Expert: Collin Bradham - 10/16/2006

Question
I am original owner of 1996 HD FXD 11000mls About 6mos ago,at 8000 mls developed  vibration ,between 2500 and 3000 rpm, from rear  most noticeable in 5th gear,after warm-up. It almost felt like rear tire  had a flat spot.Took to local HD shop, they said possible motor mts.Replaced front and rear,still there.Back again,new rear tire,self adjusting primary chain kit,double checked wheel balance and made sure drive belt adj. to spec.,all 100%,STILL THERE.HD tech. said all DYNAS have vibrations,loosened drive belt and told me that it was all he could do.Took bike to local bike shop with a Dyno,put on dyno, ran bike to warm-up,and at 2500/2800rpm, in 4th and 5th gear ,you could actually see and feel back of bike ,fender license plate etc. SHAKE.Local guy said he never saw this before,but possible clutch hub or trans or axle bearing.because it only happens after warm-up he is baffled .Bike runs 100%on dyno ,no misses or noises under load,good clean plugs etc.Before I start a tear down I would appreciate another opinion/advice..THANX ..DAC  

Answer
It would almost have 2 b a clutch hub or transmission issue.  I don't know how but it's almost if something has bent or a gear has become loose.  Open your primary 1st and manually try to shake belt, and gears to c if there's any play in them.  If so, that is most likely your issue.  Same with inside tranny, but I sure hope u don't have 2 go that far!  Is it at all possible u have bent your rear wheel?  Are your bearing good?  Lift the rear end and check for side to side play in the rear end, and then up and down.  If there's play it won't take any muscle 2 find it.  Good luck and let me know!