Ok I did do a search but did not find my problem.
I have a 09 ultra, when applying the rear brake there is a Real bad vibration , but only seams to do it when 2 up. I am talking real bad feels like someone is hitting the pass left side floor board with a hammer and the brake pedal goes up and down. The first trip the dealer did a download for the abs, no better. The second trip the dealer claimed nothing wrong, I brought it back the 3rd day and got the manger involved he went on a test ride and said there is a deffinate problem, the mechcanic drove it and said *uck thats bad. So they determined it was the iso drive and had to order parts. Brought it back installed Iso got a little better but still there. They checked swing arm bushings ,motormounts, brakes, and frame. So they called harley tech and they said try a new front tire. Now I really dont think this is the cause but I will take the tire

Also the mechanic founds this happen not only at braking but also if you bring the rpms up and let off, so it looks like this is not a brake problem.

Sorry for the long post but this is frustrating this is my wifes bike and I dont trust it.
Any ideas, thanks Al

 

I would think that iso drive would vibrate all of the time, not just when braking.

I may be asking the obvious, but have they checked for a warped rotor?

 

This will be interesting. My 09 Ultra does the same thing. have not gone bach to the dealer about it yet.

 

Yes the rotor was checked, this is a really weird problem, it feels more like a frame issue then a wheel. and the fact it is much worse 2 up realy has me confused.The strange part is why it feels so bad on the left pass floor board. I will keep this updated.

 

If my bike was acting like yours, I would take it to the dealer and leave it. Tell them to call me when they find the problem, period. It could very well be a saftey issue as bad as you say it is. Let them get HD involved in it.

 

I agree with the saftey issue, I went up to the dealer and told them I wanted to bring it back untill it was fixed, he assured me that it was safe, I asked how do you know if you dont know the problem. I told my wife to let it sit in the garage until the new get installed this week. I will tell them to keep it until this is fixed. Thanks Al

 

Sounds like the real wheel is being driven out of alignment (braking, accel). Swing arm?

With the rear wheel out of alignment or flexing, the brake rotor would track the error - you'd feel it in the pedal braking.

 

ok last night I jacked the bike up and checked everything I could to the best ability. Swingarm and wheels bearings seem ok. Dose not look the the rear tire has moved. I checked the whole frame and also looked for loose bolts.

I took it for a ride and it really feels like its coming from the left of the trans or underneath. Its much worse when 2 up. If I brake or let off at higher rpms it vibrates. Almost feels and sounds like the front gear on the belt is skipping ?. maybe a trans issue?.

 

Check the rubber bumper in the Jiffy Stand. If it is missing or out of place, the Jiffy Stand will make a lot of racket and vibration as it beats against the frame. I would also check that the heat shield in front of the left muffler is tight.

 

check the "dog bone" on the underside of the frame....on the 09 and 10's (new frame design) the dog bone is very close to the tranny/oil pan....if the bike has been lifted in the dog bone area....it could have been distorted and now bumps on the tranny/oil pan.

dont ask me how I know