The Caterpillar CX31 is a 6-speed automatic transmission built for heavy-duty work. It uses a high-capacity torque converter, a hydraulic control system, electronic controls, and heavy-duty gearing, and it is found in construction, mining, and heavy-truck applications paired with Caterpillar diesel engines.
This is a commercial part, not a passenger-car transmission. Fitting it is a commercial driveline job, and the unit is electronically controlled, so it must be matched to the engine ECM and the vehicle controls. Confirm the host machine, the engine, and the exact configuration before you buy.
Because this is a high-value used unit, ask for the serial number, the rebuild and test history, the input and output configuration, and the control-module and software compatibility for your application.
| Item | Details |
|---|---|
| Host machine and engine | Confirm the exact machine or truck and the CAT engine |
| Configuration | Mounting, input and output, and control module by serial |
| History | Rebuild and test history for a high-value used unit |
Confirm the exact host machine or truck and the Caterpillar engine.
Confirm the mounting, input and output configuration, and gear ratios by serial.
Confirm the control module and software compatibility (it is electronically controlled).
Confirm the rebuild and test history for this high-value used unit.
| Item | Details |
|---|---|
| INCLUDED | The Caterpillar CX31 transmission as confirmed by serial. Call to confirm the exact configuration, the control module, and what is included for your application. |
| NOT INCLUDED | Engine, ECM, wiring, cooler, driveline, fluid, and any control module or software are not included unless specifically confirmed in writing. |
| Tools You Need | Commercial driveline installation only. The CX31 is electronically controlled and must be matched to the engine ECM and vehicle controls by a qualified heavy-equipment or heavy-truck technician. |
The live page lists a very broad set of machines, trucks, and engines. That list is too broad to take at face value; the exact fit depends on the serial, the engine, and the control configuration.
| Vehicle | Compatibility |
|---|---|
| Caterpillar machines | Various (per live list); confirm by serial |
| On-highway trucks | Various brands (per live list); confirm by configuration |
| Confirm | Serial, engine, and control module for your application |
The live applications list spans many Caterpillar machines, several on-highway truck brands, and other-brand equipment. Because a single transmission cannot be a universal fit across all of those, treat the list as a starting point only and confirm the exact fit by serial, engine, and control configuration before you order.
Not sure the CX31 matches your machine or truck? Call (240) 301-0095 or email support@vazautosolutions.com with the host machine, the Caterpillar engine, and any serial information. We will help confirm the configuration, the control module, and current availability.
Quality control for this part includes:
Serial number recorded and verified
Rebuild and test history documented where available
Torque converter and control system inspected
Input and output configuration confirmed
Fluid condition and case checked for leaks
Because this is a high-value used commercial transmission, we record and verify the serial, document rebuild and test history where available, and inspect the torque converter and control system. Request the full history before purchase.
| Model | Caterpillar CX31 |
|---|---|
| Type | electronically controlled | 6-speed automatic |
| Torque Rating | 850 lb-ft |
| Gear Ratios | 5.00 | 3.00 | 1.86 | 1.00 | 0.72 | 0.54 |
| Torque Converter Stall | 1 | 800 RPM |
| Maximum Input Output Rpm | 2 | 500 RPM |
| Mounting | SAE 2 flywheel housing |
| Input Output Shaft | 2.50 in diameter | 12 splines |
| Fluid Type | Caterpillar TO-4 |
| Fluid Capacity | About 12 quarts |
| Overall Length | About 47.5 in (29 in bellhousing to tailshaft) |
| Weight | About 770 lbs |
| Sku | vaz237 |
Contact (240) 301-0095 within 15 days of delivery.
