Perkins 403C-15 and 404D-22 Engine Parts: A Guide to the Perkins 400 Series Compact Diesel

If you are working on a Perkins 403C-15 or 404D-22 engine, both belong to Perkins' compact 400 Series diesel family — a range of small-displacement engines built for mini excavators, compact utility loaders, small telehandlers, and similar equipment where a full-size diesel would not fit. The 403C-15 and 404D-22 are different engines, but they share the same compact DNA. Arko Tractor Parts, based in Northridge, Los Angeles, carries overhaul kits and engine components for the Perkins 400 Series and ships nationwide. Here is what you need to know before ordering.

Perkins 403C-15 and 404D-22: What Is the Difference?

Both engines come from the Perkins 400 Series — a compact diesel family designed for light equipment applications. The naming convention tells you a lot about each engine:

• 403C-15 — A 3-cylinder engine ("403" = 400 Series, 3 cylinders), with approximately 1.5 liters of displacement (the "15" indicates this). The "C" identifies the emissions generation of this production variant.
• 404D-22 — A 4-cylinder engine ("404" = 400 Series, 4 cylinders), with approximately 2.2 liters of displacement (the "22"). The "D" identifies a later, updated emissions generation compared to the C-series engines.

In practical terms: the 403C-15 is the smaller, older-generation compact engine in the family. The 404D-22 is the larger, newer-generation variant. Both are found across compact construction and utility equipment from multiple manufacturers — because Perkins supplies engines to many different brands, the same engine can appear under a wide range of machine names. The data plate on the engine block is the only reliable way to confirm which variant you have.

For the 403C-15, Arko Tractor Parts carries a full Perkins 403C-15 engine overhaul kit. For the 404D-22, related engine components — including a connecting rod bushing compatible with the 404D-22, 403D-15, and 403D-15T — are available through Arko's full catalog.

Signs You Need an Engine Overhaul or Component Replacement

The Perkins 400 Series engines are compact and work hard. Whether you have the 403C-15 or the 404D-22, watch for these signs of internal wear:

• Blue smoke from the exhaust. Blue smoke means oil is entering the combustion chamber — worn piston rings, cylinder liners, or valve stem seals are the most likely causes. This is a reliable indicator that internal wear has reached the point where an overhaul is warranted.
• White smoke alongside coolant loss or overheating. White smoke on its own has several possible causes. When it appears together with unexplained coolant loss, rising coolant temperatures, or bubbling in the coolant reservoir, a failing head gasket is likely involved.
• Excessive oil consumption. Regularly adding oil between services points to internal burning or leakage — rings, liners, or valve seals.
• Loss of power under load. A compact engine that struggles under normal working loads — once fuel system issues are ruled out — typically has internal wear reducing compression.
• Excessive blowby. Pressure at the oil filler cap or breather tube when the engine is running indicates combustion gas is pushing past worn rings into the crankcase. This is a reliable sign the rings and cylinder bores need attention.
• Knocking from the bottom end. A rhythmic knock that changes with engine RPM points to worn rod or main bearings. On the 400 Series, this can sometimes be isolated to a specific cylinder by shorting out injectors one at a time — the knock will change when the worn cylinder's load is removed.

Aftermarket vs. OEM Overhaul Kits: Honest Pros and Cons

OEM Perkins parts are manufactured to the original factory specification and are the reference standard for fitment and tolerance. For newer D-Series engines still within OEM supply, OEM is available at a premium. For older C-Series variants like the 403C-15, OEM parts can be harder to source and may carry extended lead times.

Aftermarket overhaul kits for the Perkins 400 Series, from reputable suppliers, are manufactured to OEM specifications and tolerances. For working compact equipment — mini excavators, utility loaders, telehandlers — quality aftermarket kits represent strong value and are the practical choice for most operators. The key is sourcing from a supplier that specializes in diesel engine components and can confirm fitment by engine model and serial number. Arko Tractor Parts focuses specifically on diesel engine parts and carries the 403C-15 kit as part of their Perkins catalog.

