The Caterpillar C27 ATAAC is a 27.03 L 12-cylinder ta engine. It powers generator sets from Caterpillar, including the LEHX0009-03 and XQ800.
Service parts for the C27 ATAAC
The cheapest captured merchant offer per filter — see the full cross-reference below for every OEM/aftermarket option.
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Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Oil filter | Duplex primary with integral water separator and change-over valve, engine mounted secondary filter | | 2P4005 | | Amazon eBay $32.99 PartsGeek $23.97 NAPA $33.79 KuduParts $39.00 FridayParts $41.73 |
| Battery | 24 VDC/20A battery charger with float/equalize modes and charging ammeter, Two oversized maintenance free batteries, Solar power battery maintainer | | — | | |
| Oil | Lubricating oil system including pump, integral oil cooler, lube oil, filter, filtered crankcase breather system and oil drain line with internal valve routed to connection point accessible from exterior | 99.0 L | — | 500 hr | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Parts cataloged across the Caterpillar C27 family
37| Part # | Description | Category |
|---|
| 101564109 | Air Shutoff | Air filter |
| 1U-5490 | Hydrosolv 4165 liquid cleaner, 19 L (5 US gallon) | Fluid |
| 2S-3230 | Bearing Lubricant (grease) | Fluid |
| 5N-5561 | Silicone Lubricant | Fluid |
| 01908191 | Overspeed | Service part / kit |
| 101147116 | Engine Operation with Active Diagnostic Codes | Service part / kit |
| 101154196 | Engine Operation with Intermittent Diagnostic Codes | Service part / kit |
| 101233590 | Before Starting Engine | Service part / kit |
| 101446865 | Diagnostic Lamp | Service part / kit |
| 101646248 | After Starting Engine | Service part / kit |
| 102308903 | Starting with Jump Start Cables | Service part / kit |
| 102327037 | Starting the Engine (EMCP II and EMCP II+ (If Equipped)) | Service part / kit |
| 102512380 | Fault Logging | Service part / kit |
| 108-1760 | Ball Bearing (frame 321 BC) | Service part / kit |
| 108-1761 | Ball Bearing (frame 322 BC) | Service part / kit |
| 139-0349 | Bearing (Roller Bearing) | Service part / kit |
| 139-0350 | Bearing (Roller Bearing) | Service part / kit |
| 154-3032 | Ball Bearing (frame 326 BC) | Service part / kit |
| 174-6854 | Hydrosolv 100 liquid cleaner, 19 L (5 US gallon) | Service part / kit |
| 241-4644 | Bearing (frame 320 BC / LC7) | Service part / kit |
| 243-5220 | Bearing (frame 315 BB) | Service part / kit |
| 253-9789 | Bearing (frame 1400 FR) | Service part / kit |
| 261-3545 | Bearing (frame 307 BB) | Service part / kit |
| 262-5921 | Bearing (frame 307 BC) | Service part / kit |
| 263-0161 | Bearing (frame 309 BC) | Service part / kit |
| 301108737 | Cold Weather Starting | Service part / kit |
| 311-0843 | Ball Bearing (frame 1800 FR) | Service part / kit |
| 311-0844 | Ball Bearing (frame 1600 FR) | Service part / kit |
| 5N-4478 | Coupling plate assembly | Service part / kit |
| 5N-4479 | Shim 0.8 mm for coupling plate | Service part / kit |
| 5N-4685 | Varnished cambric tape 15000V | Service part / kit |
| 5N-4686 | Vinyl plastic electrical tape | Service part / kit |
| 5P-2448 | Ball Bearing (frames 580/590) | Service part / kit |
| 6Y-3955 | Ball Bearing (frame 450) | Service part / kit |
| 6Y-6488 | Ball Bearing (frame 597) | Service part / kit |
| 9S-3263 | Thread lock | Service part / kit |
| CR1-CR6 | Diodes in bridge rectifier circuit | Service part / kit |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
Common questions
What is the displacement of the Caterpillar C27 ATAAC?
The Caterpillar C27 ATAAC has a displacement of 27.03 liters with 12 cylinders.
Which generators use the Caterpillar C27 ATAAC engine?
The Caterpillar C27 ATAAC powers 2 generator set(s), including Caterpillar LEHX0009-03, Caterpillar XQ800.
What oil filter does the Caterpillar C27 ATAAC use?
The Caterpillar C27 ATAAC uses oil filter part numbers Caterpillar 2P4005, Donaldson P554005, Wix 51792.
How often should you change the oil in the Caterpillar C27 ATAAC?
The Caterpillar C27 ATAAC oil change interval is every 500 hours.