How to remove the gear from a chainsaw

How to remove the gear on a chainsaw

Chainsaws made by well-known manufacturers of special tools are characterized by the highest reliability and long life. This is due to their ingenious construction and the use of special grades of tool steel from which all moving and rubbing parts are made. These should include first:

• the chain with the cutting edges;
• guide bar;
• The chain sprocket, which is driven in a rotary motion by the energy of a single-cylinder two-cycle internal combustion engine.

They all work in saturation mode and over time they wear out. even small variations in the geometry of these parts can worsen the performance and smoothness of your saw. If you needed to remove a sprocket from a chainsaw to replace it, you need to understand the mechanism of the clutch system, with which it has a specific connection.

Types of drive sprockets

There are two kinds of drums, depending on the purpose of the chainsaw, professional and consumer. the frequency of sprocket changes depends on it: if a home saw is used much less often than a professional saw, it will also require fewer replacement parts like sprocket, bearings or pinion.

By design, drive sprockets come in two types:

Solid or non-disassembly type. As the name implies, it is a single piece of construction where the clutch plate and the sprocket are permanently welded or pressed together. If necessary, the entire part is replaced.

To the left of the clutch drum (aka sprocket) is a needle bearing.

The replacement ring is located on the right side of the clutch drum.

Once you have determined the type of your saw and the sprocket to be replaced, you can begin the process of updating the mechanism.

Sprocket replacement

Before replacing, you need to prepare, gather the necessary tools, buy the parts you plan to replace.

When you buy a new sprocket, look for the model and brand of your chainsaw, not the size of the part, otherwise the part might not fit!

Needed Tools

• Quality saws from reputable manufacturers come with a special wrench for removing the sprocket. Unfortunately, cheaper tools do not have such a wrench.
• Sprocket wrench.
• For saw models not equipped with their own key, a copper or aluminum chisel is used.
• Hammer (for unscrewing the sprocket with a punch).
• Flat screwdriver.
• Bearing grease.

When all necessary tools are prepared you can start replacing the part. It is worth noting that there are peculiarities in the replacement of the sprocket on saws from different manufacturers.

Step-by-step replacement algorithm for any chainsaw

At this stage of tool maintenance, the non-disassembled device can be replaced with a prefabricated mechanism. This will simplify the process of replacing the sprocket in future operation.

From here all the steps are repeated in reverse order to reassemble the chain saw. In case you service the product of demountable type, you change only sprocket, without the drum, the process is otherwise identical.

Now let’s look at algorithms of sprocket replacement on different models of saws.

Replacement on the ECHO saw (Echo CS-3500)

• First remove the saw headset: Use the included Allen wrench to remove the bar nuts and covers.
• Remove the bar and then the chain.
• Remove the air filter cover.
• Remove the candle.
• Fix the piston in the cylinder with a stopper instead of the removed spark plug.
• Included with the saw should be a puller, which should be installed in a universal wrench. Use it to unscrew the clutch and remove it.
• Replace the drum or chainring and check the cage.
• Reassemble in the reverse order.

Replacement on your Partner 350 Saw

• Open the side cover to access the sprocket and tire.
• Remove the bar and loosen the chain.
• To access the piston unscrew the spark plug with a socket wrench.
• Rotate the sprocket until the piston is almost at the top, stop it and secure it with a rope.
• Use the wrench that comes with the tool to remove the reel.
• Replace necessary parts and Reverse order to reassemble saw.

Replacement on the STIHL 180

On a German chainsaw, the process of removing the drive sprocket is very simple and consists of the following steps:

• Remove the tire guard.
• Remove guide bar and saw chain.
• Remove the retaining ring.
• Remove the lock washer.
• Remove the drive sprocket.
• Remove the needle bearing for lubrication.
• Replace with new parts.
• Reassembly.

Before you put these algorithms to the test, make sure you really need to replace the sprocket.

Most Chinese chain saws have a clutch design similar to the Husqvarna, so it’s rare to find a drive sprocket like the one on the Stihl. The above described procedure is applicable to most STIHL chain saws, especially domestic and semi-professional chainsaws.

In the photo you can see next to the saw: the drum, the bearing, the circlip, the washer and the clutch on the saw itself.

Clutch repair: The nuances of the process

When servicing clutches yourself, you need to know that:

• Several saws have a washer between the sprocket and clutch, and the sprocket and motor. Take this into account when carrying out repairs;
• the special spring of oil pump actuator must not be damaged during disassembling and must be returned to its original position. Otherwise, the chain will be dry or not lubricated at all.

A tool that has been repaired should be checked to make sure the bolt ties are secure, the chain is lubricated, and the motor is in good working order (it should engage smoothly and run smoothly). Only then may it be operated.

Fuel supply

In addition to the above-mentioned clogged breather, there may be other problems with the fuel supply. The main obstacles can be:

Fuel filter clogging. To check the unit for this malfunction, you need to disconnect the fuel hose and see how the fuel flows. If the jet is weak, you may need to clean the filter. The filter device is taken out through the filler hole of the tank and cleaned, if the contamination is too severe, it is replaced.

Professionals recommend changing the filter every few months, regardless of contamination.

Shortage of fuel. In this case, several factors may be the problem. The first is a dirty air filter. The problem is that not enough air is delivered to the carburetor, resulting in poor engine performance. The filter must be removed, cleaned, rinsed and dried, then adjusted again.

