Description

GEHL 1660, 1660HD Parts Catalog

If you’ve ever had a forage box down in the middle of harvest because you ordered the wrong unload chain or a bearing that didn’t match the cross conveyor, you know the cost of that mistake. That’s where this GEHL 1660, 1660HD Parts Catalog earns its keep. It’s a straight-up factory document – 44 pages, no aftermarket interpretation, no guesswork. Every exploded view shows exactly which bolt, nut, and shim goes where. You don’t need to wonder if a part superseded; the reference numbers and notes tell you.

Right from page 2, the manual sets the rules: “Right” and “left” are determined from the rear of the unit looking forward. The cross conveyor discharges from the left. That orientation matters when you’re ordering a replacement beater clutch or a cross apron drive sprocket. The manual includes a full table of abbreviations – A/R, FCS, FLN, all of them – so you’re never scratching your head over a line item. And the decal locations? Pages 2 through 5 map every sticker, from the model number decal near the PTO shaft to the safety warnings. If you’re restoring a 1660HD and need to replace faded decals, this catalog tells you the correct part numbers.

Decal Locations and Orientation

Decals aren’t cosmetic – they carry serial numbers, torque warnings, and operating instructions. This catalog dedicates pages 2-5 to decal placement diagrams. The manual specifies that “right” and “left” are from the rear operator position. That’s the same orientation used in all subsequent exploded views. If you skip this section, you might order the wrong decal set or install a beater drive on the wrong side. The decal callouts include part numbers for each sticker, so you can order replacements directly from GEHL without measuring or guessing.

Beaters and Main Apron Drive: Exploded View

Pages 6-7 cover the beaters and main apron drive. The exploded diagram separates the beater shafts, bearings, sprockets, and chain. Each part gets a reference number. Some numbers have a hexagon symbol with a torque value in foot-pounds – for example, the beater drive sprocket retaining bolt torque is called out right on the illustration. That’s one less thing to look up in a separate manual. The parts list includes descriptions like “FCS – Flanged Cap Screw” and “FLN – Flanged Lock Nut.” If you need a replacement beater chain, the catalog lists the chain type and number of links.

Cross Apron and Drive: Ordering the Right Parts

Cross apron and drive components are on pages 8-9. The cross conveyor clutch – belt drive – is on pages 12-13. I’ve seen aftermarket diagrams that lump the cross conveyor and main apron together, leading to wrong belt lengths. This catalog keeps them separate. The belt drive clutch assembly includes the sheave, key, and hardware. The manual notes that unless otherwise specified, cap screws are Grade 5 cadmium plated. Nuts are Grade B for Grade 5 bolts. That matters when you’re torquing fasteners to the values on the inside back cover.

Torque Specs: Page 26 and Inside Back Cover

Torque values are scattered through the catalog – a hexagon number next to a reference number means that’s the torque in foot-pounds for that fastener. The inside back cover provides standard hardware torque specifications for Grade 5 and Grade 8 bolts. Page 26, the gearboxes section, lists the torque for the gearbox mounting bolts and the PTO shaft coupling. If you’re rebuilding a 1660’s gearbox, that page saves you from stripping a housing. You don’t need to hunt through a separate service manual for torque – it’s baked into the parts diagram.

Optional Hydraulic Drive and the 12″ Extension

Pages 33-34 cover the optional 12″ extension and the optional hydraulic drive. The hydraulic drive section includes the pump, motor, hoses, and mounting bracket. The parts list uses the same reference number system, so you can order a replacement hydraulic motor without disassembling the whole unit to get a serial number. The tie-down kit is on page 32 – useful if you transport the forage box on a flatbed. PTO parts are on page 31. Having all these optional sections in one catalog means you don’t need separate documentation for add-ons.

Source Authenticity: Factory Parts Catalog

This is GEHL’s own parts catalog, form number 909859 Revision B. It’s not a reprint or a third-party compilation. The exploded views are drawn to factory spec, and the part numbers are current as of the publication date. Aftermarket parts catalogs often substitute generic fasteners or omit the “A/R – As Required” notation for shims and seals. This manual includes both an alphabetical index (page 35) and a numerical index (pages 36-39) so you can cross-reference part numbers from the old part to the new. That’s something a generic PDF from a parts house never gives you.

Related Manuals

If you’re working on other GEHL equipment, check out the GEHL SL4640, SL4840, SL5640, SL6640 2005 Parts Catalog for skid loaders. The GEHL SL7610, SL7710, SL7810 2005 Parts Catalog – OEM Factory Specs covers the larger models. For compact excavators, the GEHL RS6-34 2013 Parts Catalog – Factory OEM Manual has the same level of detail. All factory direct, no fluff.

For background on how these engines and drivelines work, see this Wikipedia article on diesel engines – the fundamentals of torque and power delivery that drive these forage boxes.

Frequently Asked Questions

Does this parts catalog include torque specifications for all fasteners?

Standard hardware torque values are on the inside back cover. Specific fasteners in the exploded views have torque values in foot-pounds indicated by a hexagon symbol next to the reference number. The gearboxes section on page 26 also lists torque for mounting bolts and the PTO shaft coupling.

Can I use this catalog to order parts for a 1660HD if my serial number is missing?

Yes.

If you’re tired of playing the parts-number guessing game, grab this manual. Access the Factory Manual and get the real GEHL data on your screen.