Description

Furukawa Unic URV230, URV260, URV290, URV300, URV340 Workshop Manual

I’ve been turning wrenches for 28 years, ASE Master, and I’ve seen more boom failures from guys skipping the factory spec than from wear. If you’re tearing down a Unic crane and you don’t have the OEM workshop manual in your hand, you’re asking for a hydraulic leak that’ll cost you a week’s pay. This Furukawa Unic URV230, URV260, URV290, URV300, URV340 Workshop Manual — 110 pages, factory printed in Japan — gives you the exact disassembly sequence, telescoping cylinder port maps, and slide plate tolerances. No aftermarket rewrites. No guessing.

Complete Boom Disassembly Procedures for URV230-URV340

That boom section in the TOC breaks down 2-section, 3-section, 4-section, and even 5-section booms. Each subsection gives you the construction, operation, and disassembly steps in the order a technician needs. The 4-section boom section alone covers boom-top sheave mounting, slide plate and guide installation, and front/rear side detail views for every boom pair. Page 14 walks you through the full teardown of a 4-section boom on the URV series. You don’t get that from a third-party summary.

Telescoping Cylinder Hydraulics: Extend and Retract Cycles

Chapter 3 goes into the telescoping cylinder sequences for each boom configuration. Single-cylinder for the 2-section, dual-cylinder for the 3-section and 4-section. Each subsection shows exactly what happens when the cylinder extends and when it retracts — port flow direction, mechanical lock points, and retraction sequencing. If you’re chasing a cylinder that drifts or a boom that won’t stage properly, this is where you find the factory logic. Understanding hydraulic pilot systems is similar to the fluid path logic in a Manual Transmission but the crane uses separate pilot circuits for each stage.

Does This Manual Cover the URV500?

The front cover of this manual lists URV230, URV260, URV290, URV300, and URV340. The introduction page does mention URV370 and URV500 as part of the series, but the TOC content focuses on the five models in the title. The 5-section boom section on page 18 is written for a simultaneous telescoping boom 4 and boom 5 arrangement — that matches the URV500 configuration, but the specific parts references may differ. If you are working on a URV500, get the dedicated manual. This one covers the URV230 through URV340 accurately.

110 Pages of Factory-OEM Documentation

Thumb through the first page and you see the Furukawa Unic Corporation stamp and a printed-in-Japan notation. That is the difference between a real workshop manual and a copy that had the spec sheet retyped. The TOC runs 110 pages of actual factory drawings, assembly sequences, and exploded views. You get the construction of the boom-top sheave mounting (page 9), the slide plate installation procedure (page 10), and the full 4-section boom disassembly steps (page 14). I’ve had too many headaches from aftermarket manuals that skip the ‘how to mount the guide plate’ step. This one doesn’t. It’s the same document the dealer tech uses.

Use the Correct Slide Plate Installation Sequence

Slide plate and guide installation is not a ‘line up and bang it in’ job. The manual gives the exact procedure for URV-series booms, including the order of tightening and the clearance checks. Ignore that and you’ll bind the boom sections under load. If you need the operator’s manual for a related model, check the Furukawa Unic URV370 Operators Manual – 108 Pages, Factory OEM. For parts breakdowns, the Furukawa Unic URV370 Parts Catalog – 481-Page Factory Spec is your companion. And if you are working on the URV290 specifically, the Furukawa Unic URV290 Operators Manual – Factory Crane Specs covers daily operations. But for tear-down and rebuild, this workshop manual is the right tool.

FAQ

Does this manual include torque specifications?

No. This manual covers construction and disassembly procedures, not torque values. You’ll need the service manual supplement for fasteners.

Can I use this for the URV500 model?

The manual listed covers URV230, URV260, URV290, URV300, and URV340. However, the introduction page does list URV370 and URV500 as part of the URV series. The assembly sections may share common components, but the specific disassembly steps for a 5-section boom on the URV500 might differ. I’d recommend getting the dedicated URV500 workshop manual if you’re working on that specific machine. Do not assume interchangeability without cross-referencing part numbers. The Manual Transmission analogy applies: just because the gear layout looks similar doesn’t mean the clutch pack is the same.

If you’re rebuilding a boom or swapping a telescoping cylinder on any URV230, URV260, URV290, URV300, or URV340, you need the factory print. Access the Factory Manual and get the correct disassembly sequence, slide plate tolerances, and cylinder operation logic. No aftermarket shortcuts. No missing pages. 110 pages of OEM documentation ready for your workbench.