4M3948 Ring for Caterpillar

The 4M3948 is a transmission seal back-up ring used with Caterpillar equipment. It is a new aftermarket spare part manufactured by CTP (Costex Tractor Parts).

The ring is installed as part of a sealing system. Its stated function is to help prevent seal extrusion in high-pressure applications and to protect the seal assembly when pressure increases suddenly. The component is made from PTFE, also known as polytetrafluoroethylene.

Fitment

The 4M3948 ring is listed for the following Caterpillar equipment models and machine series:

Tracked bulldozers:

• 140
• 141
• 143
• D6C
• D6D
• D6D SR
• D6E
• D6E SR
• D6F SR
• D6G
• D6G SR
• D6G2 LGP
• D6G2 XL
• D7F
• D7G
• D7G2

Pipe layers:

• 571G
• 572G

Track loaders:

• 977K
• 977L
• 983
• 983B

Fitment should be checked against the equipment model, serial number, and the seal assembly in which the ring is installed before ordering or installation.

Cross-reference numbers

• 4M-3948

The product SKU is 4M3948. The formats 4M3948 and 4M-3948 refer to the same listed part number format.

Specifications