Genuine Mazda Differential Side Oil Seal / Driveshaft Seal • MA02-27-238A

Genuine Mazda MA02-27-238A Differential Side Oil Seal / Driveshaft Seal

Replacement Genuine Mazda differential side oil seal for Mazda MX-5 Mk1 NA 1.8 models and Mk2/Mk2.5 NB models with 1.6, 1.8 or 1.8 turbo petrol engines.

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 lip wear can cause the original seal to harden or leak. Damage may also occur when a 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 fits the MX-5 Mk1 NA 1.8 differential and the Mk2/Mk2.5 NB differential range. It does not fit the earlier Mk1 NA 1.6 differential, which uses a different side oil 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: Seals differential oil around the rotating driveshaft or output shaft
• 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 clip or hardware included: No
• Brand: Genuine Mazda
• Part No.: MA02-27-238A
• Earlier Mazda reference: MA02-27-238
• MX-5 fitment: Mk1 NA 1.8 and all Mk2/Mk2.5 NB 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
• Oil contamination around the driveshaft flange
• Visible damage to the seal lip after driveshaft removal
• Differential whine or bearing noise caused by low oil level

Fitment advice: This seal is suitable for the original rear differential fitted to MX-5 NA 1.8 and NB/NB-FL models. Confirm compatibility where the differential has been replaced, converted or fitted with an alternative casing or driveshaft arrangement.

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

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

Difficulty guide: DIY Difficulty: Advanced. The rear 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 on the rotating shaft.

What’s in the box: One Genuine Mazda differential side oil seal / driveshaft seal, part number MA02-27-238A.

Installation notes: Raise and support the vehicle safely, then drain the differential oil if required by the applicable procedure. Disconnect and remove the driveshaft carefully without levering against or 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 new 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 the seal for leakage after a road test.