Drive Adjustment for Big Twins
1. At the lower strand, position "A",
mid-way between transmission sprocket and rear wheel sprocket, apply 10 Ibs. of upward
force on lower span of rear belt. Harley-Davidson has a BELT TENSION GAUGE (Part No.
HD-35381) to help.
|Set belt tension a the tightest rotational point on the
|The adjustments should be done when the bike is cold.|
|The adjustments should be made with the weight of a rider
on the bike.|
2. Measure belt deflection "B" several times, each time
with belt moved (by rotating rear wheel) to a different position on sprockets. With
sprockets rotated to tightest belt posi-tion, belt deflection "B" (measured at
position "A") should be 5/16-3/8 in.
1. Loosen rear axle nuts.
2. Measure each side from the flat to the end of the
swingarm, to be sure rear axle is correctly located.
3. Turn axle adjuster nuts (metric) on each side of
swing-arm to adjust belt deflection.
a. Turn clockwise to decrease deflection (increase tension).
b. Turn counterclockwise to increase belt deflection (decrease tension).
Turn each adjuster nut exactly the same number of turns to
maintain rear wheel alignment.
5. Tighten axle nut to 60-65 ft-lbs.
Keep dirt, grease, oil, and debris off the belt and
sprockets. Clean the belt with a rag which is slightly damp with light cleaning agent.
All belts must be handled carefully to prevent bending
stress. The belt must never be formed into a loop smaller than 5 inches in diameter and
never be bent backwards. Sharp bending can weaken the belt and lead to premature failure.
Old belts that are taken off a bike during repairs must be reinstalled so they rotate the
Tricks of the trade
With a high horsepower engine, it is better to have the belt a little tight rather than
loose. A loose belt will break much more readily than a tight one. Most people do not
tighten the belt to its proper tension. If you plan on "racing" or hot rodding
your bike, invest in a Harley-Davidson BELT TENSION GAUGE (Part No. HD-35381).