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I was riding around today and cming to a stop i rolled off the throttle and a very sudden vibration occured. you can feel i through the entire bike. it happens when i roll off the throttle. it doesnt matter what speed. it feels similar to transmission drag in a car. if you hae ever towed a load ad had to brake suddenly, the truck shakes and vibrates, kind of an anti lock brakes feel. does anyone know what this could be?
 

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Iron Butt, SS2000
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Have the front motor mount checked.
 

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Were you on the front brake at all when you experienced the vibration? If so, you may be suffering from the famous front end clunk. Correct torquing of the steering head bearing adjustment nut and the top stem nut may be needed. If it is an 06 or later Dyna, Harley has a new washer to replace the OEM washer under the top stem nut. The part number for this washer is 45740-07. This replacement nut is per service bulletin #M-1215a.
 

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vibe

I had a vibration at about 1500-1800 rpm. After a while it would go away....turns out it was a loose compensator nut that would back off and then retighten after acceleration....
 

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on mine (07 Dyna) the clevis pin that mounts the kickstand was hitting a case bolt when you used the rear brake thereby telegraphing the engine vibe to the frame. My dealer cured it by installing the pin backwards.
 

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I was riding around today and cming to a stop i rolled off the throttle and a very sudden vibration occured. you can feel i through the entire bike. it happens when i roll off the throttle. it doesnt matter what speed. it feels similar to transmission drag in a car. if you hae ever towed a load ad had to brake suddenly, the truck shakes and vibrates, kind of an anti lock brakes feel. does anyone know what this could be?
sounds very similar to what I felt when I discovered I had a broken rear motor mount. Mine was worse w/ a passenger.
 

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I was riding around today and cming to a stop i rolled off the throttle and a very sudden vibration occured. you can feel i through the entire bike. it happens when i roll off the throttle. it doesnt matter what speed. it feels similar to transmission drag in a car. if you hae ever towed a load ad had to brake suddenly, the truck shakes and vibrates, kind of an anti lock brakes feel. does anyone know what this could be?
broken rear or/and front motor mount
 

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Wierd vibration very distinct

Hi, I have the same thing going on with my bike, when I'm slowing down to stop and I close the throttle I get a shaking of the whole bike as it decelerates. The shaking slows down as the engine slows. When I down shift and let the clutch out it does it again. Seems like it started doing it after the 1k service was done. They also did the stage 1 air cleaner and download at the same time. I can't think of anything done during this service that could have anything to do with the vibration? Bike is 08 Street Bob all stock besides the stage 1 and Khrome Werks slip on mufflers.
 

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What is a compensator nut?
Scott,

The compensator nut is the part (the nut) that attaches the front sprocket to the motor crank.

When a cylinder of a v-twin fires there is a very strong power pulse. To keep from shaking the bike and rider apart these pulses have to be "smoothed" out. Harley does this by NOT solidly attaching the front sprocket to the engine - they use a "compensating sprocket".

A crank shaft extension, double sprocket, sliding cam, and a stiff spring together form a "compensating sprocket". When a cylinder fires, the power stroke is smoothed out by the action of the compensator cam and springs.

The compensator nut is what holds the compensating sprocket assembly on the crank.

There are a LOT of forces acting on this nut and sometimes the nut loosens up. A loose compensator nut results in a compensating sprocket that can move laterally on the crank. A loose compensator nut therefore is one potential source of engine vibration.

Harley-Davidson issued service bulletin a while back that changed the procedure for tightening the compensator nut, after a spate of bikes had problems with this nut working loose.
 

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I have the same problem. Only happens at slow speeds on decel. Seems to be only in the front end,like a wobble more than a vibration. I thought it might be the front tire being worn, but I still have tread. How do I check the motor mount?
 

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thetryal,T
Trying not to get long winded here……so here goes,
I’ve got a similar condition with my 07 FXDWG. Since I’m coming from a bike with a solid motor mount, it’s hard to get a point of reference. I really noticed the vibration when I went to an aftermarket set of mirrors. The things are shaking so much I can barely see cars behind me. After reading another thread on this forum I had the dealer check my front motor mount. It appeared strange that with the mount bolts out, and the engine lowered to the front frame mount, the mounting holes were off by a full hole. So, I had them raise the motor until the mount holes and the frame holes were aligned. Then this left me with approx. 1/4” space between the two, which I used solid spacers to fill. All this being said, when I made the next ride the vibration was still there. When riding down the road at 70mph. I can pull in the clutch and as the motor winds down the vibration is all but gone. This tells me it is definitely being induced from the engine. The dealer has told me this is inherent with a Harley. This may be true, however when I questioned why this much vibration would be in the frame at cruise speed with a rubber mounted engine he basically couldn’t give me an answer. Still trying to find the “silver bullet“ myself.
 

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Scott,

The compensator nut is the part (the nut) that attaches the front sprocket to the motor crank.

When a cylinder of a v-twin fires there is a very strong power pulse. To keep from shaking the bike and rider apart these pulses have to be "smoothed" out. Harley does this by NOT solidly attaching the front sprocket to the engine - they use a "compensating sprocket".

A crank shaft extension, double sprocket, sliding cam, and a stiff spring together form a "compensating sprocket". When a cylinder fires, the power stroke is smoothed out by the action of the compensator cam and springs.

The compensator nut is what holds the compensating sprocket assembly on the crank.

There are a LOT of forces acting on this nut and sometimes the nut loosens up. A loose compensator nut results in a compensating sprocket that can move laterally on the crank. A loose compensator nut therefore is one potential source of engine vibration.

Harley-Davidson issued service bulletin a while back that changed the procedure for tightening the compensator nut, after a spate of bikes had problems with this nut working loose.
This nut loosens more oftem on 03 and later engines. It is directly attributable to the crankshaft bearings that are now used. Also the threads on the crank don't go far enopugh, so a shim or milled nut is needed to do the job correctly. there is also a new torqueing process to use.
 

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Thanks 84fxrp, great explanation. I will consult my shop manual and check the compensator nut torque. It is amazing how many dyna owners have the excessive vibration complaint and how H.D. has managed to avoid doing anything about it
 

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Thanks 84fxrp, great explanation. I will consult my shop manual and check the compensator nut torque. It is amazing how many dyna owners have the excessive vibration complaint and how H.D. has managed to avoid doing anything about it. Scott
 

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compensator...

Is there an echo in here? :^)

My indy found my compensator loose with no evidence of any locktite. He used locktite and torqued to spec..

Sometimes I think the "super" primary lubricants can penetrate so well that the surfacants actually dissolve the locktite over time....
 

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I've got a 98 FXD thats smooth as glass at all speeds. Motor shakes like a banshy in the frame at idle though! So it is not inherent in this model. At least not in the Evo's. I would look at motor mounts. If enough oil from changes gets on the front motor mount, it very quickly destroys the rubber. I wish I could find a urethane mount for the Dynas but have had no luck. I actually cannot find many parts for my 98 anymore. Obsolete I guess at 10 years old.
 

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Iron Butt, SS2000
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We have not heard back from thetryal on this. I wonder if it's been properly diagnosed. I mean really, the guy asks for help and doesn't come back with an update? Reminds me of R Lee Ermey in Full Metal Jacket. "Pile, you don't have the common courtesy to give a guy a reach around!" :confused:
 
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