Special Tools

Description	Part Number	Qty.
BELT TENSION GAUGE	HD-35381-A	1

NOTE

Always use BELT TENSION GAUGE (Part Number:HD-35381-A) to measure belt deflection. Failure to use tension gauge may cause under-tensioned belts. Loose belts can fail due to "ratcheting" (jumping a tooth) which causes tensile cord crimping and breakage.

Check deflection:

As part of pre-ride inspection.
At every scheduled service interval.
With transmission in neutral.
With motorcycle at ambient temperature.
With motorcycle upright or on jiffy stand with rear wheel on the ground.
With the vehicle unladen: no rider, no luggage and empty saddlebags.

WARNING

To prevent accidental vehicle start-up, which could cause death or serious injury, remove main fuse before proceeding. (00251b)

Disarm security system. Remove main fuse. See Maintenance and Lubrication → Fuses and Relays.
Shift transmission to neutral.

NOTE

When adjusting a new belt, rotate rear wheel a few revolutions prior to setting the tension.

See Figure 1. Measure belt deflection using BELT TENSION GAUGE (Part Number:HD-35381-A):
1. Slide O-ring (4) to zero mark (3).
2. Models equipped with belt deflection window: Fit belt cradle (2) against bottom of drive belt in line with belt deflection window.
3. All other models: Fit belt cradle (2) against bottom of drive belt halfway between drive pulleys.
4. Press upward on knob (6) until O-ring slides down to 4.54 kg (10 lb) mark (5) and hold steady.
Measure belt deflection:
1. Models equipped with belt deflection window: See Figure 3. Measure belt deflection as viewed through belt deflection viewing window while holding gauge steady. Each deflection graduation is approximately 1.6 mm (1/16 in).
2. All other models: See Figure 2. Measure amount of deflection (4) while holding gauge steady.

NOTE

Set to the lower (tightest) specification if the belt has less than 1,600 km (1000 mi).

Compare with specifications. Refer to Table 1. If not within specifications, see a Harley-Davidson dealer.
Install main fuse.

Table 1. Belt Deflection

MODEL	IN	MM
FLHX, FLHXS, FLTRX, FLTRXS, FLHRXS and FLHTKL * (low profile shock absorbers)	1/4-7/16	6.4-11.1
All except FLHX, FLHXS, FLTRX, FLTRXS, FLHRXS and FLHTKL * (standard shock absorbers)	3/8-9/16	9.5-14.3
* Includes model variations such as CVO

1	Belt tension gauge
2	Belt cradle
3	0 lb (0 kg) mark
4	O-ring
5	10 lb (4.5 kg) mark
6	Knob

Figure 1. Belt Tension Gauge

1	Transmission sprocket
2	Rear wheel sprocket
3	10 lb (4.5 kg) of force
4	Amount of deflection

Figure 2. Checking Belt Deflection

1	Drive belt
2	Deflection graduations (Approx: 1.5 mm (1/16-in)

Figure 3. Belt Deflection Window