O&K L45, 4500Z Parts Catalog – 302 Pages OEM Parts Manual

Description

If you’ve ever ordered a part for an O&K loader and ended up with the wrong bracket or a seal that didn’t fit, you know the waste of time and money. This is the factory Parts Catalog for the L45 and 4500Z, straight from O&K. Not a reprint or a third-party compilation. 302 pages of numbered illustrations and part lists that match the original build.

Group Numbering – How O&K Organizes the Book

O&K uses a three‑part group number to tell you exactly where a part lives on the machine. The first two digits identify the system—Hydraulic System is group 32. The next two pinpoint the assembly—Hydraulic Tank is 05. The last two indicate the specific component—Hydraulic Filter is 01. So group 32‑05‑01 means Hydraulic System, Tank, Filter. That indexing runs through all 302 pages. You find the right page in the front index, then look up the item number on that page’s illustration. No flipping through unrelated sections.

302 Pages – What You Get in This Parts Catalog

Every page in this manual pairs a clear line drawing with a numbered parts table. The table lists the part number, description, and quantity required per assembly. If you need a hydraulic pump seal for a 4500Z, you find group 32, then the pump sub‑group, then item number on the drawing. Write down the part number and order it. That’s it. The manual also includes the original O&K introduction with instructions on how to read the group numbers and order parts. It even reminds you to include the machine serial number with every order—because O&K constantly upgraded these loaders and a serial number mismatch can hand you the wrong part.

Why the Serial Number Matters

The serial number plate is located on the side of the servo console, and the number is also stamped on the left‑hand side of the rear frame below the safety link. Without that number, you cannot guarantee you’ll get the correct part. This catalog was printed in November 1990 (manual TB126, part number 4610459). If your L45 was built after that date, certain parts may have superseded in production. The group numbering system still works, but the exact part number could be different. That’s why O&K requires the machine model, serial number, desired part number, part name, quantity, and shipping address with every order. Skip the serial number and you’re gambling with your downtime.

Ordering Parts the Right Way

Use only parts authorized by O&K. The manual states it clearly: “Use only parts which are authorized by O&K Trojan Inc.” Aftermarket parts that look the same often have different tolerances or material specs. When you order from this catalog, you get the factory part number that matches the original build. The group numbering system also helps if you’re cross‑referencing with a used parts supplier—you can tell them exactly which hydraulic system variant you have. For background on loader design evolution, see the Automotive Industry Overview. That context helps understand why O&K used specific group numbers for their loader series.

Aftermarket vs Factory OEM Parts Documentation

Aftermarket parts catalogs often mess up the group numbers or omit supersession notes. This is the real OEM file—scanned from the original O&K print. If you try to order a hydraulic filter from a generic catalog, you might get a filter that fits a different manifold or has a different thread pitch. The factory parts catalog eliminates that risk. Pair it with the service manual for the L45 or 4500Z for complete coverage. For related factory parts catalogs, check the O&K L45, 4500Z 1990 Parts Catalog – Parts Manual TB126 (that’s this manual), the O&K L3000 Parts Catalog – Factory OEM Manual (236 Pages), and the O&K L2500 Parts Catalog – Factory Specs for Part Ordering. Also see the Automotive Industry Overview for industry standards that shaped O&K’s approach.

Does This Manual Cover Both the L45 and 4500Z?

Yes. The title page says “L45/4500Z” and the manual is designated TB126. It contains both models in one catalog. The illustrations are shared where assemblies are identical, and separate call‑outs appear when parts differ. You order based on your machine’s serial number.

That’s what this manual is for. If you want to stop wasting time on wrong parts, you need the factory piece list. Access the Factory Manual now.

Does this manual cover the L45 and 4500Z models?

Yes, both models are included in one catalog.

What is the difference between a parts catalog and a service manual?

A parts catalog lists every component with part numbers, quantities, and illustrations for ordering. A service manual gives repair procedures, torque specs, and troubleshooting steps. If you need to fix a broken machine, get both. The parts catalog tells you what to order; the service manual tells you how to install it. For example, if you need a hydraulic pump seal, the parts catalog gives the part number (say 123456), but the service manual gives the removal and installation steps. This manual is for identifying and ordering parts only. It will not tell you how to rebuild the pump. Pair it with the corresponding service manual for complete coverage.

Can I use this manual for other O&K models like the L3000?

This catalog is specific to the L45 and 4500Z. For other models, see O&K L3000 Parts Catalog – Factory OEM Manual (236 Pages) or O&K L2500 Parts Catalog – Factory Specs for Part Ordering.

Are the part numbers still valid for current production?

This manual was printed in 1990. O&K may have superseded some parts. Always verify with the serial number and current O&K dealer. The group numbering system, however, remains the standard for identifying systems.