Table of Contents
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IH: Transmission & Final Drive
1957 - 1970 Sportster Four-Speed Transmission Specifications
Clutch
- Type: Dry - Multiple disc
- Capacity: 1900 in-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.
Primary Chain
- 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)
Starter
- Minimum clearance between clutch teeth on starter clutch gear and clutch with starter in up position: .040 in.
- Crankshaft endplay: .001 - .007 in.
Mainshaft Group
- 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.
- Third gear
- On shaft: .002 - .003 in. loose
- End play: .015 - .025 in. loose
Countershaft Group
- 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
- End play: .004 - .009 in.
- Clearance between clutch faces
- Countershaft low an third gear: .039 - .059 in.
- Countershaft second and third gear: .038 - .059 in
