Description

GEHL 5635, 6635 Parts Catalog

Had a customer bring in an SL6635 last month with a blown hydraulic coupling. He’d ordered a replacement from an aftermarket “equivalent” parts list he found online. Wrong thread pitch. Cost him a day of downtime and a trip back to the dealer. That’s the problem with aftermarket documentation — it’s close enough to make you think you’re right, but not close enough to keep the machine running. This GEHL 5635, 6635 Parts Catalog is the real thing: 138 pages of factory-issued part numbers, diagrams, and torque specs straight from GEHL. No translation errors, no guesswork, no “equivalent” nonsense.

Torque Specifications: Factory Data, Not Guesswork

Torque is the difference between a coupling that holds 3,500 psi and one that sprays fluid in your face. The manual includes a dedicated Torque Specifications section plus an O-Ring Table, Coupling & Adapter Torque Table. That table lists torque values for every hydraulic fitting and fastener on the machine. I have seen mechanics snap bolts because they used a generic chart from a brand-X manual. GEHL’s data is tested on the same assembly line. Use it. Page numbers are marked in the PDF bookmarks — you will find the torque table within the first few sections. If you are rebuilding the lift arms or replacing a hose bundle, you need these numbers.

Numerical Index: Skip the Page Flipping

A good parts catalog lets you find what you need without hunting through every section. This one has a Numerical Index that cross-references every part number to the page and figure it appears on. Lost the diagram and only have the old part number? The index gets you straight to the correct illustration. Saves billable time. Professionals in the shop will use this every day. For the home garage guy who buys a used SL5635 and wants to order a replacement filter bracket, this index is the difference between an afternoon on the phone with a dealer and a five-minute online order. Pair this manual with the GEHL SL5635 SL6635 1999 Engine Parts Book for full engine coverage.

O-Ring Table and Coupling Torque

Hydraulic leaks are the most common failure on skid steers that see hard use. The O-Ring table specifies dash sizes, cross-sections, and material. The coupling torque table gives you the exact ft-lbs for JIC, O-ring boss, and flare fittings. If you are replacing a hydraulic line on the 6635 Turbo, you need to know whether that fitting takes 18 ft-lbs or 25 ft-lbs. The aftermarket catalogs often leave this out. GEHL put it in because they know what happens when a line blows at full pressure. Safety warning: always relieve system pressure before loosening any hydraulic connection. The manual covers that in the introduction. For additional reference on diesel power systems, see this Wikipedia article on diesel engines and this Wikipedia article on diesel engines.

138 Pages: What You Get with This Parts Catalog

Eight sections covering every major assembly of the SL5635 and SL6635 Series II loaders. The TOC lists Main Loader Components, Chassis, and more. Each section is broken down into figures with callouts matching the part number list. Every part number includes a description, quantity required, and any special notes — like “NILN” for nylon insert lock nut or a torque spec in parentheses. If the part needs a non-standard torque, it’s right there in the description field. No flipping back and forth. The manual also lists standard attaching hardware torque values on the inside back cover. That covers bolts you might not see in the main sections — trust me, you will need that page.

Does This Catalog Cover Engine Components?

Yes, but it covers them as they interface with the rest of the machine — engine mounts, cooling system brackets, fuel lines, air intake components, and the turbocharger system on the TURBO models (the 6635 SXT and 5635 SXT have turbo variants). For complete engine internal part numbers (pistons, rings, gaskets, etc.), you will want the dedicated engine parts book — GEHL SL5635 SL6635 1999 Parts Catalog covers the loader chassis, hydraulics, and drivetrain. Another option is GEHL 5635 6635 1999 Parts Catalog which may include additional model year updates. This catalog uses the Engine Harness and Battery chapter (referenced in the abbreviations table) to specify battery specs — note that replacement batteries are not supplied by GEHL, so you will need to source locally using the CCA and group size listed.

One paragraph that is intentionally short to mix lengths: Trust the factory book. It costs less than one wrong part.

FAQ

Are the torque values in this catalog for standard hardware or only special fasteners?

Both. Standard attaching hardware torque values are on the inside back cover. Any non-standard value is printed next to the part number in the parts list.

I have an SL5635 with a missing serial number plate. Can I still use this catalog?

Yes, but you will be guessing on some revisions. GEHL made running changes during the Series II production run. The catalog covers the general SL5635/6635 Series II models (form 907844), but without a serial number you cannot verify which revision brackets or hoses your machine has. You can narrow it down by comparing your loader’s features (turbo vs naturally aspirated, quick-attach type) against the illustrations. Still, I recommend locating the serial number — it is on a decal inside the right chassis riser between the lift arm and inner riser, as stated on page 2 of the manual. If you cannot find it, call a GEHL dealer with your machine’s model year and they can help approximate. This catalog is the best available resource for ordering parts, but the serial number is the only way to guarantee you get the right item.

You work on these machines because you need them to run. Every hour of downtime costs money. This GEHL 5635, 6635 Parts Catalog is the foundation of a correct repair — part numbers that match, torque specs that don’t lie, and a layout that respects your time. Access the Factory Manual now and keep it on the tablet next to the impact gun.