Coming off an '04 FLHT to a new '06 FXDI, I had always felt that the Dyna vibrated more than it should. I had always figured it was due to having a pampered butt from the big E-Glide, until I went on a Harley demo ride last week. I took a Dyna Wide Glide out for a spin and I could not BELIEVE how smooth it was in comparison to my Super Glide. I questioned the sales guy and service tech at my dealer after the ride and they both said that other than ride quality there shouldn't be any difference between the two, as they had the same motor and frame. The service rep mentioned they had already replaced a few lower front motor mounts on '06 Dynas, including one of the demo bikes the day before. All of them had low miles, much lower than the 8,300km on mine. So the service tech sent a mechanic out to look at my bike, he crawled behind the front wheel to take a look and immediately said "Yep, it's shot". So they ordered one in and replaced it last Thursday, under warranty.

BIG DIFFERENCE! The original motor mount must have been shot at time of delivery, because the bike has never run this smooth before. I have put over 1,000km on the bike with the new mount and it has been a much more pleasant riding experience. The service rep has been in touch with Harley and right now they don't have an answer as to why there have been premature failures on these mounts, apparently there have been quite a few so far. So for all '06 Dyna owners, get the lower front motor mount on your bike checked. You never know.

 

Happy 4th bro! My wifes new street bob had the same problem! I told the dealership that it vibrated excessivly and said it was normal! I called BS. I ended up raisen enough hell with them that they replaced the front mount. WHAT A DIFFERENCE! I then told them if the front one was collapsed and made that big of difference, they should change the rear one. They did and the bike rides WAAAAYYYY better! glad to hear you got it fixed! Enjoy the rides to come.
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Thanks for the heads up Gummiente.

mud

 

Having the engine mount preloaded from the factory is most likely the cause of engine mount failures. When I removed my vapor canister my frame mount pulled forward and the engine mount also pulled away into a stress free condition. I had a jack under the engine so that I could screw the bolts in by hand with no resistance which gave me a 3/8" gap that I shimmed with washers. Then I came across the below post and it seems to be a common problem on rubber mounted bikes.


FXD Vibration Problem Cured - $10 Materials

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Sorry for the long post, but I have cured my Dyna's vibration problem for about $10 in materials and I thought others might benefit from my approach.

I have a 2005 FXDI with a HD 95 inch Stage I kit.

Like some others on the Forum, my bike had, what I consider, excessive engine vibration transmitted to the handlebar, foot pegs, and seat. The vibration was especially evident below 3000 rpm. At idle, the handlebars jumped around excessively.

I followed the Service Manual procedure for vehicle alignment in an attempt to reduce the vibration. Alignment includes loosening (but NOT removing) ALL the motor mount attachment bolts, and then running the motor for 5 seconds during which allow the mounts to align themselves to the frame. The motor mount attachment bolts are then re-torqued to spec. The procedure helped a little, but did not cure the problem. I also looked at other changes that might address the vibration problem such as a Bar Snake, different length handlebars, handlebar mount bushings, etc. All these are Band-Aids on the fundamental problem of too much vibration.

A few weeks later I was thinking about the motor mounts and the alignment procedure and was struck by the cause/cure of the vibration problem. Any elastic motor mount, like the Dyna's, has a limit to how much vibration it can absorb. Engine movement in excess of this limit is transmitted through the frame to the handlebars, foot pegs, seat, etc as vibration.

What struck me was that when I did the alignment procedure and the mounting bolts were LOOSE, there was a gap between the mount and the frame. Tightening the mounting bolts caused my front motor mount to be PULLED forward to the frame as the mounting bolts were tightened. I noticed that when the mounting bolts were torqued, the frame was also deflected somewhat.

THE ELASTIC TRAVEL OF MY MOTOR MOUNTS WAS LARGELY USED UP JUST BY BOLTING THE MOTOR MOUNT TO THE FRAME.

Any movement of the motor would not be absorbed by the mount as the elasticity of the mount is already used up before the motor is even started. Hence any engine movement is transmitted to the frame and is felt as a vibration. This would also explain premature failure of Dyna motor mounts as they are under stress to begin with.

My solution was to shim the gap between the UNSTRESSED front motor mount and the frame. THE ENTIRE INHERENT ELASTICITY OF THE MOUNTS IS NOW AVAILABLE TO ABSORB ENGINE MOTION. MY VIBRATION PROBLEM WAS GONE!

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Try this site for photos: http://spotks.blogspot.com/

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Picture shows the gap between the unstressed front motor mount and the frame of my bike as it is almost 0.2 inches. The solution is to shim this gap.

Picture shows my test where I used washers as shims to test my theory. Result - excessive vibration is GONE. The bike is very smooth and the handlebars don't jump around at idle.

Picture shows the final result. I cut some brass shim stock to fit and used longer bolts to accommodate the shims thickness.

Picture shows a scissors jack and block of wood I used to hold the engine up when I had the mounting bolts removed. I had my wife steady the bike and hold it level while I worked on the mount.

 

I had the same problem and had the front one replaced at the 1k service. So far so good since with my 5k insp.

 

Thanks WS6. I can't believe I missed this post. I have been following this thread for a long time waiting for someone to try the procedure you did before they shimmed the mount so that there was a comparison and here it is on the 4th post. Your pictures and attention to a very detailed description are very professional and my compliments to you.
You have made it clear that a person needs to do both procedures.
Cheers.