I have a 09 "Dyna Super Glide" less than 5K miles.
When shifting 1,2 and 3rd gear rides smooth.
When shifting from 3 to 4th, a vibration starts, and continues in 5th and 6th.
Any idea of the problem?

I reported this at the first oil change, nothing said or done.
I took it back later as it seemed to get worse. The mechanic drove it and adjusted the belt. This did not correct the problem. I took it back again and asked the top mechanic to ride it. After his ride he told me “as long as I keep it under the speed limit it should be ok”.
This was not the reassurance I was looking for. The problem has been acknowledged but nothing done.

NEW: After reading articals about "6 speed trany problems" I think I have found the problem, I told the mech now at 8500 miles the vibration is so much worse, he asked if it was a 6 speed? I said yes, he replied yea thats probably it. "now that I have the extended warranty". We will see next week if they rebuild the trans.

 

The level of gall people are getting comfortable possessing is staggering. I hope he means that you should be able to sustain just under the absolute top speed of the machine's capability without encountering excessive vibration.

 

Are you keeping the engine speed at the same level once you get into 4th -6th? If you are letting it drop once you get into those gears for cruising speed you may notice more vibration. Try winding it up a bit more in each of those gears to see if it smooths out. I would also try another dealer, the definition of insanity is doing the samething over and over expecting a different result. If they haven't offered a solution yet they likely won't next trip!

 

Another thought, at the speeds you would be traveling in those gears it could be a tire balance issue.

 

Not to bust your chops, but are you familiar with engine lugging? Going to slow for the gear you are in. That's what sounds like to me. Just curious how long have you been riding the big twin?

 

Have them check the crank run out just because

 

they woulden`t lie to ya

 

Yes the engine speed is the same or higher RPMs
It's not "engine lug"

 

What is the engine speed?
You can run in first and second gear at 2,000 rpm but that same speed in 5th or 6th gear is a bit slow. I would think 2,800 to 3,000 rpm is a good test speed to check for vibration.
If the vibration gets worse at higher MPH speeds it probably a chassis problem such as wheel balance, bearings or chassis allignment.

Mike

 

out of balance tires or strange tire wear can feel that way