A maintenance supervisor at a pipeline contractor in Louisiana pulled a CAT 330F off a levee project after the operator reported a deep, rhythmic shudder at idle. Fuel consumption had crept up 8% over three months. The hydraulic pump coupling showed early spline wear. The root cause: both front engine mounts — Caterpillar Part No. 175-4625 — had collapsed past 30% compression set after 7,800 hours. Two replacement mounts and 90 minutes of labor put the machine back on grade.
The 175-4625 is one of Caterpillar’s most widely used engine mount part numbers, fitted across the 320, 330, and 336 excavator families. This guide covers exact fitment, specifications, failure symptoms, and how to source OEM-compatible replacements.
Part Specifications: CAT 175-4625
| Property | Value |
|---|---|
| OEM Part Number | 175-4625 (Caterpillar) |
| Alternative Reference | 1754625 |
| Component | Engine mount — front/rear positions |
| Rubber Compound | Natural rubber (NR) / HNBR blend |
| Shore A Hardness | 50 ±5 |
| Operating Temperature | -40°C to +120°C (-40°F to +248°F) |
| Static Load Capacity | 2,800 kg per mount |
| Dynamic Load | Up to 5,500 kg |
| Bolt Pattern | M16 x 2.0, 4-bolt square pattern |
| Mount Height (unloaded) | 76mm |
| Weight | 3.8 kg |
Machine Fitment Chart
The 175-4625 engine mount fits the following Caterpillar excavators:
| Model | Engine | Mount Position | Qty per Machine |
|---|---|---|---|
| 320D L | C6.4 ACERT | Front left, Front right | 2 |
| 320E L | C6.4 ACERT | Front left, Front right | 2 |
| 320F L | C4.4 ACERT | Front left, Front right | 2 |
| 323F L | C4.4 ACERT | Front left, Front right | 2 |
| 330D L | C9 ACERT | Front left, Front right | 2 |
| 330F L | C7.1 ACERT | Front left, Front right | 2 |
| 336E L | C9.3 ACERT | All positions | 4 |
| 336F L | C9.3 ACERT | All positions | 4 |
| 336F LN XE | C9.3 ACERT | All positions | 4 |
Note: Rear mounts on 320/330 models use a different part number (6I-6723). Always verify against your machine serial number prefix.
When to Replace: 5 Warning Signs
1. Increased Cab Vibration at Idle
The 175-4625 is tuned to absorb C-series engine firing frequencies (25–35 Hz). When rubber degrades below 45 Shore A, these frequencies pass through to the mainframe and into the cab. If operators report a “buzzing” sensation at low idle (700 RPM), check the front mounts first.
2. Visible Engine Movement
With the engine running at high idle, observe the engine from the pump access door. Movement exceeding 3mm in any direction indicates mount failure. Healthy mounts limit movement to under 1mm.
3. Rising Fuel Consumption
Degraded mounts allow engine misalignment, increasing parasitic load on the hydraulic pump coupling. A 5–10% fuel increase without other explanation often traces back to engine mount wear.
4. Pump Coupling Noise
A clicking or rattling sound from the pump-engine coupling area at variable RPM suggests angular misalignment caused by uneven mount settlement.
5. Rubber Cracking or Oil Contamination
Visual inspection reveals surface cracks deeper than 2mm, permanent deformation, or oil saturation from hydraulic leaks. Any of these requires immediate replacement.
Installation: Step-by-Step
Required tools: 24mm socket, torque wrench (150 Nm capacity), engine support bar or overhead hoist, hydraulic jack with 5-ton capacity.
Time: 60–90 minutes per pair (2 mounts).
- Park machine on level ground. Lower all attachments. Engine OFF, key removed.
- Open the engine compartment. Disconnect battery ground cable.
- Position the engine support bar or attach hoist to engine lifting eyes.
- Raise engine 5–10mm with jack or hoist to unload the mounts.
- Remove the 4x M16 bolts from the mount — 2 on engine bracket, 2 on frame bracket.
- Slide old mount out. Inspect the mounting surfaces for corrosion or damage.
- Install new 175-4625 mount. Ensure the rubber compound faces UP (metal plate faces DOWN to frame bracket on front mounts).
- Hand-thread all 4 bolts before torquing. Final torque: 135 Nm (100 lb-ft).
- Lower engine onto new mounts. Remove support bar/hoist.
- Start engine. Run at low idle for 5 minutes, then high idle for 2 minutes. Check for abnormal vibration.
- Re-torque bolts after 50 operating hours.
Critical: Always replace front mounts as a pair. Replacing only one side creates uneven loading and accelerates failure of the new mount.
OEM vs. Aftermarket: What to Specify
| Criteria | OEM (Caterpillar) | Babacan Group (OEM-Compatible) |
|---|---|---|
| Part Number | 175-4625 | BG-1754625 |
| Material | NR/HNBR | NR/HNBR (same compound class) |
| Hardness | 50 Shore A | 50 ±5 Shore A |
| Dimensions | Per CAT spec | Matched to CAT spec |
| Temperature Range | -40°C to +120°C | -40°C to +120°C |
| Certification | CAT QA | ISO 9001:2015 |
| Lead Time | 2–6 weeks (dealer stock varies) | 5–10 business days |
| Warranty | CAT standard | 12 months |
Babacan Group manufactures the 175-4625 engine mount to the same dimensional and material specifications as the Caterpillar original. Every batch is hardness-tested, compression-set tested, and dimensionally verified before shipping.
Related CAT Engine Mount Part Numbers
If you’re maintaining a mixed CAT fleet, these are the most common engine mount part numbers across the product line:
- 6I-6723 — Rear engine mount for 320D/E/F
- 1U-3352 — Engine mount for 345D/349F
- 2T-3013 — Engine mount for 365C/374F
- 6G-9547 — Cab mount pad for 320/330 series
- 9W-9931 — Engine mount for 390F/395
Browse all CAT rubber parts in our catalog.
Bulk Ordering for Fleet Operations
For contractors running multiple CAT 320/330/336 units, Babacan Group offers:
- Volume pricing starting at 10+ units
- Fleet kits — complete mount sets (front + rear) per machine model
- Consignment stocking for high-usage part numbers
- Technical support — our engineers confirm fitment against your machine serial numbers
Request a fleet quote with your machine model, serial prefix, and quantity.
Frequently Asked Questions
Can I use the 175-4625 on a CAT 325F?
The 325F shares the C7.1 engine platform with the 330F. Confirm your serial prefix with our parts team — some 325F configurations use a different mount bolt pattern.
How many hours between replacements?
Plan for replacement at 5,000–7,000 hours in standard applications. In high-vibration applications (breaking, demolition), reduce the interval to 3,500–5,000 hours.
Do I need to replace all 4 mounts at once on a 336F?
Best practice is to replace all 4. At minimum, replace front and rear pairs together. Never replace a single mount — uneven loading will destroy the new mount within 2,000 hours.
Contact us for part number verification, pricing, or technical questions.