive together as one lump.

I believe when the bolt is torqued up it exerts over 3 tonnes of compression on the frame and the spacers, if the frame resists too much then not enough force is left to compress the spacers and they roll around creating the wear marks you show.

If you can measure the gap between the frame and the bushings with a feeler gauge, i think in my case it was 0.7 mm.

So to transfer more pressure to the bushings i mostly closed that gap ( with the spacer ) and as a consequence had a lot more pressure left over to clamp the bushings as the design requires rather than pull the frame together, this eliminated any play instantly as shown in the video clip.

In my case the bolt was torqued up fine but all the pressure was used to compress the frame which was quite rigid in that place because of the construction rather than the bushings.

Made a mistake in an earlier post, to clarify; the two roller bearings on the brake side stop the swingarm from moving sideways and provide pivot support, the needle bearing just lands on it's bushing in an arbitrary place and only supports lengthwise , as well as pivot support.

Look forward to your findings and let me know if i missed something, thanks for posting all the details!
Click to expand...
I need to think about it
Now i undrstand the idea of "the spacer" implementation, but am not sure where the measurement should be taken. Tommorow after work I will buy the tool search and measure.

My todays swing arm play check:

Good Night :)
 
Yes, the bolt was torqued up when the video was taken.
I haven't bought the feeler gauge yet, after that also need to buy propper spacers.
I will probably do it on Saturday and let you know after completing the work.
 
Thread starter
After 19 days in the shop I finally get to pick up my bike this afternoon! They wound up replacing the entire assembly that holds the swing arm to the frame....nut, bolt, bearings and all. Best news is that Honda Care is picking up the $450 bill! I'm supposed to be getting the old parts back too, so I should be able to share pics of the failure.
 
egleaves_imp said:
After 19 days in the shop I finally get to pick up my bike this afternoon! They wound up replacing the entire assembly that holds the swing arm to the frame....nut, bolt, bearings and all. Best news is that Honda Care is picking up the $450 bill! I'm supposed to be getting the old parts back too, so I should be able to share pics of the failure.
Click to expand...
Would like to see them
 
Thread starter
Picked up the bike and was finally able to see the broken bolt. The bolt broke off inside the nut! This is clearly beyond normal wear and tear.

The service manager has a background in....structural inspection...something like that....we didn’t get into it. Anyway, he told Honda that it appeared to be a manufacturing defect and they took him at his word and made good on the warranty. Now they want to see the bolt. Hopefully they’ll be able to do some forensic analysis to deduce whether this was an isolated case, or there’s a broader risk.

Early on I was told I could keep the old parts, but now Honda wants them as evidence. I totally get that. I was “allowed” to take pictures of it so I staged a small photo shoot at the service desk. Sorry for the teaser, but the only way I can manage to post pics is from my work computer. Have to do it tomorrow.
 
So far that's a very good outcome, good communication all round and some solid work from your dealer, congrats:biker:

On that happy note i had a look at my own rear wheel alignment and took some pictures of how i did that, i was off by 2mm. to the right and adjusted that to 0mm.
There was nothing i noticed whilst riding but have felt some unease with 5mm. misalignment, the lengthwise seams in the road start to have a small effect on the steering;

This only worked well on the sidestand, the centerstand was in the way of the string and was not reliable, as a shortcut you could look past the rear wheel's sides and check if they are in-line with the outside of the disk ( on the left side ).
 
egleaves_imp said:
Picked up the bike and was finally able to see the broken bolt. The bolt broke off inside the nut! This is clearly beyond normal wear and tear.

The service manager has a background in....structural inspection...something like that....we didn’t get into it. Anyway, he told Honda that it appeared to be a manufacturing defect and they took him at his word and made good on the warranty. Now they want to see the bolt. Hopefully they’ll be able to do some forensic analysis to deduce whether this was an isolated case, or there’s a broader risk.

Early on I was told I could keep the old parts, but now Honda wants them as evidence. I totally get that. I was “allowed” to take pictures of it so I staged a small photo shoot at the service desk. Sorry for the teaser, but the only way I can manage to post pics is from my work computer. Have to do it tomorrow.
Click to expand...
Egleaves
Did you check after Honda replaced the bearings and other elements of the swing arm, is there no play?
Perhaps the new parts were produced badly and the swing arm still has a little play. You have everything new. There is an opportunity to verify it.
Normally no one checks it when buying a new motorcycle.
 
Yesterday evening I checked with a feeler gauge if there is a room for the shim we were talking about.
In my situation, torsion of the bolt definitely squeezes the frame, all "collars" and bearings.
Maybe I was looking wrong. However, I think that if there is slack there, the swing arm could slide on the bolt by e.g. 0.7 mm across the motorcycle (left <=> right).
This only happens when the bolt is unscrewed because the frame flexes and slack occurs.
I will try to dismantle the swing arm tomorrow.
I hope I can find the reason. Maybe I'll make a movie.
 
Here's the confusing part Synchronizator; my swingarm still moves sideways by a mm or so, it slides quite freely when i push and pull on the swingarm close to the hingepoint but the movement is sideways only and does not sway the swingarm out of alignment.

What ? this is the sideways play that is limited by the two roller bearings movement in their housing limited by the circlip ( no20 ) , the needle bearing is able to move sideways on it's flanged collar and that's fine.

the sideways play you want to correct has to be measured with the bolt loose to check for free play of the collars, there should be next to nothing, 0,1mm free play before the bolt is torqued up to spec. and you may have to put a screwdriver in the gap to keep the collars toghether whilst the measurement takes place.

So be sure to measure the correct ( fore and aft movement ) that is happening when you move the wheel sideways as you demonstrated in your video.

And yes, valid question for egleaves, i agree and hopefully he has some pictures of all the replaced parts for us, that would be a first and very welcome.
 
You must log in or register to reply here.
Back
Top