Honda Engine Bearings – OEM vs. Aftermarket. Why Taiho Is a Safe Choice for Engine Rebuilds

Honda Engine Bearings – OEM vs. Aftermarket. Why Taiho Is a Safe Choice for Engine Rebuilds

If you're in the process of rebuilding your Honda engine and researching main or rod bearings, you've probably come across the name Taiho – a Japanese manufacturer of precision engine bearings. One of the most common questions mechanics and enthusiasts ask is: Are Taiho bearings installed by Honda from the factory? And if so, how do they differ from the ones available in aftermarket kits? This article breaks down the differences between Honda OEM engine bearings and aftermarket Taiho bearings, and explains why Taiho remains a reliable choice when rebuilding your engine.

Taiho – Trusted OEM Supplier for Honda

Taiho Kogyo Co., Ltd. is a world-renowned Japanese manufacturer of engine bearings and internal engine components. It supplies original bearings for many automakers including Honda, Toyota, Nissan, Mazda, and Suzuki. In Honda's case, Taiho is the OEM supplier of engine bearings installed during factory assembly.

What Are OEM Bearings Used by Honda?

OEM (Original Equipment Manufacturer) bearings are produced under strict tolerances and specifications set by Honda. What makes them unique is the grading and color coding process:

• Every engine block and crankshaft is individually measured during production.

• Based on those measurements, specific bearing sizes are selected and color-coded (e.g., Yellow, Green, Brown, Pink).

• This ensures ultra-precise oil clearance of around 0.002–0.005 mm, optimized for long-term performance.

This selective fitting process is a major reason for the reliability and longevity of Honda engines.

Taiho STD Bearings – Aftermarket Does Not Mean Inferior

Taiho's aftermarket bearings (e.g., Taiho M474A-STD) are designed for engine repair and rebuilding. They differ from OEM in the following ways:

• No grading or color codes – bearings come in standard sizes (STD) or oversizes (0.25 mm, 0.50 mm).

• Wider tolerance range – to allow for flexible installation in various engines.

• Same materials as OEM bearings – tri-metal or bi-metal construction, depending on application.

These bearings are built to high Japanese Industrial Standards and ISO certifications. The absence of grading does not mean lower quality – it just shifts the responsibility of fitting to the mechanic.

What You Need to Know Before Installing Aftermarket Bearings

When using Taiho aftermarket bearings to rebuild a Honda engine, you must:

1. Precisely measure crankshaft journals and bearing bores.

2. Determine proper oil clearance, usually 0.0015–0.0020 inch (0.038–0.051 mm).

3. Use tools like micrometers, bore gauges, or plastigauge for accurate readings.

4. Choose the correct bearing thickness (STD or oversize) based on your measurements.

Why Can't You Buy Graded Bearings?

Honda does not sell color-graded OEM bearings individually. The reasons are:

• Graded bearings are factory-selected based on specific combinations of block and crank measurements.

• Without the exact block and crank codes, it's nearly impossible to match them correctly.

• OEM bearings are sometimes available through dealers but require special orders and high costs.

Comparison Table: Honda OEM vs. Taiho Aftermarket Bearings

Final Verdict: Are Taiho Bearings a Good Choice for Rebuilding Honda Engines?

Yes. If you're rebuilding a Honda engine and want high-quality, reliable engine bearings, Taiho aftermarket bearings are an excellent choice. They offer:

• OEM-level durability

• Compatibility with Honda engine architecture

• Proven performance in thousands of engine rebuilds

As long as you perform accurate measurements and follow best practices during installation, Taiho bearings will perform reliably over the long haul – just like the originals.