Description

John Deere 493, 494, 594, 693, 693 SH 1999 Parts Catalog

If you’ve ever ordered a part for a John Deere 493, 494, 594, 693, or 693 SH corn head and got the wrong one because you guessed from an aftermarket diagram, you know the pain. I’ve seen guys bolt on a gathering chain that didn’t match the serial number break – then spend a day redoing it. That’s why this 1999 Parts Catalog exists. It’s the same book the dealer parts counter uses, 139 pages of OEM grid drawings and part numbers printed by Deere themselves. Not a third-party rehash with missing callouts.

Before you touch a wrench, you need the right part. This catalog gives you the exploded views with each item keyed to a reference number. Look up the grid (A02 through L25, plus alphabetical index) and you’ll see the exact fastener, seal, or subassembly. The serial number plate location? Page 2 of the manual tells you it’s on the left-hand side of the frame, and how to decode the model and factory code. That alone keeps you from ordering a 694 part when you have a 493.

Grid System and Part Number Index

The TOC is laid out in grids – A, B, C, D, E, F, and L. Each grid covers a specific area of the corn head: gathering chains, deck plates, backshafts, auger floors, slip clutches, and more. You go to the grid that matches your assembly, find the illustration, and pick the part number. For example, grid B covers backshafts for models 494 and 592, while grid D includes adjustable deck plate cylinder repair kits. The alphabetical index at the back cross-references every component name to its grid location. That means you don’t flip through 139 pages blindly.

Need the charge pressure? Page 73. Actually, page numbers in a parts catalog aren’t sequential like a service manual – you navigate by grid letters. But the important thing: every fastener is identified by SAE grade or property class. Look for “HS SAE 8” or “HS 10.9” in the bolt descriptions. That matters when you’re replacing a cap screw on the row unit – use the wrong grade and it’ll shear under load.

Does This Parts Catalog Cover the 693 SH?

Yes. The 693 SH (Special Hard) is listed explicitly in the model table on page 1, with manufacturing dates from 1993 onward. The same grids apply, but note that later serial number breaks may have different supersessions. The catalog includes serial number ranges for each part – for example, (660201- ) or (660400- ). Always check the serial number of your corn head against the listing. If you have a machine built after 567201, the serial number format changes; page 2 explains the new coding. Don’t skip that step.

Bolt Strength Identification – Not Optional

Inside the front matter (page 3), there’s a table explaining bolt and cap screw strength identification. High-strength bolts are marked “HS SAE 8” or “HS 10.9” – those are not decorative. I’ve seen stripped threads and broken ears on adjustable deck plates from guys using grade 5 bolts where grade 8 was called for. The catalog tells you which fasteners need the higher rating. If you’re rebuilding a 693 SH gathering unit, pay attention to the description next to each bolt callout. The difference between a $2 bolt and a $200 repair.

Also, the JDM Remanufactured Components note on page 3 warns that service parts may not fit remanufactured units because the redesign changes dimensions. If you’re repairing a reman head, verify the part number against the original serial number. That note is easy to miss, but it’s there.

Audience Fit – Who Needs This Manual

This is for the farm shop mechanic or owner-operator who keeps a 90 Series corn head running through harvest. You’re not rebuilding the engine – you’re replacing gathering chains, deck plates, backshafts, and stalk rolls. The grids are designed so you can point to the part, call the dealer or order online, and get exactly what the factory intended. If you’re a DIY guy who bought a used 594 or 693 and wants to restore it, this catalog saves you the cross-referencing headache. You’ll also find the John Deere 90 series corn heads parts catalog that covers other models.

Related manuals that work alongside this one: John Deere 2130 Parts Catalog – Factory Specs for Correct Part Identification and John Deere 4500, 4600, 4700 2000 Parts Catalog – OEM Grid Index, plus John Deere 9400, 9100, 9200, 9300 Parts Catalog – OEM Factory. For background on how these engines (diesel) work, check this Wikipedia article on diesel engines or this Wikipedia article on diesel engines.

FAQ

Does the catalog show torque specs for bolts?

No. This is a parts catalog, not a service manual. It identifies part numbers and bolt grades, but not torque values. For torque specs, you need the corresponding John Deere technical manual.

How do I locate a specific part if I only have the name?

Use the alphabetical index at the back. Every component – from “ACTIVE HEIGHT CONTROL, INNER GATHERER POINTS” to “BARREL, STALK ROLL” – is listed alphabetically with its grid letter and figure number. For example, “BACKSHAFT (594, 692 AND 693)” directs you to grid B. Once you find the grid, the illustration shows the part with a reference number. Match that to the parts list for the description and OEM number. If the part has a serial number break, pay attention to the range. This manual groups parts by model and serial number, so you won’t order a 494 backshaft for a 693.

Access the Factory Manual if you want to stop guessing which gathering chain fits your 693 SH. The 1999 edition is the last major update before the 90 Series was phased out, so it includes all supersessions and corrections. Keep it in the shop tablet or print the grids you need. Your wallet and your downtime will thank you.