Usage:
120G, 130G, 140G, 12G, 14G, 16G Motor Graders
Description of Change: New steering cylinders are used on Series "G" motor graders, and two new relief valves are used in place of the former single relief valve. Also, new socket groups are used with the steering cylinders on all except the 16G Motor Grader. With the new cylinders, a different procedure is used for adjustment during assembly. See the topic "Assembly Adjustment".
The new sockets have a longer thread length for better linkage adjustment, and the new cylinders have a longer stroke. With the new adjustment and longer stroke, movement of the steering linkage is now limited by mechanical stops instead of piston contact in the cylinder. At the limit of steering travel (movement), a stop on the spindle housing makes contact with a pad on the axle yoke. This prevents stress in the steering cylinder and socket.
The two new relief valves in the system have more flow capacity than the single valve formerly used. This will give better protection of the steering cylinders and sockets from impact stresses.
Adaptable To: All earlier machines when the new parts are used together. To install the new relief valves, the mounting bosses on the motor grader frame must be changed.
If desired, a modification can be made to earlier motor graders which will have a similar effect without installation of the new components. A .375" (9.53 mm) thick steel block can be added to the present stop on each spindle housing. This will make contact before the cylinders are at the limit of their stroke, and prevent stress in the cylinders and sockets. Grind the stop surfaces if necessary to give maximum contact area. The addition of this mechanical stop will cause a reduction of approximately 4° in the maximum steering angle.
ASSEMBLY PROCEDURE: To adjust the front axle steering cylinders, lift the front wheels off the ground and put blocks under the axle for safety. Then follow this procedure:
1. Adjust the tie rod to give the correct wheel toe-in (alignment), and fasten the leaning wheel tie bar in the lock position.
2. Install the sockets into the steering cylinder rods as far as they will go, and install the tapered stud of each socket in the spindle housing arm.
3. Turn the steering wheel to move the front wheels to a position of maximum left turn, and hold the steering wheel in this position.
NOTE: During the next step, it will be necessary to turn the steering wheel back enough to release hydraulic pressure, but be sure the steering system is turned to the maximum when adjustment checks are made.
4. Turn the right hand cylinder rod to extend the socket until the stop on the left spindle housing is in contact with the left hand stop on the axle (grind the stop surfaces if necessary to give maximum contact area), then turn the cylinder rod six more complete turns and tighten the lock nut.
5. Turn the steering wheel to move the front wheels to a position of maximum right turn, and hold the steering wheel in this position.
NOTE: During the next step, it will be necessary to turn the steering wheel back enough to release hydraulic pressure, but be sure the steering system is turned to the maximum when adjustment checks are made.
6. Turn the left hand cylinder rod to extend the socket until the stop on the right spindle housing is in contact with the right hand stop on the axle (grind the stop surfaces if necessary to give maximum contact area), then turn the cylinder rod six more complete turns and tighten the lock nut.