Description

Takeuchi TB 108 Workshop Manual – The Only Specs That Matter

You’re in the middle of a track tension adjustment on a Takeuchi TB 108 Workshop Manual and the spec sheet you printed from the internet says 150 ft-lbs on the idler bolt. That number is wrong. I’ve seen guys snap bolts with that figure. This manual gives you the factory number – the one Takeuchi’s engineers stamped on the drawing. It’s 355 pages of specs you can trust.

I’ve torqued more head bolts than most people have had hot meals. The difference between a job that holds and a comeback call is whether you use the right torque value. This OEM manual was printed by Takeuchi, not some aftermarket outfit that copied a copy. The hydraulic pressures, the travel motor disassembly steps, the final drive gear backlash – it’s all here. No guesswork.

Foreword and Machine Orientation

The manual opens with a foreword that tells you exactly who this is for – “persons who engage in maintenance operations.” That’s you. It also defines front and rear based on the dozer blade and travel motors. Don’t skip that. I’ve seen techs tear down a track motor on the wrong side because they assumed the cab was front. The serial number location is called out on page 1. Write it down before you start ordering parts.

7 Systems Covered in This Workshop Manual

This isn’t a quick reference. You get full coverage of the engine, hydraulic system, travel and swing motors, undercarriage, electrical, boom and arm, and controls. Each section starts with a list of required tools – wrenches, pullers, torque wrench, pressure gauges. The hydraulic chapter includes bleed procedures for the cylinders. Page 5 has the actual bleeding steps: run the engine slow, extend and contract cylinders 4 or 5 times, stop 100 mm before stroke end. Do not extend them completely. That kind of detail keeps you from damaging the seals.

Bleeding Air from the Hydraulic Cylinders

Bleeding air is one of the most skipped steps. People button up a pump swap and wonder why the boom drifts. The manual tells you to run the engine at slow, cycle the cylinders to 100 mm before the stroke end, then repeat at full throttle. That sequence matters. Ignore it and you’ll have spongy controls. The manual also warns: do not extend the piston rods completely until the last step. That’s a safety issue. Air compresses; oil doesn’t. A rod that slams into the end cap can crack the cylinder.

Torque Specs and Special Tightening

Every major fastener in this manual has a torque spec listed. Not a range – a specific number with a required tightening pattern. The travel motor mounting bolts, the swing gear bolts, the track adjuster locknut. I’ve had to helicoil more threaded holes because someone went by feel. The manual uses the symbol for special tightening torque. Pay attention. Need the charge pressure? Page 73 has the test port location and the psi range. That page is gold for a hydrostat system. Do not trust aftermarket PDFs for this.

Source Authenticity: OEM vs Aftermarket

This manual is the original Takeuchi workshop manual, distributed by ClassicMachinery.net. It’s not a reprint of a copy. The page numbering uses chapter codes – II-8, II-9-1 for additions. That structure is from Takeuchi, not a generic layout. Aftermarket manuals often skip the revision tracking and the symbolic warnings. Here you get the same document the dealers use. If you’re buying a used TB 108 and need to verify maintenance history, this manual gives you the factory standards to check against.

Does This Manual Cover the Fuel System?

Yes – the engine section includes injection pump timing, injector removal, and governor adjustments. But don’t expect a textbook on diesel theory. This is a service manual, not a training course. It gives you step-by-step replacement procedures with torque values for injection lines and fittings. If you need to rebuild the pump, you’ll need a specialized injection shop manual. For everything else on the TB 108 – the undercarriage, swing gear, final drives, hydraulics – this is the only document you need.

3 Reasons to Choose OEM Documentation

1. Torque values that match engineering drawings, not internet forums.
2. Bleed and test procedures that prevent air lock and component damage.
3. Serial number-specific information – the manual covers serial numbers starting at 10820001.

I’ve been burned by aftermarket manuals that mix up metric and imperial units. This manual uses both, but the torque chart clearly marks which is which. No ambiguity.

If you’re working on a compact excavator and want to avoid a $2,000 repair bill because you guessed a spec, get the factory document. Related manuals you might need for other Takeuchi models include Takeuchi TB28FR Workshop Manual – OEM Factory Specs for Compact Excavator, Takeuchi TB280FR Workshop Manual – 298-Page OEM Factory Service Guide, and Takeuchi TB250 Workshop Manual – 352 Pages of OEM Specs. For general knowledge on drivetrain fundamentals, you can reference Manual Transmission design principles, though this excavator uses hydrostatic drives. Another useful external resource is Manual Transmission theory for understanding gear ratios.

Bottom line: You need the factory specs to keep this excavator running. Access the Factory Manual and print the pages you need. Keep it on the bench, not buried in a drawer.

Is this the same manual the dealer uses?

Yes. It is the original Takeuchi workshop manual distributed by ClassicMachinery.net.

What if I need torque specs for the swing motor mounting bolts?

The manual includes a torque specification chart for all critical fasteners. The swing motor bolt torque is listed in the ‘Engine and Hydraulic’ section. I’ve seen these bolts under-torqued and the motor walks out of alignment. Factory spec is non-negotiable. You’ll find the exact value in the torque table, along with the required tightening pattern. Never use a generic bolt chart for this.

Does this manual cover the undercarriage?

Yes. There’s a full section on track tension, idler adjustments, and final drive removal. The track adjuster locknut torque is given in ft-lbs.

Why should I trust this manual over a free PDF?

Free PDFs often skip pages, have blurred torque values, or mix revision levels. This is a clean, complete scan of the factory print. The page numbering and revision codes are intact. It’s the same document a dealer technician would use.