Tips for Ordering the Right Parts for Your 403C-15 or 404D-22

• Read the engine data plate first. Both the 403C-15 and 404D-22 are supplied to multiple equipment manufacturers. The brand name on the machine does not confirm the engine model. The data plate on the engine block does — it will show the full model designation and serial number.
• Confirm the generation letter. The C in 403C-15 and the D in 404D-22 are not interchangeable designations. C-Series and D-Series components are not the same. Parts for the 403C-15 are not necessarily compatible with the 403D-15, even though they share the same cylinder count and displacement.
• Check the bore size before ordering an overhaul kit. If the engine has been previously rebuilt, the cylinder bores may have been machined oversize. Confirm standard versus oversize before ordering piston and ring components — this applies to both the 403C-15 and 404D-22.
• Have the cylinder head inspected before assembly. On a high-hour compact engine, the cylinder head should be checked for warping and cracks before a new gasket is installed. A compromised head will cause a new gasket to fail regardless of quality.
• Order the full kit if the engine is coming apart. Labor is the expensive part of any engine rebuild. If you are already doing the teardown, replace all major wear components at once — pistons, rings, liners, bearings, and gaskets. The incremental cost of a complete kit is always less than the cost of a second teardown.
• Contact Arko with your serial number if you are unsure. Within the 400 Series, there are production variants where kit specifications changed across serial number ranges. The Arko Tractor Parts team in Northridge works with Perkins engines regularly and can confirm the right parts from your engine data plate details.

Frequently Asked Questions: Perkins 403C-15 and 404D-22 Engine Parts

What equipment uses the Perkins 403C-15?

The 403C-15 is used in a broad range of compact equipment — including mini excavators, compact utility loaders, small telehandlers, and utility vehicles — from manufacturers that source Perkins 400 Series engines. Because Perkins supplies engines to many brands, the machine nameplate alone will not confirm the engine model. The most reliable method is to read the engine data plate directly.

What equipment uses the Perkins 404D-22?

The 404D-22 is the 4-cylinder D-generation variant in the 400 Series and is used in slightly larger compact equipment that needs more displacement than the 3-cylinder 403 variants can provide. Like the 403C-15, it appears in equipment from multiple manufacturers under different brand names. Confirm the model from the engine data plate before ordering any parts.

What is the difference between the C-Series and D-Series in the Perkins 400 family?

The letter following the cylinder number (C, D, etc.) indicates the emissions certification generation of that engine variant. D-Series engines are the updated successors to C-Series engines, certified to later emissions standards. In practical terms, they are different engines — parts are not interchangeable between generations, even when the cylinder count and displacement are the same. Always confirm the full model designation before ordering.

Is a full overhaul kit available for the 404D-22?

A full engine overhaul kit for the 404D-22 is not currently available through Arko's Shopify catalog. However, individual engine components for the 404D-22 — including a connecting rod bushing compatible with the 404D-22, 403D-15, and 403D-15T — are available. Contact the Arko Tractor Parts team directly to discuss what is available for your specific engine and application.

What is included in the Perkins 403C-15 overhaul kit?

The Perkins 403C-15 overhaul kit at Arko Tractor Parts is a full rebuild kit covering the major internal wear components. Confirm the specific kit contents with Arko Tractor Parts before ordering, as contents can vary by production variant and serial number range. Having your engine model and serial number ready will help the team confirm the exact correct kit for your engine.

Can I use 403C-15 parts in a 403D-15?

No — the C-Series and D-Series are different engine generations with different internal specifications. Parts from the 403C-15 are not confirmed compatible with the 403D-15 even though they share the same basic configuration (3-cylinder, ~1.5L). Always match parts to the confirmed engine model and generation. If you have a 403D-15, note that the connecting rod bushing available through Arko is confirmed compatible with the 403D-15 and 403D-15T engines as well.

For Perkins 403C-15 overhaul kits and Perkins 400 Series engine parts, Arko Tractor Parts stocks the 403C-15 full overhaul kit and carries additional 400 Series components. Browse the complete Perkins lineup at shop.arkotractorpart.com/collections/perkins, or contact the team in Northridge, CA directly — they work with Perkins engines regularly and can confirm the right parts for your engine before you order.