Screamin' Eagle Race Clutch
J036022007-05-10
GENERAL
Kit Number
37970-03A
Models
1999 though 2006 Twin Cam models (does not fit '06 Dyna's or '07 Twin Cams) motorcycles and '90 - '99 1340 Evolution model motorcycles (does fit models with Hydraulic clutch)
Additional Parts Required
For 1994-1997 Evolution models: Clutch shell (Part Number 37707-98) and Rod Adjuster Screw (Part Number 37090-98) must also be installed.
For 1990-1993 Evolution models: Clutch shell (Part Number 37707-98), Rod Adjuster Screw (Part Number 37090-98) and Starter (Part Number 31553-94) or modification to starter extension shaft to fit Pinion Gear (Part Number 31342-93), Bushings (Part Number 33445-94A) and (Part Number 33446-94) sleeved to fit in primary or Primary Housing Assembly (Part Number 60663-95) must also be installed.
WARNINGRider and passenger safety depend upon the correct installation of this kit. Use the appropriate service manual procedures. If the procedure is not within your capabilities or you do not have the correct tools, have a Harley-Davidson dealer perform the installation. Improper installation of this kit could result in death or serious injury. (00333b)
NOTE
This instruction sheet references Service Manual information. A Service Manual for your model motorcycle is required for this installation and is available from a Harley-Davidson Dealer.
Kit Contents
Table 1. Kit Contents
Description (Quantity) | Part Number |
|---|---|
Locknut (6) | 7682 |
Center, clutch assembly | 37957-98 |
Set, friction and spacer discs | 37980-03 |
Studs (6) | 37959-98 |
Spring caps (6) | 37954-98 |
Clutch springs (6) | 45884-98 |
Pressure plate | 37953-98 |
SE derby cover gasket | 25477-04 |
INSTALLATION
NOTE
Refer to applicable Harley-Davidson Service Manual for installation of clutch, but note the following exceptions:
NOTICE
Do not reinstall the damper spring and/or damper spring seat with this kit. Doing so will affect the stacked height of the clutch discs. Failure to comply could result in premature clutch failure and possible engine damage. (00459c)
NOTE
The derby cover gasket must be replaced each time the derby cover is removed.
| 1. | Use derby cover gasket supplied in this kit. | |||||
| 2. | See Figure 1. The clutch assembly replaces the original equipment single diaphragm spring with six coil springs. The coil springs allow for easy adjustment of clutch force. The total clutch force is adjustable from zero to 500 pounds. The force is increased or decreased by turning the locknuts (1) which retain the coil springs to the pressure plate. | 
Figure 1. Clutch Components Installed | ||||
| 3. | Based on the engine's torque output at the crankshaft, determine the total spring force and spring height required (See Spring Force Calculations Table.). | 
Figure 2. Measuring Spring Height | ||||
| 4. | See Figure 2. Tighten locknuts (1) in a cross-wise bolt pattern to the spring height (2) as determined in step 2. In all cases, the adjustment height must be equal on all six coil springs. | |||||
| 5. | The clutch spring height (2) and cable free play must be checked and adjusted periodically to compensate for friction plate wear. These adjustments are especially important during the friction plates break-in period. Also, look for signs of clutch slippage and increase the total spring force accordingly. NOTE On 1996 and earlier 1340 models (with 24 tooth engine sprockets) the total spring force must be increased from the chart below by 4%. |
SPRING FORCE CALCULATIONS TABLE
Table 2. Models
Engine Torque @ Crank, ft-lbs | Total Spring Force (lbf) | Spring Height (inches) |
|---|---|---|
50 | 154 | 0.366 |
60 | 185 | 0.356 |
70 | 215 | 0.345 |
80 | 246 | 0.334 |
90 | 277 | 0.324 |
100 | 309 | 0.313 |
110 | 340 | 0.302 |
120 | 371 | 0.291 |
130 | 402 | 0.280 |
140 | 433 | 0.269 |
150 | 464 | 0.259 |
160 | 495 | 0.248 |