Description

GEHL SL6620, SL6625 Workshop Manual

I’ve lost count of how many skid loaders I’ve had torn down to the frame because some aftermarket manual had the wrong torque spec. That’s not a risk you take with a GEHL SL6620, SL6625 Workshop Manual. This is the same 114-page binder the dealer techs use. It’s OEM, not a reprint. Page 3 has the torque values you need for fasteners across the entire machine – and I mean every fastener that matters, not just engine bolts.

Torque Values: Page 3 Specs You Cannot Skip

Torque is the one spec that separates a reliable rebuild from a leaky headache. Section 1 of this GEHL manual dedicates page 3 to torque values, right up front. No hunting through appendixes. You get the numbers for engine mounting bolts, drive chain sprocket fasteners, brake hardware – all in imperial units. Lay the book flat next to your torque wrench and follow the sequence. I’ve seen guys strip axle bolts on SL6625s because they guessed. The manual lists the exact values; use them.

Engine Specs and Lubrication Schedule

Section 2 gives you the engine specifications – displacement, oil capacity, firing order, the works. But the part I use most is Section 5 on lubrication. It covers chaincases, engine crankcase, hydraulic oil reservoir, and planetary gearcase. You get the correct oil viscosity index for your operating temperature. That matters in San Antonio summers. The manual also shows greasing points and intervals. Nothing vague – it tells you which grease fitting gets how many pumps.

Section 7 Drive: Chains, Brakes, and Adjustment Procedures

Drive chains and brakes take the hardest abuse on a skid loader. Section 7 walks through disc brake adjustment, brake pad replacement, and chain removal and installation. The manual specifies how to check chain sag and where to measure it. It also covers the traction drive T-bar, neutral adjustment, and servo adjustment. If your SL6620 creeps in neutral, you need the procedure on page 26. The manual doesn’t assume you know which rod to turn – it shows you.

Does the Manual Cover the Hydrostatic System?

Yes. Section 8 is hydrostatic system troubleshooting and service. It explains neutral, forward, reverse operation and how to test charge pressure. Page 48 shows the drive motor and tandem pump service steps. If you’re losing power or the machine won’t move right, start with the troubleshooting chart on pages 45–47. The manual gives you the test points and pressure ranges. No guesswork. It also covers the control linkage adjustment if the hydrostat feels off from the hand controls.

Source Authenticity: Why OEM Beats Aftermarket

This manual comes from the factory print – GEHL’s own shop manual. The decal section (Section 4) shows exact locations for warning labels and part numbers. The safety section (Section 3) covers restraint bar switches, in-seat safety switches before and after serial number 2651. An aftermarket book would lump those together. This manual treats them separately because the wiring changed. If you need to replace a floor plate or a console, Section 6 has the removal sequence. The detail is in the OEM data, not a copy.

Related manuals for other GEHL skid loaders: GEHL 1083, 883 Workshop Manual – OEM Factory Shop Manual, GEHL SL4510 SL4610 Workshop Manual – Factory OEM 104-Page Guide, Gehl 5625 SL5625 Skid Loader Workshop Manual SN 8868+.

For general reference on drivetrain basics, you can check Manual Transmission theory, but this manual covers the hydrostatic drive that’s actually in the machine. There’s also a good explanation of Manual Transmission principles online, though the SL6625 uses a tandem pump and drive motors, not a gearbox.

Does this manual cover both the SL6620 and SL6625?

Yes, it covers both models in one binder.

What safety information is included in the manual?

Section 3 spans pages 5 and 6 with safety warnings specific to the 6620 series. Section 4 covers decal locations and new decal application, including the exact part numbers for warning labels. The chassis section (Section 6) includes detailed procedures for the in-seat safety switch (with separate instructions for machines before and after S.N. 2651), the restraint bar switch, and seat mounting. If you’re replacing a seat or switch, the manual tells you the wiring pin-out and bracket orientation. That level of detail prevents you from bypassing a safety circuit accidentally. The overhead guard removal and installation steps are also in Section 6, with torque sequences for the mounting bolts. This is the kind of information that keeps you from getting crushed by a lift arm because a sensor wasn’t positioned correctly. I always tell guys: read Section 3 and 4 before you even pull the floor plate.

If you’re about to tear into a 6620 series skid loader, get the right documentation first. Access the Factory Manual from AutoRepairManuals and keep it on the bench next to your torque wrench.