The second cause is an unadjusted carburetor. Her, t. е. Adjustment is done with three screws.

And the last cause is a problem with the monolithic membrane or contamination of the carburetor ducts. As in other cases, it is essential that the components be dry and clean.

• The saw headset is removed first, a universal wrench is used to unscrew the nuts on the bar cover. The cover is removed and the bar and chain are removed.
• The air filter is removed.
• Unscrew the spark plug by means of a universal wrench. A piston stopper is temporarily put in its place, which allows the piston to be locked in the cylinder.
• Install the puller in the socket on the universal key. After that, you can freely unscrew the clutch clutch. All actions are performed in clockwise direction.
• Remove the clutch clutch to make it easier to access the internal parts. Then the sprocket (clutch drum) is removed.
• On the basis of what kind of drum is installed in the machine, inspect it and check the crown. Replace the sprocket or rim with a new part. When replacing them, always check the condition of the clutch in the cage. the springs in the centrifugal mechanism and the cams must be checked particularly carefully. If they are found to be badly worn, these parts must also be replaced.
• If the condition of these elements is satisfactory, the assembly of all parts of the chainsaw is carried out in reverse order. Initially it is necessary to unscrew the piston stop, pull out the starter cord, and re-screw the stop. Thanks to such complex actions, it is possible to perform the clamping of the centrifugal mechanism on the crankshaft.
• Using a universal standard wrench, it is necessary to make the clutch clamping counterclockwise.
• After these steps you can continue to screw the other parts in their original places.

In order to correctly and without defects replace the sprocket on a chainsaw, it is necessary to perform all the work in a quality and accurate manner. If you do not have special tools for repair work, the process of replacing the drum may fail, because there is a chance of breaking not only the star or centrifugal mechanism, but also the saw chain.

The information above gives you a good idea of how to remove the chainwheel from your chain saw. Thanks to this there should be no difficulties at all and the task can be successfully performed absolutely independently. Once you have done it, you will have no problem doing it again when you need to. For a clearer understanding of this procedure, we recommend watching the video on disassembling a chainsaw and removing the sprocket.

The main reasons for replacing the drive sprocket

A universal spanner is the basic tool for replacing the sprocket.

The most common reasons that force a tool repair related to the replacement of the drive sprocket are:

• Chain jamming due to defects in the machine’s operation;
• high sprocket wear due to prolonged use of the machine.

Regular use of the attachment causes increased wear on the drive sprocket as a result of the increased loads placed on it when sawing wood. There are two ways of operating the unit:

In the first type of operation, the chain is operated until it is completely worn out. This method has several disadvantages. The main disadvantage is the problem of checking the wear during intensive machine operation.

If two or more chains are used in the process, the wear on the chain and sprocket will be evenly distributed so that the unit will operate for a longer period of time before the repair consisting of replacing the sprocket. In addition to sprocket wear, the bearing in the sprocket should not be forgotten. This component works at all engine speeds. If the sprocket is replaced, the bearing has to be replaced at the same time.

The clutch and sprocket must be replaced on time. At untimely carrying out of repair work in the course of functioning of the tool the increased vibration which leads to increase in wear of bearings established in an internal combustion engine on crankshaft half-axes arises. Sprocket tooth wear limit is 0.5 mm or less. Sprocket life is twice as long as a single chain, so you should use two chains while working. After service life of chains is over it is necessary to change chains and a leading sprocket at the same time.

Design and operation of the drive sprocket

The quality of maintenance of the tool, depends largely on understanding of its components, so to complete the picture, we will give a brief overview of the types and features of existing transmission elements. The chainsaw drive pinion, which is located on the clutch plate and is set in motion when the engine speed increases. These elements may be of all-metal or collapsible construction. The first option calls for a complete replacement when worn, but in the case of the latter, it is sufficient to replace the detachable ring gear.

The sprocket size limits their use for all chain types. There are two common standards: 0 pitch.325 mm and 3/8″ (the most important parameter when choosing for replacement). This standardization is based on the power capabilities of the chainsaw engine. In addition to the sprocket pitch, the choice should be based on the number of teeth (6 or 7) and the internal diameter of the bowl, but it is best to start with the specific model you have.

How to remove the clutch on a chainsaw

The chainsaw clutch drum, aka the drive sprocket, is a consumable item and therefore requires periodic replacement. The main reason for replacement: wear of the sprocket teeth by the saw chain. If the drum is solid, the chain will cut through the sprocket when in continuous use and the whole drum must be replaced. On some chainsaws, the clutch drum has a replaceable ring that also wears out. In this case, only the gear rim is replaced; the drum, if in good condition, is left for future use.

Many chainsaw owners don’t think twice about how to remove the clutch on a chainsaw themselves, because they have the option of going to a service. But such an opportunity is not for everyone, so we publish this article, which will explain step by step how to remove the chain saw sprocket.

This operation is not complicated at all, if you have the necessary tools and parts at hand. In this article, as an example, all actions are made with a chainsaw Echo CS-3500, all operations to replace the clutch drum for other chainsaws are similar.

Changing the chain saw drive sprocket is a simple procedure that you can do yourself without calling a service center. Contact our store, and you can serve equipment ECHO your own hands.