Description

Aichi SP21AJ, SP18A, SP21A, SP25B Parts Catalog

You’re ordering parts for an Aichi aerial lift — SP21AJ, SP18A, SP21A, or SP25B — and the aftermarket cross-reference gave you a number that doesn’t fit. The boom cylinder seal kit arrives wrong, the turntable bearing isn’t the right class, and you’re staring at a machine down for another week. That’s what happens when you trust a third-party parts list. This is the real deal: the factory parts catalog straight from Aichi, spanning 673 pages, every illustration indexed, every part assigned a supply class. You need to know exactly which part goes where and whether it’s available as a kit or a single piece. This manual gives you that.

Parts Catalog Coverage: SP18A, SP21A, SP21AJ, SP25B

Four models covered in one bound document. The front cover lists the serial number range: 719370-735816 for the SP18A/SP21A/SP21AJ/SP25B under applied specification EM10-FM0. That means this catalog applies to a specific production run. If your machine falls outside that range, you need to verify. For the ones inside it, every chassis, turntable, weight, tire, and tubing group is broken down. Look for the chapter numbers — 1-CHASSIS, 5-TURNTABLE, 6-TURNTABLE TUBING — and then drill into the sub‑sections. Each illustration page shows the assembly with callouts and a corresponding parts list.

What’s Inside the 673-Page Parts List?

Start with the Foreword in both Japanese and English. It explains the LEVEL column (1 = main assembly, 2 = component, 3 = sub‑component) and the CLASS column (A = replace at disassembly, supplied as repair kit; B = set part only; C = single part; D = not supplied). These codes save you from ordering a part that can’t be bought individually. Then come seven INDEX pages that cover part numbers, followed by 19 ILLUSTRATIONS_INDEX pages that map each illustration to its drawing number. After that, the real meat: CHASSIS group includes the frame, tubing runs, oscillation axle cylinder, steering cylinder, flow divider valve, double pilot check valve, and shuttle valve. Each sub‑section is split into multiple sheets — for example, 1-7 CHASSIS(TUBING) covers 4 sheets, 1-39 STEERING CYLINDER covers 2 sheets. The weight groups (CHASSIS and TURNTABLE) show ballast arrangements. TIRE section (4-1) lists the wheel and tire assemblies. The TURNTABLE section is massive: over a dozen multi‑sheet breakdowns for the upper structure, relay boxes, solenoid valve units, control valves, body assemblies, rotation gearbox, flow priority valve, angle sensors, filters, and the power unit. Turntable tubing (section 6) runs another 8 sheets. Everything from a shuttle valve to a solenoid valve coil is listed with its factory part number and quantity.

19 Illustration Indexes and Grouped Sections

Finding the right drawing is straightforward. The ILLUSTRATIONS_INDEX lists every illustration in the book by group and sheet number. Want the double pilot check valve? Index points you to group 1-47. Need the rotation gearbox? That’s section 5-149. After those indexes, the actual parts breakdowns start. Each page has a clear line drawing with item numbers keyed to the parts table below. The table columns: item number, part number, description, quantity, serial number applicability, and class. No cryptic codes — just what you need to order. For example, under 5-121 SOLENOID VALVE UNIT you’ll see the valve body, coil, and connectors with their individual part numbers and the AR (as required) quantity. This is the same data Aichi’s own parts counter uses.

Use the ‘Class’ Codes to Avoid Wrong Orders

Class A parts are repair kits — you get a complete seal set or gasket package. Class B means you have to buy the whole assembly, not just the loose bolt. Class C is your single part you can order individually. Class D means it’s not serviced separately; you replace the parent assembly. If you order a Class B part as a single item, it won’t ship. This catalog makes that distinction crystal clear. For example, the oscillation axle cylinder (1-37) has Class A seal kit, Class C cylinder body. Check the column before you call the supplier.

Foreword: How to Read This Parts Catalog

The two‑page foreword (English follows Japanese) explains the numbering system. Drawing numbers and group numbers are not consecutive — don’t expect 1,2,3. Instead, each group starts at a multi‑digit number like 1-1, 1-7, etc. The LEVEL column indicates nesting: if you order an assembly, the LEVEL 2 and 3 items are its components. Quantities are for one machine unless otherwise noted. Serial numbers (last four digits) tell you which machines use that part. If your machine is 719400, and the catalog says “719370-735816” for the SP18A, that part fits. This is the precise data you get from Aichi Corporation, not a re‑draw from a third party. AICHI SP18AJ/SP21AJ Operation Manual pairs with this parts catalog for complete service reference. AICHI Parts List SP18A SP18AJ SP21A SP21AJ SP25B is the same set you see here. Aichi SR18AJ SR21AJ SR18A SR21A Parts Catalog – 300pp OEM covers a different series — verify before buying.

Why This Manual Beats Aftermarket Copies

I’ve seen too many techs order a “universal” seal kit that’s close but wrong. Manufacturers change part numbers mid‑production, and aftermarket reprints don’t update. This is an original Aichi PDF — the same file the dealer uses. It’s 673 pages, no watermarks, no blurred numbers. The illustrations are crisp, the tables are formatted for reading on a tablet or printed. You can zoom into a part number without losing clarity. Automotive Industry Overview isn’t relevant here — stick to the factory documentation. Automotive Industry Overview is also not what you need. Trust the source that built the machine.

Does this catalog include part numbers for the SP21AJ oscillation axle cylinder?

Yes. See group 1-37 OSCILLATION AXLE CYLINDER.

How do I know if a part is sold as a kit or individually?

Check the CLASS column. ‘A’ means it’s a repair kit (replace at disassembly). ‘B’ means it’s a set part only (bought as an assembly). ‘C’ means a single part. ‘D’ means not supplied separately. The foreword explains each symbol in detail, and the tables list the class for every line item. This distinction is critical when ordering seals, bearings, and hydraulic components — ordering a Class B part as a single will get your order rejected. Always confirm the class before you call the supplier.

Stop wasting time with parts that don’t fit and suppliers that don’t have the right cross‑reference. This factory parts catalog gives you the exact numbers, the right class codes, and the illustrations you need to identify what you’re holding. Access the Factory Manual and keep it on your shop tablet — you’ll use it every time you rebuild a turntable or replace a steering cylinder.