The driveshaft seal, also known as the transmission output shaft seal, prevents transmission or differential fluid from leaking where the driveshaft connects. Over time, the seal can wear, crack, or harden, leading to leaks that reduce fluid levels and risk damage to your transmission or differential. Replacing a faulty driveshaft seal ensures proper lubrication and protects vital drivetrain components.

What is a driveshaft seal replacement?

This service involves removing the driveshaft from the transmission or differential, replacing the worn seal with a new one, and reinstalling the driveshaft. The area is then checked for leaks and refilled with fluid if necessary.

Why do you need a driveshaft seal replacement?

If the seal is leaking, fluid loss can cause overheating, increased friction, and eventual failure of the transmission or differential. Replacing the seal promptly helps avoid costly repairs and keeps the drivetrain running smoothly.

Common signs you need a driveshaft seal replacement

• Transmission or differential fluid leaking under the vehicle
• Visible fluid around the driveshaft connection point
• Low transmission or differential fluid levels
• Whining or grinding noises from the drivetrain
• Burning smell from leaking fluid on exhaust components

What happens during a driveshaft seal replacement?

A mechanic will:

1. Inspect the seal and confirm the source of the leak
2. Remove the driveshaft from the transmission or differential
3. Extract the old, worn seal
4. Install a new high-quality seal
5. Reinstall the driveshaft and torque fasteners to specification
6. Refill and check fluid levels
7. Test drive to confirm the leak has been resolved

How much does a driveshaft seal replacement cost?

Replacing a driveshaft seal typically costs $250–$500, depending on vehicle type and drivetrain layout. If the transmission or differential fluid also needs a flush or top-up, costs may increase slightly.

Is it unsafe to drive with a leaking driveshaft seal?

Yes. Driving with a leaking seal risks running the transmission or differential low on fluid, which can cause overheating and major component failure. It’s best to have the seal replaced as soon as a leak is detected.