Hyundai / Kia Uprated Synchromesh Repair Kit

Hyundai / Kia Uprated Synchromesh Repair Kit – M6CF3-1 6-Speed Gearbox

This is an uprated synchromesh repair kit for the Hyundai and Kia M6CF3-1 6-speed manual gearbox. It contains replacement synchro rings and oil seals to restore smooth, positive gear selection and prevent oil leaks — all common wear items in a gearbox rebuild. Using uprated components helps extend service life beyond the original specification.

Kit includes:

• x1 Kia Oil Seal – 4313439012
• x1 Kia Oil Seal – 4311939080
• x1 Kia Oil Seal – 4311939070
• x4 Synchro Ring – 4339432410

Fits transmission: M6CF3-1 (6-speed manual)

Vehicle compatibility:

• Hyundai: Accent, i20, i30, i40, ix20, ix35, Kona, Tucson, Veloster
• Kia: cee’d, Cerato, Pro cee’d, Rio, Soul, Sportage, Stonic, Venga, XCeed

What are the symptoms of worn synchromesh rings?

Common signs include crunching or grinding when changing gears (especially into 2nd or 3rd), difficulty engaging gears when cold, or gears jumping out under load. Worn synchro rings are a leading cause of these issues.

Are these uprated rings stronger than standard?

Yes — uprated synchro rings are manufactured with improved friction materials or harder compounds to provide better engagement and longer service life than the original equipment items.

What vehicles does the M6CF3-1 gearbox fit?

The M6CF3-1 is a 6-speed manual unit shared across the Hyundai and Kia range including the i30, Tucson, Sportage, cee’d and Kona families. Please confirm your specific model using your VIN if unsure.

Is professional fitment required?

Yes — synchromesh replacement requires full gearbox disassembly and specialist tools. This kit is intended for professional rebuilders or experienced transmission specialists.

Can I confirm fitment before ordering?

Yes — send us your vehicle registration or VIN and we will confirm this kit is correct for your gearbox before you order.

Why Choose Eco Torque?

As specialists in gearbox rebuilds and repairs, Eco Torque takes pride in offering genuine gearbox parts, high-quality aftermarket alternatives and competitive pricing.

Need Help Finding the Right Part?

If you are unsure whether this part is compatible with your vehicle, send us your UK registration number or VIN and we will help you find the correct part.

Reference Number: ETB2364