[dingdong]

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Developed a heavy thumping vibration ( Not a tinny feel as if plastic rattling) when decelerating that is getting worse. Especially noticable at higher speeds say 75mph. At lower speeds below 60 it isn't quite as noticable. The vibration is something that I feel not hear. If I ease off the throttle I can minimize the feel. High frequency, I'll compare the frequency to a machine gun. I've had cars with worn u-joints that felt similar to this. Any ideas or experience with this? Bike has 46k miles.

 

[AVA AUTO TECH]

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Are the calipers, slider bushing hanging (seizing). Tire pressures?. Does it do it in every gear? Just some questions to throw at you. Tony:waving:

 

[GLGREZMONKI]

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You may be right on thinking it is the u-joint. The symtoms of a failing u joint can be just as you describe. To check it carefully pull back the rubber boot at the right rear of the engine ( Be careful not to tear it) rotate the rear wheel both in and out of gear and check for looseness or any other adverse movement in the ujoint. It is not really difficult to change the ujoint on a 1500, if that is, in fact ,the problem,but you do need a pivot bolt locknut tool so that it can be retorqued properly..........GM

 

[dingdong]

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For some reason the brakes hadn't occured to me. I have noticed that the front brakes seem to make some noise when I backup. I'll check them out as well as the u-joint.

 

[Big John .25]

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Prolly the u-joint, or the shaft splines get some play in them. It happens from a higher speed when the U-joint is in a no load situation. a bit of brake or a bit of throttle eliminates the vibrations. If when slowing down instead of shutting the trottle completely , keep the throttle just bit open to some torque on the shaft and the u-joint.d see if the vibrations mostly goes away.

 

[dingdong]

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Big John .25 wrote:

Prolly the u-joint, or the shaft splines get some play in them. It happens from a higher speed when the U-joint is in a no load situation. a bit of brake or a bit of throttle eliminates the vibrations. If when slowing down instead of shutting the trottle completely , keep the throttle just bit open to some torque on the shaft and the u-joint.d see if the vibrations mostly goes away.

Braking doesn't seem to help but keeping the throttle open slightly does almost eliminate the vibration. Havn't had time to check anything yet. Thanks for replys.

 

[dingdong]

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Okay! Found the cause of the vibration. Turned out to be one of the mufflers was loose. Had a rear tire installed before our last trip and evidently they leftone bolt out and the other loose thatclamps the front of the muffler. Only thing holding was the rear hanger bolt. It was vibrating against the trailer hitch bracket. Just happened to see it when inspecting the u-joint. Thanks for the help.

 

[DBohrer]

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GLGREZMONKI wrote:

You may be right on thinking it is the u-joint. The symtoms of a failing u joint can be just as you describe. To check it carefully pull back the rubber boot at the right rear of the engine ( Be careful not to tear it) rotate the rear wheel both in and out of gear and check for looseness or any other adverse movement in the ujoint. It is not really difficult to change the ujoint on a 1500, if that is, in fact ,the problem,but you do need a pivot bolt locknut tool so that it can be retorqued properly..........GM

GM, When you mention the pivot bolt locknut tool, are you referring to the swing arm? If so, the universal joint and boot can be changed without removing the right side swing arm bolt. BTDT.