Motor graders are used for making smoother surfaces, fine grade and levelling the soil. They are even used for moving small amounts of dirt. Their most common use is in the construction and maintenance of roads with its main function being preparing the topmost layer for laying asphalt on top of it.

Structure

Typical motor grader models have three axles with the engine and cab situated above the rear axles at one end of the vehicle and a third axle at the front end of the vehicle with the blade in between.

Types

A small motor grader within a range of 80-150 horsepower is perfect for jobs that need to be completed in a tight spacing environment, while larger motor graders can be used in broader spaces. Self-propelled machines with an adjustable blade, motor graders are broadly classified into two categories i.e., Rigid Frame Motor Graders and Articulated Frame Motor Graders.

Inspection tips

Be it small or large motor graders or Rigid Frame or Articulated Frame Motor Graders, if you are planning to buy any one of the above used equipment, you need to ensure that you inspect the equipment properly. You need to carefully draft your inspection list and take a thorough look at all the motor grader components.

Here are some inspection tips for motor graders...

1. Check the frame of the motor grader thoroughly: You should always make it a point to take a walk around the motor grader carefully observing the frame of the machine. Through this way, you will be able to locate any fishplates which are generally metal reinforcements placed over or even behind a repaired crack. Make a note of it and do confirm with the seller if the repair was done by a qualified welder and when.

2. Pay attention to the motor grader’s circle: On the motor grader’s circle, moldboards are mounted and the angle and tilt of this moldboard can be manipulated by the equipment operator by manipulating the position or angle of the circle. It goes without saying that without a properly maintained and operating circle, the motor grader operator will not be able to carry out the fine grading tasks easily and it could become extremely difficult for him. Further, the circle’s surface should also be checked for any signs of uneven wear. If the circle is improperly aligned, then pinion gear teeth may see uneven wear and tear. Generally, uneven wear and the resulting vertical play do not happen through the use of shims. If shims are used, then start up the equipment and put the circle through its full range of motions so as to check for any play.

3. Have a thorough look at the moldboard: Inspect the moldboard and ensure that the cutting edge of it which is bolted along the bottom of moldboard and along the sides is always straight. There is no doubt that the rock and soil will lead to wearing down of the centre of the cutting edge which will eventually need to be replaced. Generally, it is seen that the cutting edge used to maintain rocky and unfinished roads do not last long. So, always ensure that the cutting edge is replaced at the right time and is in the right position. While buying the equipment, make it a point to see how much cutting edge is remaining on the moldboard. When the cutting edge is just half an inch or maybe less, then it should be replaced along with the bolts that are used for holding it in place. Always remember that it is better to replace the cutting edge than the moldboard as the later is very expensive and you would not want the moldboard to do the work of the cutting edge.

4. Look for any wear in the articulation point and linkage system: The scale of wear in the articulation point depends on the type of work performed by the motor graders. In case of rocky, rough and uneven ground, the wear is always more. Further, you need to ensure that the front and back half of the motor grader is in line and there is no difference in the level i.e., if the cab is sitting higher than the engine compartment or vice versa, this means that the articulation point is bent or loose. You need to ask the seller to repair this as soon as possible. Also, you should check the linkage system at the front of the equipment. This is because any strain and stress can be caused when tires are turned and leaned and this could damage the frame as well as the linkage system. Do pay heed to the inside of the frame and on the front axle for any evidence of damage. Check the steering component as well to ensure everything is upright.

5. All should be well with hydraulics, cylinders, lines and hoses: For checking the health of hydraulics correctly, look at the ground beneath the machine for any fluid leaks as you can easily spot it here. After checking under and around the equipment, observe all the cylinders, lines and hoses within the engine compartment, circle drive housing etc. Make a note if there is any leak or damage that will need to be checked.

6. Check for strange noise or incorrect behaviour of the brakes- Test the working of the brakes as sometimes the original ones are replaced by cheap quality ones. This may result in incorrect behaviour or strange noises, thus, hampering the work at jobsite. So, you need to start the machine and check the noise level. If the engine makes strange noise, then it means that the machine may not give good results.

Apart from the above mentioned inspection list, one also needs to look at the overall structure and exteriors of the equipment. For example, you need to pay attention to the tires and underneath and finally check the cab and other general operations of the motor grader. So, select the equipment with caution. Inspect carefully and compare different models before you make the purchase decision. Do remember the above mentioned tips.