i dug up an old post earlier and seen that alot of people
have the same problem as me.its a vibration or shake at
65 or so that you can feel in the gas and brake pedal
armrest and seat.some mentioned its from the exhaust
i thought it was wheel balancing but it does it with all
3 sets of wheels i have.i just bought one of those exhaust
balancers someone mentioned but havent put it on yet.
hopefully it will help.has anyone fixed this for sure or know where
its comin from?

 

The exhaust dampener that you bought will have little effect on the vibration you're chasing, I believe. The dampener is for the exhaust system vibration issue that occurs around 3000 rpm or 90 mph. You can test for this in neutral or in Park by revving to 3000 rpm. If you get a thrumming, the dampener and exhaust system neutralization will solve it.

The 65 mph shake is not exhaust related in my opinion. It was changed around by my switching to a different driveshaft (still stock type) but it only changed when it happened. My truck used to start shaking only when the temperature got to 65 or 70 deg. F. Below that it was fine. The driveshaft change only lowered the temperature at which it occured.

Since the '01's were the first trucks to come with an aluminum driveshaft, I believe that it is the source of the problem. Not a dimensional or out of balance issue, but a changing shape with temperature issue. My only regret is that I didn't try a steel driveshaft to test my theory. Also note that the '02 Harleys are using a two piece driveshaft in aluminum. (Longer length I know!)

Just my $0.02.

 

ill try the dampener since i got it already,
my next step was to rebalance the driveshaft
i also was thinking of taking the shackles off,
but i guess that aint it either.
so would a 99-00 driveshaft be a direct fit?
what is so much better about the aluminum
anyway besides the free 65mph massage?

 

in my 00 i get not a vibration but more of a wobble @75-80

 

I had that problem on my 99 black L few months back, my Stock F1's were bald and wheels not balanced right so everyhitng shoook at 60+ got toyo proxoes for 275 a pop and all better...