Description

Furukawa Unic UR330, UR500, UR220, UR250, UR260 1989 Workshop Manual

If you have ever tried to rebuild a telescoping cylinder on a UR series crane using a third-party translation, you know exactly why I am writing this. That garbage wastes your time and risks your safety. This is the factory manual from Furukawa Unic, printed in 1989, 119 pages of actual procedures, not guesswork. I have been turning wrenches for almost three decades, and I will tell you flat: if you want to keep a UR220 or UR500 out of the boneyard, you need the specs that the guys in Tokyo signed off on. Not a generic hydraulics guide.

119 Pages of Factory Documentation

Every page in this manual comes from Furukawa Unic Corporation’s service department, dated June 1989. The table of contents lists six major sections: General View, Boom, Telescoping Cylinder, Base, Outrigger Cylinder, and Slewing Device. Page 2 starts with a general view and the introduction. If you are in a hurry, page 63 gives you the tightening order and torque values for the turntable bolts. That is the kind of detail you do not get from a reprinted copy that lost half the numbers to bad scanning.

Boom Disassembly: 3-Section, 4-Section, and 6-Section

Section 2 of the manual covers the boom in seventeen pages. It walks through disassembly for three different boom configurations. The 3-section boom procedure starts on page 4, the 4-section boom on page 6, and the 6-section boom on page 9. Each procedure includes step sequences, not just pictures. You also get instructions on housing the boom telescoping cylinder for multi-section booms, plus the simultaneous extension/retraction mechanism for sections 4, 5, and 6. If you skip the wire rope adjustment section on page 19 for the 4-section boom, you will regret it when the crane refuses to retract evenly.

Telescoping Cylinder Rebuild: Why Factory Specs Matter

Section 3 dives into the telescoping cylinder from page 24. It covers construction for 2-section through 6-section booms. There is a separate subsection for the dual telescoping cylinder disassembly on the 3-section boom (page 28) and an explanation of dual cylinder operation on page 35. The manual also breaks down the cushion seal function on page 40. That cushion seal is not a gimmick – it prevents shock loads when the cylinder bottoms out. Aftermarket manuals sometimes describe the seal cross-section wrong. This one shows the actual Furukawa Unic design.

Does This Manual Cover the UR500 and Other Models?

Yes. The title page lists UR220, UR250, UR260, UR290, UR330, UR360, and UR500. The procedures in the telescoping cylinder section apply across the UR series because the hydraulic architecture is consistent. Section 5 on outrigger cylinders includes high outrigger versions specific to larger models. If you are working on a UR500, you need the wire rope adjustment for the 6-section boom on page 22 and the triple cylinder explanation on page 38. Do not assume a smaller model manual will get you there.

Trust the Factory Torque Values on Page 67

Page 67 lists the tightening torque for bolts fastening the turntable and slewing reduction gear. The manual also gives the numeral tightening order for turntable bolts on the same page. If you use a generic torque value from a maintenance guide, you risk stripping the tapped holes in the slewing ring. Furukawa Unic specifies these values in imperial units – I have seen enough aftermarket manuals that round them off and cause leaks. This manual also covers the soft zone position on the turntable (page 63) and the correct sequence for mounting the turntable. Follow the order, or the ring will bind.

I have seen guys try to rebuild the outrigger cylinder without the pilot check valve construction drawing in section 5. That pilot check valve is what keeps the outrigger from dropping when the hose ruptures. The manual shows exactly where the valve fits and the internal porting. If you are a shop owner, hand this manual to your apprentice and tell him to read the cushion seal explanation before he touches a cylinder. It will save you a comeback.

Related manuals you might need: UNIC UR330 Series Operators Manual for daily operation controls, UNIC UR330 Series Hydraulic Crane Parts Manual for parts ordering, and UNIC HYDRAULIC CRANE 500 SERIES Operators Manual for the larger frame. If you need information on Manual Transmission for the truck chassis, that is a separate document. Same for Manual Transmission rebuild procedures – this crane manual only covers the crane itself.

FAQ

Is this an original OEM manual or a reprint?

It is a direct scan of the original 1989 Furukawa Unic workshop manual. No reprints.

Does it cover the hydraulic system in detail?

Yes, §3 covers telescoping cylinders in detail including disassembly for 2-section through 6-section booms. §5 covers outrigger cylinders with pilot check valve construction. The manual also explains cushion seal function and how to adjust wire ropes for extension/retraction. Page 63 gives turntable bolt tightening order and torque values. You get the full hydraulic circuit understanding from factory engineers. That includes the differential type base construction in §4 and the inner box extension cable installation for five different types. If you need to trace a pressure drop in the outrigger circuit, the piping diagrams on pages 54–56 show every port.

What models are covered in this manual?

The manual lists UR220, UR250, UR260, UR290, UR330, UR360, and UR500. The procedures apply across the UR series with specific sections for 3, 4, 5, and 6-section booms.

Can I use this manual for maintenance on the UR500?

Absolutely. The UR500 is listed on the cover and includes the 6-section boom disassembly procedure and triple cylinder explanation. The outrigger high outrigger section also applies. Page 67 torque specs are the same for all models.

If you are serious about keeping a Furukawa Unic crane running without chasing ghost problems, you need the factory documentation. Access the Factory Manual today and get the real specs on your workbench.