Hercules — Piston and Connecting Rod Installation
Repair & overhaul · engine
From a Hercules service manual covering: D-1500, D-1700, D-2000, D-2300, D-3400, De3000. Check it applies to your exact model before use.
Applies to: Hercules D Series engine
Procedure
- Measure cylinder bores and check piston fit without rings.
- Install new piston rings whenever a piston is removed.
- Check ring gap: 0.010 to 0.020 inch.
- Assemble piston and connecting rod with piston pin and retaining rings.
- Install piston rings with expander tool; stagger ring gaps.
- Apply lubricating oil to cylinder bores, pistons, rings, and crankshaft journal.
- Use ring compressor to install piston and rod assembly from top of cylinder block.
- Install upper bearing in connecting rod and pull assembly onto crankshaft journal.
- Check bearing clearance with plastic gauge; required 0.001 to 0.003 inch for new parts.
- Install connecting rod cap and tighten bolts to 68 to 72 foot-pounds.
- Check connecting rod side clearance: 0.005 to 0.012 inch.
- Install remaining pistons and connecting rod assemblies.
Tools required
- Micrometer Amazon
- Cylinder bore indicator Amazon
- Ring compressor Amazon
- Plastic gauge Amazon
- Torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Ring gap 0.010 to 0.020 inch; connecting rod bearing clearance 0.001 to 0.003 inch new; connecting rod bolts 68 to 72 foot-pounds; side clearance 0.005 to 0.012 inch.
Source: Hercules service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.