McCormick-Deering Tractor Disc Harrow No. 10-A
McCormick-Deering Tractor Disc Harrow No. 10-A
Small to mid-sized disc-harrows are a most useful tillage implement. Some farmers consider them indispensable. Discs such as the McD 10-A may be used with either tractors or big hitches of work horses. This tool will cut both plowed and unplowed ground. Ahead of the moldboard plow, the disc harrow is a valuable tool to cut up and free tough sod. When employed in tandem with spring tooth harrows, a great deal of work can be accomplished in much less time. Originally offered as a pamphlet to new owners of the implement, we offer this reprint unabridged because it may be helpful to someone struggling to make an old gang disc usable. SFJ
INSTRUCTIONS FOR SETTING UP
- Remove all wires and arrange parts conveniently.
- Oil all bearings and moving parts as you proceed and see that they work freely.
- Bolts must be used in the holes in which they are found, or in parts to which they are attached, unless otherwise shown.
- Shaded portions in the illustrations show parts to be assembled. These must be placed on the machine in the order numbered.
- In the following instructions, wherever the terms “left” and “right” are used, it should be understood to mean from a position behind and facing the machine.
(See Illustration No. 1)
- Attach front harrow frame to gangs with bolts located in bearings. Tighten nuts securely and spread cotters.
- Bolt draft angles, assembled with gang adjusting screw adjusting screw and set levers, to frame and cross bar as illustrated. Note: The gang adjusting screw bearing is furnished assembled in lower holes in adjusting screw standards. This bearing may be moved to upper holes, if more convenient for the operator (See “A”, Illustration No. 1.)
- Secure lower end of adjusting screw standard braces to frame angles. See that nuts on adjusting screw standard brace truss are tight.
- Slip set lever bars through slots in snubbing plate and secure to gang bearings with drilled bolts. Be sure bow in set lever bars is UP, exactly as illustrated. Attach set lever bars to set levers at the second (or inside) hole at front end of set lever bars for 5-ft. And 6-ft. Harrows, and at the end hole for 7-ft. And 8-ft Harrows. Tighten nuts securely and spread cotters.
- Secure inner and outer standard braces as shown.
- Attach scrapers to rear weight box angles as illustrated. The reinforcement plates go inside the weight box angle.
(See Illustration No. 2)
- Attach rear harrow frame to gangs with bolts located in bearings. Tighten nuts securely and spread cotters.
- Secure outer standard braces as illustrated.
- Attach outer draw bars, right and left, to inner gang bearings with bolts located in bearings. Attach draw bars to standards and weight box-angles as shown. Tighten nuts securely and spread cotters.
- Pass inner draw bars between swivel plates and straps and secure with drilled bolt, nut and cotter. Note: To obtain more or less angle to the rear gangs than the front, the bolt may be moved to the rear or front hole as required by the operator.
- Move front harrow into positions and attach rear harrow to front by means of bolts through connection eyes and weight box angles.
- Attach outer draw bar pressure brackets as shown. The cutting depth of the inner end of rear gangs may be controlled by raising or lowering the brackets.
- Attach scrapers to rear weight box angles as illustrated.
Power Gang Angling Attachment (Special)
This attachment is furnished in a complete unit and can be connected to the harrow by removing the draft angles and connections of the crank angling mechanism, and bolting the power angling attachment to front harrow frame and cross bar as shown in illustration. The set lever should be attached to set lever bars at the second (or inside) hole at the front end of set lever bars for 5 and 6 ft. Harrows, and at the end hole for 7 and 8 ft. Harrows. If necessary, readjust snubbing plate so that the gangs are held at the required working level.
To angle the gangs, pull the adjusting rope and move tractor ahead until the desired working angle is obtained. To straighten the gangs, back the tractor.
Rocking Scrapers (Special)
- Attach scrapers to rear weight box angles by means of bolts through scraper bar hanger. The reinforcement plate goes inside the angle (See “6”, Illustration No. 1.) The straight end of the scraper spring rests on the weight box angle. Hook the scraper spring in spring holder.
- Attach scraper lever and stop as illustrated. Set lock nuts on the stop so that the scraper blades come to the extreme edge of the disks when the scraper is rocked.
- Adjust scraper blades to just clear the disks when at center, by using the clamp near the scraper bar hanger. Fasten ropes as shown.
Full Blade Scrapers (Special)
Attach scraper bar, complete with scrapers, to rear weight box angles with bolts and space pipes. The space pipes go between the two angles.
Scrapers should be set (by means of bolts and slotted holes in scraper bar) to just clear the disk blades.
Center Tooth Attachment (Special)
(For Rear Harrow Only)
Bolt Center Tooth Attachment securely to rear harrow frame and cross bar angles, midway between the inner draw bars, as illustrated.
Note: For harrows equipped with 16” disk blades, the center tooth support bracket (P24325) is bolted to the angles with the offset UP, as illustrated. For 18” disk blades, P24325 is turned over and bolted to the angles with the offset DOWN.
Remove the inner draw bar swivel pins and attach the hitch to the tractor disk rear harrow by using the drilled bolts furnished with the hitch. Use the holes at the front end of the hitch angles that more nearly equal the distance between the inner draw bar swivel pin holes.
Adjust the hitch height by means of stop bolts and double nuts, the angles being held between the two nuts.
INSTRUCTION FOR ADJUSTING AND OPERATING
Keep all moving parts well lubricated when the harrow is in use. Use the grease gun supplied with the tractor.
For best results, the draft angles (front frame) on the front harrow should be approximately level when the harrow is hitched to the tractor. If necessary, adjust tractor draw bar to obtain this result.
In practically all field work the gangs should run level and cut at an even depth. Adjust the front harrow gangs to suit by raising or lowering the pressure plate at center of front harrow frame.
The rear gangs may be leveled by raising or lowering the outer draw bar pressure plates. If the harrow ridges the soil between the rear gangs, the soil may be leveled by raising the inner end of the gangs, or by giving them less angle by moving the rear harrow frame forward at the three holes in the inner draw bars.
If the rear gangs do not fill a center depression left by the front harrow, reverse the above adjustment.
The adjustment at the outer ends of the rear harrow frame is for spacing the rear gangs closer or farther apart to meet field conditions, or for changing the trailing position of the rear harrow. The adjustment is carefully set and locked in place at the factory to meet average conditions. If any change is necessary move both gangs outward.
For all field work the upper collar on the gang adjusting screw should be placed at the hole nearest the hand crank so that if the harrow is backed the gangs may straighten. With forward movement the gangs will again assume angle. (The lower hold, next to the crank bearing, is intended only for demonstration purposes.)