92 / 07.06.2022


Perkins engines are one of the most used in the industry of agricultural machines and construction machines. They are known for being very reliable, durable and providing plenty of power to get any job done.

After many years of use, any engine can begin to present mechanical failures related to the wear of some of its parts, although each part of a Perkins engine can be replaced, basic knowledge in automotive mechanics is required to carry out these procedures.

At Maq Parts we have an extensive assortment of all the spare parts and spare parts that your Perkins engine may need. In this post we will explain step by step how to disassemble it and how to check each of the parts of a Perkins engine.


We strongly recommend that dismantling and repairing a Perkins engine should only be carried out if you have the tools and experience to do so. Remember that an engine is a very complex machine, each part must be carefully removed and put back in exactly the same order it was removed.

If during the disassembly of your Perkins engine you do not have any of the necessary tools to do so or you do not consider you have the basic knowledge of automotive mechanics to carry out the procedures, we strongly recommend that you go to your trusted mechanic so that you do not commit a mistake. mistake that could break any of the parts or damage the operation of your engine.


To carry out all the procedures without inconvenience, you will need to have the following tools at hand:

  • Screwdrivers set
  • Ratchet wrench set
  • Heavy duty cable or C-clamps
  • Rubber mallet or medium hammer
  • Lock pliers
  • Pliers
  • Sphere Alexometer
  • 5 Fine pin
  • Wire cutters
  • Voltmeter or multimeter
  • Ball hammer
  • Lever bar
  • Feeler gauge
  • Valve puller
  • Micrometer
  • Car ramps
  • Hydraulic jack


If you already have all the tools mentioned in the previous section, now we can get started:

Step 1: Lower the engine of the machine, once we have lowered it, turn it over so that its position is inverted.

Step 2: Subsequently, with screwdrivers, you have to remove all the screws that hold the engine cover and then remove it.

Step 3: After removing the crankcase cover, the first thing you see is the engine oil pump with the oil filter protruding, this is distinguished by having a metal mesh shape that is responsible for preventing impurities from entering that can damage the pump.

Step 4: The first piece that we can extract is the oil pump, to do so we must loosen the "bolts" or bolts that hold it with the help of a set of dice.

Step 5: Once we extract the oil pump we can see the connecting rod caps, depending on the position of the engine you will notice that they are in pairs, in the case of 4-cylinder engines, connecting rod 1 will be in the same position than 4 and 2 in the same position as 3. For 6 cylinder engines Connecting Rod 1 will be in the same position as 6, 2 in the same position as 5 and 3 in the same position as 4.

Remember, each connecting rod must be placed in exactly the same position, if they do not have factory numbers, mark them to identify them.

Step 6: Next, with a rattles, loosen the connecting rod caps. Once the connecting rods are loose, gently hit them with a rubber hammer to release them and be able to remove them.

Step 7: As we mentioned in step 5, the connecting rods are in pairs, when you finish extracting the first 2 you will have to turn the crankshaft a little so that the other two that were hidden are above and you will proceed to repeat step 6 with the following 2 connecting rods.

Step 8: Once we have removed all the caps, hit the connecting rods from behind with the rubber mallet, slowly pushing the piston inside the cylinder until the ring, piston and connecting rod come out completely.

Step 9: Once we have removed all the connecting rods from the engine we proceed to do a general cleaning of the engine block, for this you will need special cleaning products for engines and thus be able to remove the oil, carbon, among others.

Step 10: When the engine connecting rods have been removed we can proceed to remove the pistons one by one, try to remove them from the same side where the connecting rods were removed.

STEP 11, USE OF THE ALEXOMETER: After each one of the pistons has been removed, it is recommended to perform a probe of the internal diameter of the cylinders with an Alexometer.

The objective of this step is to measure the wear in the cylinders of the engine, considering that the bang that occur during combustion gradually wear out the cylinders, due to this a small step is created between the upper area of the cylinders.

This procedure consists of measuring the step to know the wear of the motor, the deeper or more pronounced the step, the more wear the motor will have.

1. We choose the correct extension piece for the cylinder diameter of our engine. This diameter will be found on the manufacturer's sheet. You must consider that the diameter of the part you choose must have a total length of the head (including the maximum tolerance) slightly greater than the nominal diameter described in the motor manufacturer's sheet, this will guarantee that the tracers are in permanent contact with the cylinder walls.
2. Place the alesometer perpendicular to the cylinder and adjust the clamp or fixing nut to the cylinder walls.
3. Measure with a micrometer the normal diameter of the cylinder.
4. Insert the head of the alesometer into the cylinder and calibrate the dial gauge to zero by gently moving the alesometer in an oscillating manner until we obtain a minimum measurement that we will take as a reference. In that minimum measurement we will calibrate the zero.
5. Remove the alesometer from the micrometer and insert it into the first cylinder to be measured. Make sure that the bore gauge enters the cylinder in an inclined position, as this will not damage the feelers.
6. Once inside the cylinder, we align the handle of the alesometer with the axis of the cylinder and take the reading of the dial gauge.
7. Once again, we continue to move the alesometer in an oscillating manner until we find an inflection point that is the exact point of measurement. If that point coincides with the prefixed zero on the scale, the measure we are comparing will coincide exactly. If, on the other hand, the inflection point coincided, for example, with 5 on the scale, the compared measurement would be 0.05 mm more than the preset measurement.
8. To extract the flexometer from the cylinder, we must again do it with the body tilted to avoid damaging the dial indicator.

Step 12: Once we have the diameter of each of the cylinders of your engine, it must be compared with the original diameter, this can be found in the data of the manufacturer of the Perkins engine that you have.

Considers that, to obtain reliable results, it is necessary to make a sufficient number of measurements. It is recommended to carry out at least three measurements at three different heights (nine in total for each cylinder) this will give an excellent approximation of the state of wear of the measured cylinder.


Depending on the results obtained compared with the manufacturer's data, it will be possible to determine if the engine wear can be solved with a rectification or if it is necessary to change the rings.

In case of rectification, it will be necessary to take the cylinders to a rectification workshop where specialized engine machines will carry out the necessary processes to correct the wear on the cylinders.

If the wear damage is more serious, rectification will not be enough and the piston rings will have to be changed to recover the original diameter and avoid excessive fuel consumption.

When you have carried out all these procedures we can choose between two routes, take the engine to the rectifying workshop to carry out major maintenance or change the cylinder rings and reassemble the engine by placing the parts in the same order in which they were removed.

Remember that in both cases the engine must go through a special cleaning in which all the shavings, earth, grease or dirt that could remain inside the cylinders will be dislodged, if this is not removed it can harm the operation of the engine.

Finally, if you want to know what is done in a refinish workshop, we invite you to continue reading the second part of this post about Perkins engine maintenance.

Find all the necessary parts for the Perkins engine

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