Description

Champion 720 1991 Training Manual – Factory Specs for Series III

If you are working on a Champion 720 1991 Training Manual territory, the one thing you do not want is a torque spec pulled from a forum or a reprinted aftermarket sheet. I have seen a front axle lean pin snap because someone used 250 ft-lb instead of 210. This manual is the factory document Champion issued to its own service trainees in 1991. 59 pages of oil circuit diagrams, valve body cross-sections, and clutch pack assembly sequences. It teaches the theory first, then the procedure. For a grader, that matters.

Front Axle: Oscillation, Leaning Wheel and Toe-in – Page 8

Page 8 covers the front axle oscillation limits and the leaning wheel adjustment on models 710 through 750A – and the 720 falls right in that range. Champion gives you the toe-in specification in inches (not millimeters) and the procedure for setting the leaning angle. If you skip the oscillation check, you will wear out the kingpin bushings fast. This section also shows the difference between the standard axle and the 780/780A version on page 10. That matters when you order a replacement spindle.

Main Hydraulic System: Valve Stack Breakdown – Page 14

The main hydraulic system chapter starts on page 14. It walks through the main relief valve and cushion valve on page 16, then the counterbalance valve and power tilt lock valve on page 18. Each valve is drawn with its internal spool positions and spring settings. There is no generic “remove and replace” – the manual explains what each valve does in the circuit so you can diagnose a drift or a lag. Page 20 covers the solenoid-operated valves. If you have ever chased a dead implement function that turned out to be a stuck spool, you know why this matters.

Circle Timing and Set-Up – Page 26

Circle timing is one of those jobs that looks simple until you mess it up. Page 26 shows the timing mark alignment and the setting for the drawbar and moldboard assembly. Champion includes the fixed point hi-lift (page 22) and the Moveable Point Blade Lift System (MPLS) on page 24. The manual makes you understand the relationship between the circle drive motor and the moldboard shift. Mis-time the circle and the blade will not hold its angle under load. That is a field fix you do not want.

Model 8400 Transmission Oil Circuits – Pages 32 through 38

This might be the most valuable section for anyone rebuilding or troubleshooting the transmission. Page 32 introduces the 8400 transmission assembly. Pages 34, 36, and 38 show the oil circuit in neutral, first forward, and first reverse. Each page has a flow diagram with arrows for oil path. You can trace the pressure to the clutch packs and see where the lube circuit splits off. If you have a burned pack, this is how you identify which control valve is leaking. The double clutch pack on page 40 complements it. Use this in combination with the Manual Transmission section in the shop manual for shift yoke specs.

Oil Disc Brakes – Accumulator Style – Page 52

Brakes on a grader are not optional. Page 52 details the accumulator-style oil disc brake system. It explains the charging valve, the accumulator pre-charge, and the brake release pressure. The manual also covers the standard oil disc brakes on page 50 and the service brake hydraulic circuit on page 48. If you get the accumulator charge wrong, the brakes will drag or not release. Champion specifies the nitrogen pre-charge in psi – that number is not in any aftermarket manual I have seen.

Source Validity: Factory Print vs. Aftermarket Reprint

This is an original Champion Road Machinery Limited publication from 1991. Printed on recycled paper (they wrote it right on the cover). The page numbering matches the factory binder. Aftermarket manuals often crop the diagrams, rearrange the chapters, or drop the torque tables. This one has the original Table of Contents on page 3 and the abbreviation list (R.H., L.H., rpm, psi, gpm, MPLS) on page 4. The Champion 720, 710A, 780, 780A 1991 Training Manual – Factory Specs is part of the same training series. If you need the broader service procedures, grab the Champion 700 Series Grader Series III Service Training Manual which covers the entire 700 line with more repair detail. For technicians who want the core theory, this training manual is the foundation.

Audience Fit: Who Needs This Manual

Professional mechanics who bill by the hour will save time by reading the oil circuit diagrams before pulling the transmission. DIY grader owners (yes, there are private owners with a 720 in their equipment yard) will avoid breaking expensive castings. Beginners should pair this with the Champion Road Machinery 700 Series Service Training to understand safety warnings – the manual itself says on page 1: “READ THE SHOP MANUAL FOR SAFETY WARNINGS.” This is not a substitute for the full shop manual, but it is the missing link between theory and practice. If you are working on the final drive (pages 42-44 for double reduction or SR30/SR40), the training manual explains the lock/unlock differential flow – something that is rarely clear in a parts catalog.

FAQ

Q: Is this manual for the 720 only, or does it cover other models?

A: It covers the 720 Series III specifically, with some overlap on front axle for 710-750A and 780/780A.

Q: Can I use this manual to rebuild the 8400 transmission on my Champion grader?

A: Yes. Pages 32 through 38 give you the oil circuit diagrams for neutral, first forward, and first reverse. Page 40 covers the double clutch pack. You will still need the shop manual for clearance specs and special tools, but for understanding the hydraulic flow that causes shifting problems, this is the document. The training manual explains why the transmission shifts the way it does – not just what to remove. Combine it with the Manual Transmission theory section in a standard powertrain textbook if you need more background on clutch pack operation.

This 1991 Training Manual is not a reprint or a scan of a scan – it is a clean PDF from the original binder. 59 pages, factory diagrams, no missing pages. If you need to service the hydraulic system, set the circle timing, or rebuild the final drive on a Champion 720, you need the factory document. Access the Factory Manual and keep it on your tablet next to the workbench.