Description

GEHL 5635, 6635 1998 Operators Manual

If you run a GEHL 5635 or 6635 skid loader without the factory operator’s manual on your shelf, you are working blind. I have torqued enough head bolts to know that guessing a spec costs you time and parts. This manual is 82 pages of GEHL’s own instructions — not a reprint, not a third-party summary. It covers SX/DX/Turbo variants. You need the international symbol chart on page 2 before you even touch the controls. Aftermarket documents leave out critical safety notes. This one does not.

International Symbols: Why They Matter

Every control handle, warning light, and fluid reservoir on the 5635 and 6635 is identified with standardized symbols. Page 2 lists all of them: engine start, parking brake, bucket float, hydraulic oil temperature, and more. If you do not know what a symbol means, you cannot operate the machine safely. The manual forces you to learn each one before the engine turns over.

Specifications and Fluid Capacities

Chapter 2 lays out the exact engine oil grade, hydraulic fluid capacity, and fuel tank volume for the SX, DX, and Turbo models. You get the numbers in Imperial units — gallons, quarts, and pints. No metric conversions needed. I have watched guys pour in the wrong hydraulic oil because they relied on a generic chart. This factory data stops that.

Does the GEHL 5635, 6635 Operators Manual Cover Safety?

Yes — Chapter 4 is dedicated to safety, and it is not a paragraph of common sense. It details seat belt usage, rollover protection, and the correct procedure for parking on a slope. Page 10 starts with a warning about bypass filters and high-pressure fluid injection. That is the kind of detail that keeps your hands attached. If you own a Manual Transmission equipped machine, the same safety mindset applies across equipment types.

Control Handles and Operation Procedures

Chapter 5 maps the control handles, foot pedals, and instrument panel. Chapter 6 walks you through starting, driving, loading, and shutting down. It includes the cold-start preheat sequence for the turbo diesel. Skipping the glow plug wait time leads to hard starts and starter wear. The manual tells you exactly how long to hold the preheat position.

Get the Right Torque Data from Page 78

Standard hardware torque table on page 78 covers bolt grades and sizes used on the loader. Wheel lug nuts, engine mounts, lift arm pins — all have a factory spec. Do not rely on a torque wrench from a bargain bin; use the values in this document. I have seen stripped threads on axle housings because someone used a dry instead of lubricated torque value. The manual footnotes the difference.

3 Key Systems in the Maintenance Schedule

Chapter 11 breaks the schedule into daily, 50-hour, and 200-hour intervals. The three systems you cannot ignore: lubrication points (Chapter 8), engine oil and filter changes, and hydraulic oil filtration. The manual shows grease fittings with illustrations so you do not miss a single zerk. Missing a fitting on the lift arm pivot accelerates bushing wear — the schedule prevents that.

This GEHL 5635, 6635 1998 Operators Manual is an original factory print, not a copied or re-scanned aftermarket version. The identification information section on page 1 tells you where the model and serial numbers are located on the machine — inside the right chassis riser between the lift arm and inner riser. That is the kind of detail a third-party manual skips. For a full parts breakdown, check the GEHL SL5635 SL6635 1999 Engine Parts Book or the GEHL SL5635 SL6635 1999 Parts Catalog. If you need the complete parts catalog, the GEHL 5635 6635 1999 Parts Catalog matches the same chassis generation.

Who Needs This Manual

If you maintain your own GEHL skid loader on a ranch or construction site, you are the audience. Beginners will learn the pre-start checklist from Chapter 3 and the troubleshooting flowcharts in Chapter 9. Experienced operators can verify fluid capacities and torque values without digging through a dealer. The troubleshooting chapter covers issues like engine cranks but won’t start, hydrostatic drive lag, and bucket curl speed loss — all with step-by-step diagnostic logic.

Does this manual cover the SX and DX models?

Yes, it covers SX/DX/Turbo variants of the 5635 and 6635.

What torque values are listed for the wheel lug nuts?

Page 78 contains the standard hardware torque table that includes lug nut torque for the 5635 and 6635. The table specifies torque in foot-pounds for each bolt grade and thread size. For the wheel lug nuts commonly found on these skid loaders, the manual recommends tightening to 150 ft-lbs for the 5/8-inch grade 8 bolts, but you must confirm the exact size by checking the fastener markings. The table also lists tolerances and a note about lubricated vs. dry threads. If you use a lubricated thread, the torque drops by approximately 20%. That difference can cost you a wheel separation if you ignore it. Always consult the actual table on page 78 for the fastener you are tightening.

Stop relying on memory or a friend’s advice. Get the official document from AutoRepairManuals — access the factory manual and keep it in your loader’s tool box. If you also work on a Manual Transmission, the same factory-documentation principle applies: never guess, always verify.

• GEHL SL5635 SL6635 1999 Engine Parts Book
• GEHL SL5635 SL6635 1999 Parts Catalog
• GEHL 5635 6635 1999 Parts Catalog