The Cummins/Onan QSB5-G5NR3 is a 4.5 L turbocharged and charge air cooled engine rated at 1800 rpm. It powers generator sets from Terex, including the T120. It holds 8.5 L (2.2 gal) of coolant.
Also known as: Cummins QSB5-G5NR3
Part of the Cummins/Onan QSB5 engine family — 15 variants share parts & fitment.
| Coolant capacity | 8.5 L |
|---|---|
| Displacement | 4.5 L |
| Aspiration | turbocharged and charge air cooled |
| Rated speed | 1800 rpm |
How to read your Cummins/Onan engine serial & model number →
Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan QSB5-G5NR3.
| Part # | Description | Category |
|---|---|---|
| 0179-3714 | Air Cleaner Instl | Air filter |
| 100-001 | Air Filter | Air filter |
| 100-004 | Air Filter | Air filter |
| 100-005 | Air Filter Element | Air filter |
| 125561 | Air Filter - Primary | Air filter |
| 125562 | Air Filter - Secondary | Air filter |
| PI144D1 | Alternator Model | Alternator |
| UC274C | Alternator Model | Alternator |
| UC274K | Alternator Model | Alternator |
| 100-007 | Battery | Battery |
| 125552 | Belt | Belt |
| 100-008 | Bolt (M12-1.75) | Bolt m12 1 75 |
| 100-003 | Fuel filter | Fuel filter |
| 125551 | Fuel Filter | Fuel filter |
| 100-002 | Oil filter | Oil filter |
| 125550 | Oil Filter | Oil filter |
| 0100-3853-01 | Engine-Diesel (4ISBeG1) | Service part / kit |
| 0179-3628 | Radiator Assy | Service part / kit |
| 0179-4344 | Outlet Sockets Box Instl | Service part / kit |
| 0179-4365 | Fuel System Instl | Service part / kit |
| 0179-4466 | Circuit Breaker Assy | Service part / kit |
| 0179-4472 | Heater Instl | Service part / kit |
| 0179-4517 | Skid Assy (XRS) | Service part / kit |
| 0179-4542 | Battery Isolator Assy | Service part / kit |
| 0300-6029 | Accessory Instl | Service part / kit |
| 0338-0000 | Harnesses | Service part / kit |
| 0403-5265-02 | Spacer-Generator (UC274C) | Service part / kit |
| 0403-5835-02 | Skid | Service part / kit |
| 0403-5850-02 | Skid | Service part / kit |
| 0403-5962 | End Cap-Skid | Service part / kit |
| 0403-5966 | End Cap-Skid (Assy) | Service part / kit |
| 0405-8842 | Enclosure | Service part / kit |
| 101-4000 | Gasket | Service part / kit |
| 127-0826 | Battery | Service part / kit |
| 134277 | T70, T90 & T120 Super Quiet Generator Maintenance Schedule | Service part / kit |
| 153-5720 | Battery | Service part / kit |
| 250-0486 | Oil Filter | Service part / kit |
| 250-0488 | Spark Plug | Service part / kit |
| 8C-3600 | Battery | Service part / kit |
| 8C-3601 | Battery | Service part / kit |
| 8C-3620 | Belt | Service part / kit |
| 8C-3627 | Fuel Filter | Service part / kit |
| V2403-M-E3BG | Engine Model | Service part / kit |
| 100-006 | Spark Plug | Spark plug |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
The Cummins/Onan QSB5-G5NR3 has a displacement of 4.5 liters.
The Cummins/Onan QSB5-G5NR3 powers 1 generator set(s), including Terex T120.
A commonly reported issue on generators using the Cummins/Onan QSB5-G5NR3 is: Fluctuating generator output voltage. Cause: An “ON/OFF” type load may be the cause. Fix: Redistribute load if possible.