Genuine Mazda Differential Side Oil Seal / Driveshaft Seal • T020-27-238

Genuine Mazda T020-27-238 Differential Side Oil Seal / Driveshaft Seal

Replacement Genuine Mazda differential side oil seal for Mazda MX-5 Mk1 NA models with the 1.6-litre B6 petrol engine.

The seal is pressed into the side of the rear differential housing where the driveshaft or output shaft passes through the casing. Its flexible sealing lip retains the differential oil while allowing the driveshaft to rotate.

Age, heat cycles, driveshaft movement and long-term wear can cause the original seal to harden or leak. Damage may also occur when the driveshaft is removed or installed without protecting the sealing lip.

The same seal fits either the left- or right-hand differential output. Two seals are fitted per vehicle, and this listing supplies one Genuine Mazda seal. Select a quantity of two when replacing both sides.

Fitment restriction: This seal is for the MX-5 Mk1 NA 1.6 differential. It does not fit Mk1 NA 1.8 or Mk2/Mk2.5 vehicles, which use a different differential side seal.

• Part type: Differential side oil seal
• Common names: Driveshaft seal / output-shaft seal / axle seal
• Mazda catalogue description: Seal, Oil
• Location: Side of the rear differential housing
• Function: Retains differential oil around the rotating driveshaft
• Position: Left- or right-hand rear
• Handed component: No
• Supplied pre-greased: Yes
• Quantity fitted per vehicle: 2
• Quantity supplied: 1 seal
• Driveshaft included: No
• Differential oil included: No
• Retaining hardware included: No
• Brand: Genuine Mazda
• Part No.: T020-27-238
• MX-5 fitment: Mk1 NA 1.6 models

Possible signs of a failing differential side seal:

• Gear oil around the differential output or driveshaft joint
• Oil staining on the differential casing or rear subframe
• Differential oil collecting beneath the vehicle
• Falling differential oil level
• Visible damage to the seal lip after driveshaft removal
• Differential noise caused by operation with insufficient oil

Fitment advice: This seal is suitable for the original rear differential fitted to Mazda MX-5 Mk1 NA 1.6 models. Confirm compatibility where the differential, casing or driveshaft arrangement has been replaced or converted.

Other items to consider: Inspect the seal on the opposite side, driveshaft sealing surfaces, output bearings, differential breather, retaining clips and differential oil. A worn, corroded or grooved driveshaft surface may prevent a new seal from operating correctly.

Useful tools / consumables: Axle stands or vehicle lift, socket and spanner set, suitable driveshaft-removal tool, seal puller, correctly sized seal driver, calibrated torque wrench, drain container and the correct specification of differential oil.

Difficulty guide: DIY Difficulty: Advanced. The driveshaft must be disconnected and removed from the differential. The old seal must be extracted without scratching the housing, and the replacement must be installed squarely to the correct depth.

Why Genuine Mazda? Genuine Mazda differential seals are manufactured to match the original housing bore, driveshaft sealing diameter, lip profile and material specification. Correct dimensions help retain differential oil while minimising friction and wear.

What’s in the box: One Genuine Mazda differential side oil seal / driveshaft seal, part number T020-27-238.

Installation notes: Raise and support the vehicle safely, then drain the differential oil where required by the applicable procedure. Disconnect and remove the driveshaft carefully without damaging the differential casing. Extract the old seal using suitable tooling and clean the housing bore. Inspect the driveshaft sealing surface for scoring, corrosion or wear. Protect the replacement seal lip during installation and drive the seal in squarely to the original depth using a correctly sized installer. Refit the driveshaft, renew any retaining clip where required and refill the differential with the correct oil. Check carefully for leakage after a road test.