Timken 340847 Automatic Transmission Shift Shaft Seal

Automatic Transmission Shift Shaft Seal for GM Applications

Timken 340847 is an automatic transmission shift shaft seal built with S-Nitrile for dependable sealing at the shaft interface. It is sized for a 0.500 shaft diameter, 0.750 housing bore, and 0.125 width, making it a precise replacement for select Chevrolet, Buick, and Pontiac applications.

Use this seal when servicing a transmission shift shaft leak on vehicles such as the Chevrolet Nova, Corvette, and Monte Carlo. Timken 340847 is also cross-referenced to National 340847 for the same application.

Key Features

• S-Nitrile construction for transmission sealing service
• 0.500 shaft diameter, 0.750 housing bore, and 0.125 width
• Reinforced outer case helps resist installation damage
• Ribbed rubber inner diameter helps seal minor shaft imperfections and improve seating
• Internal contamination exclusion system helps block debris that can lead to leakage
• Vent holes promote lubricant flow around the seal lip to reduce heat build-up

Detailed Description

This Timken automatic transmission shift shaft seal is engineered to retain lubricant at the shift shaft while helping keep contaminants out of the transmission. The precision sealing design, reinforced outer case, and ribbed inner diameter work together to support a secure fit on the shaft and housing. For drivers and technicians servicing classic GM vehicles, Timken 340847 provides a direct-fit sealing solution for select Buick Skyhawk, Chevrolet Monza, Pontiac Sunbird, Chevrolet Nova, Chevrolet Corvette, and Chevrolet Monte Carlo applications.

Timken 340847 is a practical choice for transmission repair work where a worn or hardened shift shaft seal is causing fluid loss. The seal’s vent holes help circulate lubricant around the lip, which supports cooler operation at the sealing surface during service.

What It Helps Fix

• Transmission fluid leaking at the shift shaft
• Contamination entering the transmission through a worn seal
• Seal damage caused by age, heat, or shaft wear
• Poor sealing from minor shaft surface imperfections
• Heat-related seal deterioration around the lip area

Installation Notes and Tips

Inspect the shift shaft and housing bore before installation. Clean the sealing surfaces, verify the 0.500 shaft diameter and 0.750 housing bore match the application, and install the seal squarely to avoid distortion. Confirm vehicle fitment by year and model before service, especially on Chevrolet Nova, Corvette, and Monte Carlo applications.

Quality Assurance

Timken oil and grease seals use precision sealing designs and reinforced construction to support reliable service life in transmission applications. The brand’s sealing design includes contamination exclusion features and heat-management details intended for demanding drivetrain use.