3S3977 O-Ring for Caterpillar Equipment

The 3S3977 is a standard O-ring used as an axial or radial seal in Caterpillar equipment. It is intended to help prevent leakage and contamination in applicable liquid engine systems with steam cooling. This is a new aftermarket spare part manufactured by CTP (Costex Tractor Parts).

The part is listed for Caterpillar engines and machines, including track-type skidders and wheel-type skidders. The O-ring is identified by the SKU 3S3977 and the part-number format 3S-3977.

Fitment

The following Caterpillar equipment types and models are listed for this O-ring:

• Caterpillar engine-machine applications
• Caterpillar track-type skidders
• Caterpillar wheel-type skidders
• Caterpillar 3204
• Caterpillar 3304
• Caterpillar 4P
• Caterpillar D4HTSK II
• Caterpillar D4HTSK III
• Caterpillar D5HTSK II
• Caterpillar 54H
• Caterpillar 518C

Fitment should be checked against the equipment model and the dimensions of the seal location before installation, because the listed application groups include both engine and skidder equipment.

Cross-reference numbers

• 3S3977
• 3S-3977

Both number formats identify the same listed O-ring reference. The number with the hyphen is the part-number format shown in the technical data, while 3S3977 is the catalog SKU.

Specifications

The dimensional data identifies the O-ring by its cross-section, inner diameter, and outside diameter. The listed EPDM material, black color, 70 Shore A hardness, and operating temperature range describe the supplied seal specification.