Description

GEHL SL4640, SL4840, SL5640, SL6640 Service Manual

I’ve been turning wrenches for 28 years, and I’ve seen more backyard repairs go sideways because somebody skipped the factory book. If you’re working on a GEHL SL4640, SL4840, SL5640, SL6640 Service Manual is the one document that keeps you from guessing. This is the same manual Gehl puts in the toolbox of every new loader. 104 pages of straight factory data, not some aftermarket translation that rounds off torque values to the nearest 10 ft-lb.

You want to know why the parking brake won’t release? Or why the Hydraloc™ interlock keeps tripping? Start here. The manual walks you through the mandatory safety shutdown procedure, the safety interlock system test, and the exact steps to adjust the drive chains. No fluff, no filler. Just the specs Gehl stamped on the parts.

GEHL SL4640-SL6640 Service Manual: 104 Pages of Factory Specs

This manual covers four models: SL4640, SL4840, SL5640, and SL6640. The table of contents lists every section you need — from Introduction and Safety all the way through Torque Specifications on page 93 and the Index. The Service chapter alone runs from page 47 to 64, covering chaincase oil changes, drive chain tension, engine air cleaner service, hydraulic oil filter changes, and cooling system cleaning. You get the full maintenance log and troubleshooting charts. If you’re tracking hours, the hourmeter is explained in the right panel section.

Need the charge pressure for the hydraulic system? That’s in the Specifications chapter starting on page 79. But I’m not going to spoon-feed you every page number. Open the book. It’s all there.

Torque Specs and Fluid Capacities: Why This Manual Matters

Torque values on a skid-steer are not suggestions. Wheel nuts, lift arm pivots, engine mounting hardware — every one has a specific ft-lb rating. This manual gives you a dedicated Torque Specifications section on page 93. It also lists fluid capacities for chaincases, hydraulic system, and engine oil. You won’t find that in a generic repair guide. Aftermarket manuals often copy the numbers but miss the tightening sequence. Gehl’s factory manual includes the sequence notes. I’ve seen a hydraulic line blow because a technician used a generic torque value. Don’t be that guy.

Safety Interlock System and Hydraloc™: Not Optional

The controls and safety equipment chapter covers the mandatory safety shutdown procedure, the operator restraint bar, the upper-torso restraint, and the Hydraloc™ system. It also includes the testing procedure for the safety interlock system. If you bypass that test, you’re working on a machine that could move unexpectedly. The manual also details the parking brake, the horn, and the rear window emergency exit. These are the things you check before you even start the engine. The Lift Arm Support Device engagement and disengagement is covered step by step — that’s a critical safety step when you’re underneath the arms.

Does This Manual Cover the Brake System?

Yes. The parking brake is listed in the Controls and Safety Equipment chapter. The manual explains how to test it and how to adjust it. The brake system is part of the safety interlock loop — if the brake isn’t engaged, the Hydraloc™ won’t release. For detailed brake service beyond operator checks, you’d need the full service manual, but this operator’s manual gives you the adjustment specs and the safety checks. If you’re doing a brake job, you’ll want the related GEHL SL4640-SL6640 2007 Parts Catalog – OEM Engine Parts for the correct part numbers.

3 Reasons to Stick with OEM Documentation

First, the wiring diagrams and hydraulic schematics in aftermarket manuals are often redrawn and missing details. This manual uses Gehl’s original figures — Figure 11 (Right Panel) and Figure 12 (T-Bar Controls) are exact. Second, the torque values are certified to Gehl’s QA standards. Third, the troubleshooting section is written by the engineers who designed the machine. For example, the manual includes a specific test for the safety interlock system that no third-party guide covers. If you’re swapping a Manual Transmission or rebuilding the engine, you need the factory flow charts. The Manual Transmission section in a generic book won’t tell you the Hydraloc™ lockout procedure.

For additional parts diagrams, check the GEHL SL4640 SL4840 SL5640 2009 Parts Catalog Manual and the GEHL SL4640, SL4840, SL5640, SL6640 2005 Parts Catalog.

Service Routine: Chaincases, Drive Chains, and Cooling

The Service chapter covers the chaincase oil check and drain, drive chain tension adjustment, and the cooling system cleaning procedure. The manual tells you how to access the engine compartment and tilt back the ROPS/FOPS. It also includes the alternator/fan belt adjustment and the wheel nut torque. If you’re doing a hydraulic oil change, the manual specifies the filter part number and the oil capacity. The maintenance log at the back lets you record hours and service intervals. This is the kind of documentation that keeps a loader running 10,000 hours without a major failure.

Is this manual the same as the one dealers use?

Yes. It’s the factory operator’s manual Gehl ships with the loader.

What if I need repair procedures beyond operator maintenance?

This manual covers operator-level service like chain tension, hydraulic oil changes, and belt adjustments. For major engine or transmission rebuilds, you’ll want the full service manual. But the torque specs and safety procedures are identical. The manual also includes troubleshooting charts and a maintenance log. If you’re doing your own routine service, this is the document you need. The safety interlock system test alone is worth the price. Access the Factory Manual and keep it in your tablet or print it out for the shop.

You’ve got a Gehl skid-steer that needs proper care. Don’t trust a random PDF from a forum. This is the factory document. Access the Factory Manual now and bolt it to your workbench.