Timken 3907 Automatic Transmission Extension Housing Seal

Timken 3907 Transmission Seal

Timken 3907 is an automatic transmission extension housing seal built to retain lubricant and block contaminants at the transmission tail housing. It is a direct-fit service part for select Buick Riviera and Cadillac Eldorado and Seville applications from the late 1970s through the mid-1980s.

• Precision sealing design helps control fluid escape and keep debris out
• Reinforced outer case resists installation damage and adds durability
• Ribbed rubber inner diameter seals minor spindle imperfections and supports positive seating
• Internal contamination exclusion system helps reduce debris penetration that can lead to leakage
• Vent holes promote lubricant flow around the seal lip to reduce heat build-up

Detailed Product Overview

Built for transmission sealing service, Timken part number 3907 is engineered for the extension housing area where consistent sealing is critical. Its construction combines a reinforced outer case with a ribbed rubber inner diameter to help maintain a secure seal on the shaft surface while accommodating minor surface imperfections. This design supports reliable fluid retention and cleaner operation in the transmission housing.

Compatible With 1979-1985 Buick Riviera, N/A; 1979 and 1982-1985 Cadillac Eldorado, N/A; and 1982-1985 Cadillac Seville, N/A. This part cross-references SKF 11690 for the same application.

Common Repair Uses

• Transmission fluid leaking from the extension housing area
• Contamination entering the rear transmission seal area
• Seal wear caused by heat and lubricant breakdown
• Improper sealing on a shaft with minor surface imperfections
• Service replacement during transmission maintenance on Buick Riviera, Cadillac Eldorado, or Cadillac Seville

Installation Notes

Inspect the housing bore and shaft surface before installation, and clean away old seal material, debris, and fluid residue. Press the seal in evenly to avoid case distortion, and verify the lip seats squarely on the shaft. Confirm application by year and model before ordering Timken 3907.

Quality Assurance

Timken oil and grease seals use precision sealing geometry, contamination exclusion features, and heat-management venting to support dependable transmission service.