6204-21-4230 6204214230 Flywheel Housing for Komatsu 4D95 B3.3

6204-21-4230 Flywheel Housing for Komatsu 4D95 Engine

The 6204-21-4230 / 6204214230 flywheel housing is used for Komatsu 4D95 and B3.3 engine rear housing applications. It is also searched as a flywheel housing, bell housing, rear engine housing or housing flywheel for Komatsu compact excavator, wheel loader and equipment engine repair.

This page focuses on 6204-21-4230 as the main part number. Before ordering, the removed housing should be checked by old housing number, engine serial number, starter opening, SAE housing size, mounting face, bolt pattern, rear seal area and inside outside housing photos.

Komatsu 4D95 Flywheel Housing Application

The main engine reference for this part is Komatsu 4D95. Public aftermarket listings also commonly mention B3.3 engine references and machines such as Komatsu PC88MR, PW98MR, WA65, WA70 and WA90. These model names should be treated as checking references only.

Flywheel housing configuration can vary by engine serial number, equipment type, starter position, SAE size and transmission connection. Do not select the housing by machine model alone if the old housing number or photos are not available.

Part Number and Catalog Reference Notes

The main part number for this page is 6204-21-4230. The no-hyphen format 6204214230 is also used in supplier catalogs and buyer searches.

Catalog sources describe 6204-21-4230 as HOUSING, FLYWHEEL for Komatsu. Some aftermarket pages may list nearby flywheel housing numbers such as 6204-21-4160 or 6204-21-4190 together with 6204-21-4230. These should be used only as catalog checking references unless the old housing confirms the same configuration.

To keep this product page focused, 6204-21-4230 should remain the primary search signal. Related references should not replace physical confirmation of the old housing, starter opening, mounting face and bolt pattern.

Flywheel Housing Function

The flywheel housing is installed at the rear side of the engine. It surrounds the flywheel area and provides the mounting interface for the starter, rear engine connection and equipment-side drive system.

Correct housing selection is important because the starter opening, bolt holes, rear seal area, pilot diameter and mounting face must match the original engine and machine configuration. A similar-looking housing may still fail to fit if these details are different.

How to Identify the Correct 6204-21-4230 Housing

• Check whether the old housing number matches 6204-21-4230 or 6204214230.

• Confirm the engine model, especially Komatsu 4D95 or B3.3 references.

• Compare starter opening position and starter mounting holes.

• Check the rear mounting face, bolt pattern and pilot diameter.

• Inspect the rear seal area and flywheel clearance position.

• Send inside and outside housing photos when the casting number is unclear.

Common Damage and Replacement Signs

• Cracks around the starter opening, mounting face or rear support area.

• Broken bolt holes caused by vibration, impact damage or over-tightening.

• Starter alignment problems caused by worn or damaged housing surfaces.

• Oil leakage near the rear seal area caused by damaged sealing surface.

• Abnormal vibration caused by rear mounting misalignment or damaged housing structure.

Troubleshooting Before Replacement

Before replacing the 6204-21-4230 flywheel housing, inspect the rear engine mounting area. Housing damage may be caused by loose mounting bolts, engine mount failure, starter installation problems, driveline misalignment or previous impact damage.

• Check engine mount and rear support condition.

• Inspect starter motor mounting area and ring gear engagement condition.

• Check mounting surface flatness, bolt threads and dowel locations.

• Inspect the flywheel, rear seal and connected drive-side components.

• Confirm whether the housing failure was caused by the housing itself or by external stress and misalignment.

Installation and Maintenance Notes

• Clean the engine rear face and housing mounting surface before installation.

• Compare the old and new housing before assembly, especially starter position and bolt pattern.

• Check dowel pins, bolt holes and mounting face alignment before tightening.

• Replace rear seal or sealing parts if required during housing installation.

• Use the correct tightening sequence and avoid uneven mounting stress.

• After installation, check starter engagement, oil leakage, vibration and mounting bolt security.

Fitment Check Before Ordering

To reduce wrong orders, please send the old housing number, engine model, engine serial number, machine model, outside photo, inside photo, starter opening photo, mounting face photo, bolt pattern photo and any visible casting marks before quotation.

FAQ

Q: What is 6204-21-4230?

6204-21-4230 is a Komatsu flywheel housing reference used for engine rear housing applications.

Q: Is 6204214230 the same number format?

Yes. 6204214230 is the no-hyphen search format of 6204-21-4230. Both formats can be used for catalog checking.

Q: Which engines are common references?

Komatsu 4D95 and B3.3 are common engine references in public product listings. Final fitment should be checked by old housing number and engine serial number.

Q: Which machine models are common references?

Common checking references include Komatsu PC88MR, PW98MR, WA65, WA70 and WA90. These model names should not replace physical housing verification.

Q: What should be checked before ordering?

Check the old housing number, engine serial number, starter opening, SAE housing size, mounting face, bolt pattern, rear seal area and inside outside photos.