Jack the front end of the bike off the ground. Tighten the adjusting nut until the front end is hard to turn. Next turn the handlebars back and forth, from stop to stop, through several cycles. Notice the front end becomes easier to turn. Back off the adjusting nut to a slightly loose fit, then tighten to about 9 ft-lbs torque. If the front end still wobbles after this (tire pressure good and tire in good condition, with no cupping, etc.) and the wobble occurs during deceleration, tighten the adjusting nut a bit more.

If you get a shimmy and more tightening does nothing to help, then suspect that the steering head bearings have shifted and the races are no longer parallel to the axis of the steering head. This is not unusual in HD bikes as they are relatively heavy. Modern bike head bearings tend to shift back and forth in the frame, especially on the heavier bikes, and this causes the bearings to become non-parallel. Any free play in the head bearings will compound this situation. This sets up torque forces that constantly try to correct themselves resulting in a shimmy, or head shake. The cause is not looseness; the bearings have shifted, and things ain't parallel. Pull the front end off and try to reseat the races in the frame neck.

Check the head bearings frequently IAW the service manual. Since these bearings do not move around like those on an axle, they tend to stay in one spot in relation to the race. Therefore every blow on the front end from road conditions tends to flatten the individual rollers or ***** ever so slightly. Over a period of time these flat spots can cause a condition whereby you point the forks straight ahead, and they tend to fall back onto the flat spot, causing a weave as you go down the road. If tightening the preload does nothing to correct the situation, suspect flat spots in the neck bearings.

By Alpha Samuel