I have a 2010 ST 1300 with 27k miles on the clock.
Last fall I posted a thread about a 'clunk' that I heard when upshifting, especially under load (it started going from 4th to 5th, and progressed to all gears). This noise sounded to me like the center stand had been released and it slapped up under the engine. Suggestions were the rear drive and U-joint. Subsequent investigations revealed no rear end play or noise - in fact, this clank seemed to be coming from the front of the engine. A mechanic thought it was the Primary Damper Shaft (pg 9-27 in The Book) - he concluded that the spring was weak and the damper cam was worn. So, the front of the bike was pulled apart, and this was replaced. Along the way, he dropped the oil pan and looked at the transmission and whatever else he could see from below - everything is good, he said. All the clutch plates are in good condition w/ little or no wear. Clutch basket is likewise in good condition. Nothing visible is obviously damaged or making noise.
After replacing this shaft/cam, the noise was still present. Advice was to ride the bike until something broke - or tear the beast apart and look at every little part. After Uncle Phil's RTE, a new noise was evident. Upon starting the cold bike, there is no noise, but as it warms up a rattling (gravel in the clutch housing) sound becomes evident. I took this to a highly recommended independent mechanic (see below) who works primarily on Gold Wings. He poked and prodded, used a stethoscope w/ a steel rod on whatever parts of the running engine he could reach and came up with a different diagnosis. The noise is loudest on the right side of the bike behind the clutch cover (near the water pump). This noise is not present when you start a cold bike, but as it warms up, it goes away. The clunk I described above and in my original post is still there when I upshift. Said noise goes away when you rev the bike, and at idle, when it is very obvious, it changes if the clutch is pulled in.
His explanation is the spring(s) in the two piece primary drive gear are broken (page 9-25,26 in the Service Manual). The noise is not heard when you start a cold bike because the rpms are up, and with no load but the drag of the clutch there is no tendency to rattle. Let the rpms drop (as the bike comes off fast idle) and the drag decreases and the pulses from the engine cause the two pieces of the gear to make noise. This noise is loudest through the stethoscope on the part of the engine where this gear is housed (he could reach near the water pump), and lowest at the rear of the engine.
My questions: 1. Has anyone experienced anything like this? i.e. problems with the primary drive gear/springs.
2. Any other ideas? I questioned the drive chain for the water pump but he said once the bike is opened up this would be available for inspection as well. The bike shows no cooling problems.
3. Any comments suggestions would be welcome.
4. Does anyone have available for loan the clutch center holder, and gear holder 2.5? I would, of course, pay postage r/t.
P.S.'s My original post LINKY.
This independent mechanic has his own shop next to his house in Northeast rural Ohio. He works primarily on Goldwings, is AMI certified, and came highly recommended from a friend. I have not used him yet, but I'm impressed with his shop (clean, orderly, organized, crammed full of tools), his demeanor, his methodology, and willingness to take time to look at a stranger's bike. If you have a Goldwing or Valk, and don't want to work on it yourself, you might want to give him a try. I hesitate to recommend him here because I want him to be available to me when I need him - grin - not working on your bike. Oh yes, he works alone - no helpers. What you see is what you get. So, if you need a good mechanic, PM me.
Last fall I posted a thread about a 'clunk' that I heard when upshifting, especially under load (it started going from 4th to 5th, and progressed to all gears). This noise sounded to me like the center stand had been released and it slapped up under the engine. Suggestions were the rear drive and U-joint. Subsequent investigations revealed no rear end play or noise - in fact, this clank seemed to be coming from the front of the engine. A mechanic thought it was the Primary Damper Shaft (pg 9-27 in The Book) - he concluded that the spring was weak and the damper cam was worn. So, the front of the bike was pulled apart, and this was replaced. Along the way, he dropped the oil pan and looked at the transmission and whatever else he could see from below - everything is good, he said. All the clutch plates are in good condition w/ little or no wear. Clutch basket is likewise in good condition. Nothing visible is obviously damaged or making noise.
After replacing this shaft/cam, the noise was still present. Advice was to ride the bike until something broke - or tear the beast apart and look at every little part. After Uncle Phil's RTE, a new noise was evident. Upon starting the cold bike, there is no noise, but as it warms up a rattling (gravel in the clutch housing) sound becomes evident. I took this to a highly recommended independent mechanic (see below) who works primarily on Gold Wings. He poked and prodded, used a stethoscope w/ a steel rod on whatever parts of the running engine he could reach and came up with a different diagnosis. The noise is loudest on the right side of the bike behind the clutch cover (near the water pump). This noise is not present when you start a cold bike, but as it warms up, it goes away. The clunk I described above and in my original post is still there when I upshift. Said noise goes away when you rev the bike, and at idle, when it is very obvious, it changes if the clutch is pulled in.
His explanation is the spring(s) in the two piece primary drive gear are broken (page 9-25,26 in the Service Manual). The noise is not heard when you start a cold bike because the rpms are up, and with no load but the drag of the clutch there is no tendency to rattle. Let the rpms drop (as the bike comes off fast idle) and the drag decreases and the pulses from the engine cause the two pieces of the gear to make noise. This noise is loudest through the stethoscope on the part of the engine where this gear is housed (he could reach near the water pump), and lowest at the rear of the engine.
My questions: 1. Has anyone experienced anything like this? i.e. problems with the primary drive gear/springs.
2. Any other ideas? I questioned the drive chain for the water pump but he said once the bike is opened up this would be available for inspection as well. The bike shows no cooling problems.
3. Any comments suggestions would be welcome.
4. Does anyone have available for loan the clutch center holder, and gear holder 2.5? I would, of course, pay postage r/t.
P.S.'s My original post LINKY.
This independent mechanic has his own shop next to his house in Northeast rural Ohio. He works primarily on Goldwings, is AMI certified, and came highly recommended from a friend. I have not used him yet, but I'm impressed with his shop (clean, orderly, organized, crammed full of tools), his demeanor, his methodology, and willingness to take time to look at a stranger's bike. If you have a Goldwing or Valk, and don't want to work on it yourself, you might want to give him a try. I hesitate to recommend him here because I want him to be available to me when I need him - grin - not working on your bike. Oh yes, he works alone - no helpers. What you see is what you get. So, if you need a good mechanic, PM me.