CAT 3T-3725 Thick External Seal Ring (3.12 mm)

Product Overview

The CAT 3T-3725 Thick External Seal Ring is a genuine Caterpillar OEM plastic external seal ring engineered to provide an effective sealing interface within planetary transmission assemblies. Designed to Caterpillar’s exact OEM specifications, this seal ring helps prevent internal fluid leakage, maintain hydraulic pressure, and protect transmission components from contamination, ensuring reliable performance under demanding operating conditions.

Manufactured from a high-performance engineering plastic, the 3T-3725 External Seal Ring offers excellent wear resistance, dimensional stability, and compatibility with transmission operating environments. As a direct OEM replacement, it delivers precise fitment and dependable sealing performance throughout the service life of the transmission.

Key Features

• Genuine Caterpillar OEM Thick External Seal Ring
• Part Number: 3T-3725
• Nominal Thickness: 3.12 mm
• Designed for planetary transmission applications
• High-performance engineering plastic construction
• Provides effective sealing between transmission components
• Helps maintain hydraulic pressure and lubrication
• Reduces internal leakage and contamination
• Resistant to wear and transmission operating conditions
• Direct OEM replacement for Caterpillar planetary transmission systems
• Manufactured to Caterpillar quality standards for long service life

Technical Specifications

Application Information

The CAT 3T-3725 Thick External Seal Ring is designed for installation within Caterpillar planetary transmission assemblies where reliable sealing is essential for maintaining transmission efficiency and durability.

The seal ring helps to:

• Prevent internal hydraulic and lubricant leakage
• Maintain proper transmission oil pressure
• Reduce contamination between transmission components
• Improve planetary transmission efficiency
• Minimize component wear
• Support long-term transmission reliability

Using a genuine Caterpillar seal ring helps preserve OEM sealing performance and contributes to extended service life in demanding construction, mining, quarrying, and off-highway applications.

Compatible Caterpillar Equipment

The CAT 3T-3725 Thick External Seal Ring is compatible with numerous Caterpillar machines, including:

Road Reclaimers

• RM500
• RM-350B
• RM500B

Stabilizer Mixers

• SM-350

Reclaimer Mixers

• RM-350
• RM-350B
• RM-500
• RM500B

Underground Articulated Trucks

• AD40
• AD45
• AD45B
• AD55
• AE40
• AE40 II

Articulated Trucks

• 735
• 735 OEM
• 735B
• 740
• 740B
• D400E II

Wheel Tractors

• 631E
• 637E

Quarry Trucks

• 770G
• 771C
• 771D
• 772G

Off-Highway Trucks

• 770
• 772
• 773GC

Trucks

• 69D
• 769C
• 769D
• 770
• 770G
• 770G OEM
• 772
• 772G
• 772G OEM

Tractors

• 768C

Ejector Trucks

• 740
• 740B
• D400E II

Compatibility should always be verified using the machine Product Identification Number (PIN), serial number, or transmission arrangement number before ordering, as transmission configurations may vary by machine configuration.

Additional Compatibility Information

The 3T-3725 Thick External Seal Ring is a configuration-specific transmission sealing component. Before installation, verify:

• Machine model
• Product Identification Number (PIN)
• Machine serial number
• Transmission arrangement number
• Existing seal ring part number
• Planetary transmission configuration
• Seal dimensions and installation location

Any changes to the original equipment configuration may affect compatibility. Confirmation through Caterpillar parts information or an authorized Cat dealer is recommended.

Benefits

Installing a genuine CAT 3T-3725 Thick External Seal Ring helps:

• Maintain proper planetary transmission sealing
• Reduce internal oil leakage
• Protect transmission components from contamination
• Improve transmission efficiency and reliability
• Extend the service life of planetary transmission assemblies
• Reduce maintenance costs and unplanned downtime
• Ensure OEM fit and sealing performance
• Deliver long-lasting durability in demanding heavy equipment applications