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 saddlebags (if equipped) empty.

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.
See Figure 1. Obtain BELT TENSION GAUGE (Part Number:HD-35381-A).

NOTE

Gauge is available from an authorized Harley-Davidson dealer.

To use the belt tension gauge:
1. Slide O-ring (4) to 0 kg (0 lb) 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 half-way between drive pulleys.
4. Press upward on knob (6) until O-ring slides down to 4.5 kg (10 lb) mark (5) and hold steady.

NOTE

Measure belt deflection with motorcycle unladen and upright or on jiffy stand with rear wheel on the ground.

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 1.59 mm (1/16 in).
2. All other models: See Figure 2. Measure belt deflection (4) while holding gauge steady.
Compare with specifications listed in Table 1. Adjust as necessary.
Install main fuse.

Table 1. Drive Belt Deflection

VEHICLE	FXSB, FLSTN, FLS, FLSTFB*	OTHER MODELS
Upright or on jiffy stand without rider or luggage	6.4–7.9 mm (¼–5/16 in)	14.3–15.9 mm (9/16–⅝ in)
* FLS (DOM/CAL/CAN/HDI/JPN configurations) ** FLSTFB (DOM/CAL/CAN/JPN/AUS configurations) Refer to Identification → Vehicle Identification Number (VIN) → Harley-Davidson VIN Breakdown: 2015 Softail Models to determine vehicle configuration.

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