Engine Step 7 - Clutch Installation
Life's a bitch... Thank God there's Harleys...
After cleaning, inspection and re-assembly, we mounted the Harley clutch unit back into our 1973 Ironhead Sportster engine. Again we were able to re-use the original HD parts. Although it took quite some preparatory work, including the macgyvering of our own spring compression tool, the clutch installation was not as difficult as we thought.
We first cleaned, inspected and re-assembled the Harley Clutch Unit
Before putting the clutch release disc back in place we checked the length of the clutch springs (inner and outer). According to the table in our workshop manual the length of the clutch springs for Ironhead Sportster types 1971-1978 has to be 2.5" minimum. Fortunately ours were OK.
Clutch Spring Compression Tool
To get the clutch release disc back in place over the clutch plates requires quite a bit of force since the inner and outer clutch springs have to be compressed. No problema, señor! I mean, we have not spent all those years watching secret agent MacGyver on TV for nothing.
In the true tradition of our highly intelligent and optimistic action hero, we applied a practical combination of scientific knowledge and inventive use of common items, and we so macgyvered a fix to get those nasty springs compressed.
Our clutch spring compression tool consists of a sturdy old barn door hinge combined with the long bolts of our Harley starter motor which - by sheer coincidence, really - lay disassembled on another part of the workbench! These long bolts fit the bolt holes in the crankcase.
Clutch Release Disc Installation
As you can see in these pictures, we positioned the strip of steel (ex door hinge) diagonally over the clutch release disc, fixed the long bolts (ex starter) into the bolt holes in the crank case, macgyvered some spacers, then turned the nuts to compress the springs. Easy!
This photo shows the inside of the primary cover with the clutch mechanism reinstalled. We've also replaced the bearing of the pinion gear shaft.
Ironhead Engine Assembly Steps:
- Step 1 - Engine Case Assembly
- Step 2 - Oil Pump
- Step 3 - Cam Gears and Cover
- Step 4 - Installation of Primary Chain and Sprocket Wheels
- Step 5 - Fixing of the Compensating Sprocket
- Step 6 - Clutch Unit: Parts Cleaning and Preparations
- Step 7 - Clutch Release Disc: Installation Using Spring Compression Tool
- Step 8 - Startmotor: Cleaning and Inspection
- Step 9 - Startmotor and Bendix: Install and Test
- Step 10 - Primary Cover Back in Place
- Step 11 - Main Shaft Rollerbearing
- Step 12 - Oil Seal and Sprocket