Have you often thought about changing the chain on your bicycle? And in general, how do you know when it’s time to change the chain? How to check chain wear? What's wrong with a worn chain? Today we will try to give comprehensive answers to these questions!

Circuit device

To understand what, how and why, you must first understand how the circuit works. Here is a photo of an ordinary “ Gaal's chains"or as it is now commonly called " Roller chain »

1. Outer plate; 2. Inner plate; 3. Pin; 4. Bushing; 5. Roller.

Bicycle chains do not have element number 4.

Where does chain wear occur?

Contrary to popular belief the chain does not stretch over time. Wear occurs on the pins that connect the outer and inner links. The standard distance between two adjacent pins is 12.7mm. Over time, they develop and this distance increases. This increases the length of the chain, rather than stretching the outer and inner plates.

Why change a worn chain?

A worn chain has a detrimental effect on shifting and also causes faster wear on other transmission components..

Sprocket wear occurs due to the fact that a new, unworn chain sits tightly on the sprocket, and the roller sits tightly on the chain pin. With the appearance of wear, the pin begins to “roll” in the roller and “roll out” the distance between two adjacent teeth of the star. To understand this more easily, just look at the schematic diagram below. Green represents the roller, black represents the pin, and orange represents the star:

Also, due to the gaps between the pin and the roller, dirt accumulates faster and more in a worn chain. And dirt acts as an abrasive, further increasing wear on the chain and transmission components and impairing shifting. Therefore, if you put an old chain on new sprockets, it will kill them very quickly.

How to measure wear

Special wear gauge

There are many modern chain length meters from all sorts of famous brands. The essence of all meters is simple - to measure the distance between several links of the chain and, thereby, determine whether it is worth changing the chain. The cost of such meters varies from 500 rubles to several thousand rubles.

We recommend the option with a caliper. It’s simple, quick, and you or your relatives probably have a caliper made during the USSR lying around somewhere. Moreover, it is not difficult to buy it for little money at the nearest flea market. The accuracy of his measurements has hardly decreased since that time, and it is a very useful thing in the household.

The method of measuring with a caliper is simple. We take a caliper, spread it out to 119mm and insert it into the chain links so as to measure the distance between them. If the caliper shows values ​​from 120.6 to 120.9 mm, then the chain can already be changed. If the value is more than 120.9 mm, then in addition to the chain, you will also have to change the sprockets and cassette.

How often to change the chain

Often the chain is not that expensive compared to the rest of the transmission. And for one set of transmission you can change 2-3 chains. Therefore, in the long term, a timely replaced chain significantly extends the life of other components. On average, manufacturers recommend changing the chain every 1,500 km, but it all depends on your pedaling style, frequency and quality of chain lubrication. Monitor the wear periodically and replace the chain until it begins to wear out the transmission.

Bottom line

Monitoring the condition of the chain is not so difficult, and the money saved in the future will more than offset both the time spent on measurement and the financial costs of a caliper. And if you also start using paraffin lubricants, which are being tested, the savings will be simply enormous.

Welcome!
From time to time, the chain of the “Gas Distribution Mechanism” wears out and as a result it requires replacement. Another very pleasing fact is that the timing chain can last a very long life, unlike the gas timing belt. To be honest, there were even cases when a car drove about “180-200 thousand km” with the timing chain never changed, but it was really already very stretched at that time and the guarantee that the chain would soon break was very high. How many kilometers have you driven the most on just one timing chain?

Summary:

How much will a replacement cost? timing chains?
1) Replacing the timing chain will cost you around 250-500 rubles.

When should the timing chain be replaced?
The timing chain must be replaced if:

• Its stretching, namely when the standard chain tensioner is no longer able to tension the chain.
• It also needs to be changed when the car has covered about 80-100 thousand km. (It may take longer to go here; the most important thing is to look at its stretching; if the stretching of the chain is very large, then in this case it is better to replace it, otherwise it will simply break)

What is needed to replace the timing chain?
1) Bricks.
2) Hammer.
3) Screwdrivers.
4) Wrenches.
5) You may need a mounting blade.
6) A hook, or anything else that can be used to hook the chain.
7) A key for unscrewing the crankshaft. (If not, then a 36 head will do!)

How to replace the timing chain on a VAZ 2101-VAZ 2107?

Removal:
1) First, remove the cylinder head cover. (On how to remove the cylinder head cover, paragraph “1-10”)

2) Now turn the crank until the mark on the camshaft sprocket aligns with the mark on the housing.

Note!
Label on crankshaft, will also have to match the mark on the camshaft cover!

4) Then engage fourth gear and put the car on the handbrake.

5) Next, loosen the camshaft sprocket bolt.

6) Then remove the chain guide from the engine. (For information on how to remove the chain damper, read “in this article”)

7) Then remove the chain tensioner shoe from the engine. (For information on how to remove the chain tensioner shoe, read “”)

8) Next, bend back the lock washer, which is located on the bolt securing the sprocket of the auxiliary units.

9) Now unscrew the bolt itself that secures the accessory sprocket.

10) Then remove the accessory sprocket.

Note!
After removing the sprocket, do not turn the drive shaft, because this may disrupt the initial ignition setting! (see photo at the very bottom of the article, in the “”)

12) Next, completely unscrew the bolt that secures the camshaft sprocket.

13) Then lift the chain and remove the camshaft sprocket.

14) Then lower the chain deeply down, carefully removing it from all the sprockets.

Note!
To remove the timing chain, you do not need to remove the crankshaft sprocket!

