IH: Transmission & Final Drive

1957 - 1970 Sportster Four-Speed Constant Mesh Dry Clutch Transmission Specifications

Type: Dry - Multiple disc (7 friction plates, 7 steel plates between a steel backing plate and a front releasing disc)
- Back to front: Backing plate-S-F-S-F-S-F-S-F-S-F-S-F-S-F-Releasing disc
Capacity: 1900 in-lbs. (158.33 ft lbs.)
Set up Spring Pressure: 150 lbs.
- Spring adjustment: 3/16 in. from inner surface of spring tension adjusting plate to outer surface of spring cup flange
- Clutch bearing: .0005 - .002 in. loose
- (1970) - .0005 - .0029 in. loose
- Clutch cover: Must be leak proof. No gasket sealer
- Clutch release rod movement: .095 - .115 in.

	Year Model(s)	Engine Sprocket	Clutch Sprocket
Standard	1966 & Earlier XLCH 1967 & later XLH, XLCH	34 Teeth	59 Teeth
Optional	1966 and Earlier XL, XLH 1967 XLH, XLCH	34 Teeth	59 Teeth

Type primary: 3/8 in. pitch triple chain
Looseness: 5/8 to 7/8 in. slack (cold engine) - 3/8 to 5/8 in. slack (hot engine)

Minimum clearance between clutch teeth on starter clutch gear and clutch with starter in up position: .040 in.
Crankshaft endplay: .001 - .007 in.

Overall Gear Ratios are the number of engine revolutions to drive rear wheel one revolution.

	Year Model(s)	Transmission Sprocket	Rear Wheel Sprocket
Standard	1966 & Earlier XLCH 1967 & Later XLH, XLCH	20 Teeth	51 Teeth
Optional	1966 & Earlier XL, XLH 1967 XLH, XLCH	21 Teeth	51 Teeth

Clutch gear ball bearing in case: .0001 - .0012 in loose
Ball bearing on clutch gear: .0001 in. loose - .0009 in. tight
Clutch gear on mainshaft: .001 - .002 in. loose
Mainshaft right side roller bearing: .0006 - .0014 in. loose
Mainshaft end play: .004 - .009 in.
(1970) .003 - .009 in. with all axial play removed
Third gear
- On shaft: .002 - .003 in. loose
- End play: .015 - .025 in. loose
- (1970) .012 - .030 in

Countershaft end bearings: Retained needle roller bearing
Bearing fit on shaft ends: .0005 - .002 in. loose
Bearing fit in case: press
End play: .004 - .009 in.
Second gear
- On shaft: .001 - .0025 in. loose
Low gear
- On shaft: .0005 - .0016 in. loose
- End play: .004 - .009 in.
Drive gear
- On shaft: .001 - .0025 in. loose
- (1970) .0005 - .0030 in. loose
- End play: .004 - .009 in.
Clearance between clutch faces
- Countershaft low an third gear: .038 - .058 in.
- Countershaft second and third gear: .038 - .058 in.
- 1970
  - Mainshaft clutch gear and second gear: .043 - .083 in.
  - Mainshaft third gear and second gear: .043 - .083 in.
  - Shifter end play: .010 - .030 in