Honda Civic IV – Drivetrain (1988–1991)

The drivetrain in the Honda Civic IV (1988–1991) has to cope with everyday driving, spirited street use and, in many cases, light tuning. In this category you will find key components that keep the drive system tight and reliable: gearbox shaft and driveshaft seals, selector shaft seals and high-quality gearbox bearings, as well as a performance ACT flywheel for D-series and B16A1 setups.

Seals for gearbox and driveshafts – Honda OEM & NOK

Oil leaks from the manual transmission are a common problem in older Civics. Hardened or cracked seals on the driveshafts or input/output shafts can lead to gradual loss of oil and, in time, damage to the gearbox. In this category you’ll find:

• Driveshaft oil seals – for left and right side, matched to Civic IV gearboxes.
• Selector shaft seals – preventing leaks around the gear-selector linkage.
• Honda OEM seals – factory specification, perfect fit and material quality.
• NOK seals – Japanese manufacturer supplying rotary shaft seals at OEM level, widely used in Honda engines and gearboxes.

Replacing worn seals is essential whenever you see gear-oil mist on the gearbox housing, traces of oil near the driveshaft flanges or when refreshing the drivetrain in a newly purchased car.

Gearbox bearings – Koyo and NTN

Noisy, humming or whining transmissions are a typical sign of worn bearings – especially in high-mileage Civic IV gearboxes. To help with proper rebuilds, the category includes selected gearbox bearings from Koyo and NTN, two renowned Japanese manufacturers used as OEM suppliers in many Honda applications.

• Koyo – Japanese precision bearings, often found in original Honda transmissions.
• NTN – another top-tier Japanese brand, ideal for full gearbox overhauls.

Using quality bearings is crucial if you want a quiet gearbox, precise gear engagement and long-term reliability in D-series and B16A1 powered Civics.

ACT flywheel – for performance-oriented setups

For drivers who expect sharper throttle response and faster engine revs, the category includes a lightweight ACT flywheel. It is designed for tuned D-series and B-series (B16A1) engines and works perfectly with performance clutch kits.

• Quicker engine response and easier rev-matching.
• Better feel in sporty street driving and occasional trackdays.
• Compatible with popular clutch solutions for Civic IV.

A lightweight flywheel is a popular upgrade in classic Civics used for spirited driving, without sacrificing everyday usability when combined with a properly matched clutch.

Why it’s worth refreshing the drivetrain in a 30+ year old Civic

• Prevents oil leaks and gearbox damage caused by low lubricant level.
• Reduces noise, humming and vibration from worn bearings.
• Improves gearshift precision and overall driving comfort.
• Prepares the car for engine upgrades, trackdays or classic-car use.

All parts in this category are carefully selected for compatibility with the Honda Civic IV (1988–1991), including popular D-series engines and the iconic B16A1. You’ll find here components suitable both for OEM-style rebuilds and for enthusiasts who want to upgrade their drivetrain with high-quality Japanese parts.

FAQ – Honda Civic IV Drivetrain

When should I replace gearbox and driveshaft seals?
Whenever you notice oil traces around the driveshafts, selector shaft or on the gearbox housing, or during a clutch/gearbox service. On 30+ year old Civics, proactive replacement is strongly recommended.

What are the symptoms of worn gearbox bearings?
Humming or whining that changes with speed, noise on specific gears, vibration and, in advanced cases, metal particles in the drained oil. Using Koyo or NTN bearings helps restore smooth and quiet operation.

Is a lightweight ACT flywheel suitable for daily driving?
Yes, in most builds it can be used on the street. The engine revs faster and decelerates quicker, which improves response. In very aggressive setups the car may feel more “nervous”, but many Civic IV owners successfully use ACT flywheels in daily use.

Do I need to replace the clutch when installing a new flywheel?
It is highly recommended to inspect the clutch disc, pressure plate and release bearing. In most cases, replacing the clutch kit together with the flywheel is the most efficient and cost-effective solution.

What oil should I use in the manual gearbox of a Honda Civic IV?
The safest choice is genuine Honda MTF-3 (manual transmission fluid) matched to Honda gearboxes. High-quality GL-4 75W-80 oils compatible with Honda MTF can also be used, but OEM MTF-3 remains the reference point.