Description

GEHL T650B, T650BD Parts Catalog – What You Get on the Bench

I’ve seen too many guys order a seal kit for the wrong pump because they grabbed a part number off some aftermarket PDF that had the illustration flipped. That mistake costs you half a day and a phone call to the parts house that goes nowhere. This is the GEHL T650B, T650BD Parts Catalog – 78 pages, factory-issued, straight from the GEHL Construction line. It covers the gas and diesel versions of the PowerBox self-propelled paver. If you’re rebuilding a T650B or T650BD screed, swapping a track drive motor, or tracing a hydraulic leak, this is the document you need open on the bench. Not a reprint. Not a scan of a scan. The real thing.

Decal Locations – Where to Find the Serial Plate

Page 3 shows every decal and serial number location. The model and serial plate sits on top of the control console by the manual storage box. Right and left are determined from behind the unit facing forward – GEHL spells that out in the intro because people mix it up. If you’re ordering parts and don’t have the serial number handy, you’re guessing. Guessing on a hydraulic motor replacement gets you a wrong spline count and a track that won’t drive. Get the plate location memorized before you pull anything apart.

Chassis Section – Screed Assembly and Track Drive

The chassis section starts with the Screed Assembly on page 8. Following that you get the right-side backwall group for the T650B gas (page 12) and the T650BD diesel (page 16). Lower Frame & Hopper Group runs from page 24, and the Drive Track Assembly is page 26. That track assembly page is where you’ll find the torque hub breakdown. Need to know if the drive motor bolts are Grade 5 or 8? The hardware spec is in the intro – all cap screws are Grade 5 zinc-plated unless noted. Don’t trust a generic bolt grade chart from the internet. GEHL lists the attaching hardware torque values on the inside back cover.

Electrical Section – Wire Harness Hookup for Both Models

Two pages: T650B gas main wire harness hookup on page 28, T650BD diesel on page 29. The diesel harness differs because of the glow-plug circuit and fuel shutoff solenoid. If you’re splicing in a new harness or chasing a no-start, you need the correct pinout. Aftermarket wiring diagrams often merge the two models into one mess. This manual keeps them separate. That’s why you pay for an OEM document. Get the wiring straight before you apply power – fried ECUs are expensive.

Hydraulic Systems – Plumbing Diagrams for Every Circuit

Seven plumbing subsections: Pump/Reservoir for gas and diesel (pages 30 and 34), Drive Valve/Motors (page 38), Auger & Gates (page 42), Hopper Lift (page 44), and Screed (page 46). Each diagram shows every fitting, hose, and port. When you’re chasing a leak in the auger circuit, you don’t guess which O-ring goes where – you find it on the auger plumbing page. The manual also includes a complete list of abbreviations for fittings (NPTF, ORB, etc.) so you can order the right adapter. Standard attaching hardware torque values are on the inside back cover – use a torque wrench, not a grunt.

Hydraulic Components – Pumps, Motors, and Valves

This section is where the catalog earns its keep. Front piston pump (page 48), rear gear pump (page 50), auger drive pump (page 51), track drive motor and torque hub (pages 52–54), auger drive motor (page 56), screed vibrator motor (page 57), drive control valve (page 58), 7-stack control valve (page 60), auger control valve (page 62), steer control valve (page 64), relief valve (page 65), gate shut-off cylinder (page 65), side gate cylinder (page [DATA NEEDED]). Each component has an exploded view with callouts that match the part numbers in the list. If you need a seal kit for the 7-stack valve, the page gives you the part number for the entire valve assembly plus the individual O-rings and spools. That’s how you avoid ordering the wrong kit.

Audience Fit – Who Should Buy This

Home-garage guys who own a T650B or T650BD and want to service it themselves. Small paving contractors who keep a mechanic on staff. Anybody who’s been burned by a parts counter clerk who says “Oh, those are the same” when they aren’t. The manual is 78 pages – not a thick book, but every page is packed with part numbers, exploded diagrams, and torque specs you won’t find in a generic aftermarket catalog. If you’re a beginner, the intro explains how to read the parts list (hardware indented under the component, abbreviations for washers and nuts). That’s the kind of teaching that keeps you from ordering a bolt without the lock washer.

Source Validity – OEM vs Aftermarket

This is a factory GEHL publication – Form No. 907363, replaces 907304. The part numbers come straight from the manufacturer. Aftermarket catalogs often re-number parts or skip the “As Required” hardware like cotter pins and set screws. GEHL lists those indented under the parent part. The manual even states: “Grease fittings and common attaching hardware… are included in the parts list, indented below the part it is associated with, but NOT illustrated, except where a particular routing or special fastening arrangement MUST be maintained.” That’s the kind of detail a production factory cares about. A reprint house wouldn’t know to include that note. Trust the OEM document, not the third-party screenshot.

FAQ

Does this manual include torque specs for hydraulic fittings?

Standard attaching hardware torque values are on the inside back cover. The manual does not list hydraulic fitting torque separately. You’ll need the fitting type (NPTF, JIC, etc.) and a fitting torque chart from the manufacturer. For cap screws, all are Grade 5 unless noted. Page 26 lists the track drive assembly – if you’re torquing those bolts, use the inside back cover values.

Can I use this to rebuild the screed?

Yes – the Screed Assembly is on page 8 and Screed Plumbing on page 46.

Look at the table of contents: Decal Locations, Chassis, Electrical, Hydraulic Systems, Hydraulic Components. That’s the entire machine broken down into sections you can navigate blind. If you’re ordering parts for a T650BD diesel paver and you need the right pump plumbing, turn to page 34. If the auger won’t lift, check the Hopper Lift Plumbing on page 44. This catalog is the difference between a one-day repair and a three-day headache. Get the original. Access the Factory Manual and keep it on your tablet or print the pages you need. Your parts counter will thank you.

Related manuals you might need: GEHL SL4640, SL4840, SL5640, SL6640 2005 Parts Catalog, GEHL SL7610, SL7710, SL7810 2005 Parts Catalog – OEM Factory Specs, GEHL RS6-34 2013 Parts Catalog – Factory OEM Manual. For background on diesel engine systems, see this Wikipedia article on diesel engines or this Wikipedia article on diesel engines.