Cummins/Onan — Removing and Installing Generator / Engine Assembly
Repair & overhaul · Generator/engine assembly
From a Cummins/Onan service manual covering: 5.5 HGJAA, 5.5 HGJAB, 5.5 HGJAC, 5.5 HGJAD, 5.5 HGJAE, 5.5 HGJAF, 6.5 HGJAA, 6.5 HGJAB, 6.5 HGJAC, 6.5 HGJAE, 6.5 HGJAF, 7.0 HGJAA…. Check it applies to your exact model before use.
Applies to: Cummins/Onan 5.5 HGJAD, Cummins/Onan 5.5 HGJAE, Cummins/Onan 6.5 HGJAE
Before you start
- Do not rest the generator/engine assembly on its fan shroud.
- Place blocks under the assembly when rested upside-down.
Procedure
- Drain the engine oil (genset will be turned on its side).
- Remove the two-piece control enclosure and disconnect the AC output leads.
- Disconnect the grounding strap at the generator/engine base.
- Disconnect fuel pump or fuel solenoid leads and fuel lines at the engine.
- Disconnect the engine exhaust outlet (or remove the muffler) as applicable.
- If separating engine from base, disconnect all engine wiring.
- Remove the two fail-safe bolts and lift the assembly off its mounting springs; rest it upside-down with blocks in place.
Tools required
- Blocks Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Fail-safe bolts 38 lb-ft (51 N-m)
Full service-parts list: Cummins/Onan 5.5 HGJAD →, Cummins/Onan 5.5 HGJAE →, Cummins/Onan 6.5 HGJAE →
Source: Cummins/Onan 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.