Description

GEHL 1640E 2009 Service Manual

If you have ever tried to rebuild a hydrostatic drive or pull a Yanmar engine using a generic manual, you know the frustration. Cross-threaded bolts, wrong shim stacks, hydraulic leaks that show up after you button it up — that is what happens when someone skips the factory data. This **GEHL 1640E 2009 Service Manual** is the original OEM document used by dealers. 160 pages, no aftermarket garbage, no reprinted copies. It tells you exactly how the machine comes apart and goes back together, with the torque values and clearances that keep it running.

Specifications and Fluid Capacities

The manual opens with a full specs page — including angles like 45.9°, 23.4°, and 100.3° that are used for checking frame alignment and driveline angles. You also get the capacities for hydraulic oil, crankcase, and the cooling system. Do not guess on oil type; the factory specifies the exact grade. Use the wrong weight and you will starve the pump on a cold morning. Specifications are printed in imperial units, so no metric conversion headaches.

3 Critical Safety Procedures You Must Follow

Skid-steers are top-heavy and unforgiving. The manual dedicates a full section to the Mandatory Safety Shutdown Procedure and the Lift Arm Support Device engagement. I have seen techs skip the support step to save ten seconds — that is how you get crushed. The procedure is laid out in numbered steps: raise the lift arm, shut off the engine, remove the key, place the support device on the left cylinder rod, then restart and lower. Page references are given for each warning. If you ignore these pages, you are working under several thousand pounds of steel with no backup.

Does This Manual Cover the Engine?

Yes. The engine section covers the Yanmar diesel used in these loaders. You get removal and installation steps, valve clearance specs, injection pump timing, and cylinder head torque sequences. For example, when you need to replace a head gasket, the manual lists the exact tightening order and torque values. Do not rely on a generic diesel manual — the Yanmar has specific tightening angles that differ from inline engines. Missing those steps means a blown gasket within 50 hours. The manual also includes troubleshooting for low compression and hard starting.

Get the Torque Specs from the Factory

Every threaded fastener in the loader has a specified torque in this manual — from the ROPS capscrews to the hydraulic line fittings. Aftermarket sources often round values or list a range that is too wide. For example, the wheel lug nuts on the 1640E require a specific torque to avoid warping the hub. The manual lists it. I have used these specs on three different 1640E units over the years and never had a fastener come loose or strip. That is the difference between OEM data and a guess. If you want to understand how a Manual Transmission works as a comparison, the loader uses a hydrostatic drive, but the principle of torque application still applies.

ROPS and Lift Arm Support: Factory Procedure

The manual covers raising and lowering the ROPS correctly. It warns you to remove the capscrews on each side of the forward stanchions, lift the ROPS until the lock engages, and never lean on the mast while it is raised. The same section details the Lift Arm Support Device Disengagement — a step that requires you to raise the arm, shut off the engine, remove the key, and then check the solenoid valve before leaving the compartment. These are not suggestions; they are mandatory steps. Missing one can kill you. The manual also explains Relieving Hydraulic Pressure before any line work, a step that aftermarket guides often skip.

Why OEM Documentation Beats Aftermarket

I have seen techs buy a $30 manual from a third party and then call me asking why the bolt pattern does not match. Aftermarket publishers scan out-of-date reprints or combine models that share only a chassis. This manual is the exact document Gehl printed in 2009 for the 1640E and Mustang 2012. It includes the factory revisions (Form No. 917400, Revision A, 08/09). Every page number corresponds to the dealer binder. If you need to order a part, you can reference the factory diagram and get the correct OEM number — not a superseded aftermarket listing. For more background on how automotive repair documentation has evolved, you can read about the history of the Manual Transmission; the same principle of original equipment accuracy applies here.

Related Manuals

If your shop works on other GEHL models, consider these factory documents:

• GEHL Z45 450Z 2012 Service Manual – Factory OEM Specifications”>GEHL Z45 450Z 2012 Service Manual – Factory OEM Specifications
• GEHL SL5635, SL6635 Service Manual – 198-Page Factory OEM”>GEHL SL5635, SL6635 Service Manual – 198-Page Factory OEM
• GEHL SL7810E 2006 Service Manual – OEM Skid-Steer Repair”>GEHL SL7810E 2006 Service Manual – OEM Skid-Steer Repair

Frequently Asked Questions

Is this manual also for the Mustang 2012?

Yes, the manual covers both the Gehl 1640E and the Mustang 2012 skid-steer loaders.

What fuel system specifications are included?

The manual includes all factory specifications for the Yanmar engine including injection timing, fuel pump pressure, and injector testing procedures. You get the exact settings used at the factory, not generic values from aftermarket sources. Page references are provided for each procedure. For example, the fuel system section details the injection pump removal and installation steps with torque values for the injector lines. This is critical because using incorrect torque can cause leaks or injector failure. The manual also includes troubleshooting steps for low power or hard starting, which often trace back to fuel delivery issues. If you are working on the fuel system, this is the only document you should trust.

Every hour you spend on a loader without the factory manual is an hour wasted on guesswork. This 160-page OEM document gives you the exact specs, the right torque, and the safety procedures that protect your life. Get the real factory data and the steps that keep you safe — access the Factory Manual now.