Replacing 5 speed stock transmission with a 6 speed

[silentflyer]

Probally cheaper to change out the cam and get more torque out of the engine...just decide wher you want the power band

 

[bigironjim]

Okay, on this 6 speed in the 5 speed case I see... 6 speed "direct drive" (1 to 1 in 6th I take it?) and Overdrive 6th, also a direct drive kit that includes a compensating sprocket, larger I presume, primary chain and a large inventory of other parts that claims to lower engine rpm at cruising speed. But the pricing is all over the place.
My bride rides an '06 Heritage that when we are traveling highway speeds, 70 plus, the engine vibration is excessive, and makes for an uncomfortable ride. Looking for input BEFORE I spend the money this fall.
Thanks in advance.

 

[TQuentin1]

My bride rides an '06 Heritage that when we are traveling highway speeds, 70 plus, the engine vibration is excessive, and makes for an uncomfortable ride. Looking for input BEFORE I spend the money this fall.
Thanks in advance.

The '06 Heritage is a softail with a counterbalanced version of the Twin Cam engine instead of the regular Twin Cam engine used in the Touring (like your Road King) and Dyna models. Before spending money on the tranny for her bike, I suggest that you figure out why it has the vibration problem. I would start by checking the engine pinion shaft runout. Excessive runout will indicate that the driveshaft has scissored. This will not be corrected by changing out the tranny.

If that checks out OK, then has there been any work done to the engine counterbalance system that might have reassembled it incorrectly?

In my mind, this is job one BEFORE considering work on the tranny.

Cheers,

TQ

2007 Harley Davidson 96 Twin-Cam Pinion Shaft Runout - YouTube

 

[Jack Klarich]

This is the balancer T Q is talking about

 

[TQuentin1]

This is the balancer TQ is talking about

That's it!!

I don't know if it is possible, but if the balancers can be assembled with one or both of them off a tooth or more, you would have a real vibration problem as the rpms increase.

But if no one has been into this system, I would look for other things that affect vibration first (like tire balance, tire pressure, cupping, alignment, even drive belt tension, etc.). These are FAR easier to check and fix. If no one has been into the counterbalancer system, and this problem has developed over time (not there from the beginning), I would not start here!!

Cheers,

TQ

 

[Jack Klarich]

Keep in mind the reason for the counter balancers is the way the motor is mounted to the frame. Check ALL mount bolts first, pay attention to the upper mount
A 6 speed will lower your RPM, but not enough to offset the vibration you are talking about IMO