15) After all the operations performed, check whether the mark on the crankshaft sprocket matches the mark on the cylinder block.

Note!
If the marks do not match, check crankshaft before combining them!

Installation:
1) First put a new chain on the crankshaft sprocket.

2) Then put the chain on the sprocket of the auxiliary units.

4) Next, hook the chain.

5) And then lift the chain up to the installation location of the camshaft sprocket.

6) Then put the chain on the camshaft sprocket, and only then install the sprocket in place.

7) Next, check that all marks match and tighten the timing chain. (How to check the coincidence of the marks, see the article: “Installing the piston of the fourth cylinder at TDC - Top Dead Center”) (And about how to tension the chain, read “in this article”)

Note!
If you do not understand how to tension the chain, then at the very bottom, watch the video on correct installation chain and its tension!

8) Then tighten the camshaft sprocket bolt.

9) Then install the chain guide in place in the reverse order of removing it.

10) Then again install the chain tensioner shoe in reverse order.

11) Next, install the stop pin in place.

12) Now put the gear in neutral and turn the crankshaft three turns in the direction of its rotation.

13) Check that all marks on the sprockets match.

Note!
If the marks do not match, install the chain again and correct the situation!

14) If all the marks match then:
1. Tighten the chain tensioner cap nut.
2. Shift into gear.
3. Tighten all sprocket bolts.
4. Install all remaining parts in the reverse order of removal.

Important!
1) When working in a ditch, place bricks under the wheels of the car to prevent the car from rolling away!
2) If you are unable to remove the auxiliary units sprocket, then try moving it using a mounting blade and then remove the sprocket!

For newbies!
Question: Where is the accessory drive shaft located?
Answer:

Additional video:
If you don’t understand how to install a chain on a car, then watch a short video that explains everything in detail with the engine removed from the car.

The car owner periodically encounters breakdowns. Some can be eliminated quickly, while others will require some fiddling. The problem we will talk about today falls into the second category. Changing a timing chain requires serious technical skills. But this does not mean at all that self-replacement impossible.

Reasons for replacing the timing chain

It must be replaced in two cases:

1. In case of a break.
2. In case of serious sprain.

A broken circuit is an emergency. If this happens while driving, all the valves in the engine are almost guaranteed to be damaged. They will have to be changed along with the chain, and replacement (with preliminary grinding) will require the intervention of specialists and will be very expensive for the car owner.

Chain stretching is much more common. As a rule, it is associated with so-called metal fatigue. Typically, the chain stretches slightly after 200-300 thousand kilometers (but this only applies to original, high-quality chains from the car manufacturer; lower-quality chains can stretch after 80-100 thousand kilometers). Stretching leads to disruption of the coherence in the operation of the camshaft and crankshaft, which in turn affects the operation of the entire engine. It becomes unstable, at low speeds the engine loses throttle response, jerking appears when starting, etc.

How to determine wear

• most reliable way - computer diagnostics. The car is sent to a car service center, installed on a special stand, and the program accurately determines the degree of desynchronization between the crankshaft and camshaft, after which the car owner receives a graph of the torques of these shafts, for clarity. This method is especially relevant for those who purchase a car second-hand. It's no secret that unscrupulous sellers often cheat the mileage meters on cars, assuring buyers that the car has traveled very little. Their motives are clear: reducing mileage is much easier than changing a stretched part;
• second sign of wear: error P0355 is constantly lit on the control panel. The instructions say that it appears when the crankshaft sensor is faulty. But in practice, this may mean that an unscrupulous seller changed this sensor (or even the entire control unit) before the sale in order to mask another error, but the stretched chain did not go away;
• third sign of wear: extended tensioner rod. To look at it, the car owner will have to remove the front engine cover. If the tensioner has moved 8–10 mm from its original position, the chain is stretched and needs to be replaced;

Choice: which spare part is better

There can only be one piece of advice here: you need to buy a spare part produced by the car manufacturer. And this should only be done in specialized service centers. Under no circumstances should you rely on third party products. Because this is a very important engine part, problems with which can lead to either very expensive repairs or complete failure of the engine. Yes, branded chains are expensive. However, this is not a part you should skimp on.

Timing chain replacement procedure

Before changing the chain, you should decide on the tools that will be needed for this.

Tools and Supplies

1. New chain from the car manufacturer.
2. Set of open-end wrenches.
3. Set of spanners.
4. Flat blade screwdriver.
5. Hammer.
6. Chisel.
7. Mounting blade.
8. A piece of wire (diameter 0.5 cm, length 30 cm).

Replacement sequence

1. The car is set to neutral gear. The front cover is removed from the machine engine to provide access to the shafts and gears.
2. The crankshaft is manually turned until the mark on the camshaft sprocket aligns with the mark on the engine housing. There is also a mark on the crankshaft itself. And it should also match the mark on the body.

   

   The marks installed on the camshaft and timing case must completely match

3. The lock washer installed under the camshaft sprocket bolt is carefully unbent using a chisel and hammer.

   

   The camshaft lock washer is unbent with a chisel and hammer.

4. Now the car is set to fourth speed, after which the handbrake is applied.
5. Use a spanner to loosen the camshaft sprocket mounting bolt.

   

   The nut on the camshaft is loosened with a 17 mm spanner.

6. After this, the timing chain guide is unscrewed and removed (it is most convenient to remove it using a wire hook):

   

   The chain guide is removed and removed using a wire hook

7. Next, the tensioner shoe is removed (it is indicated in the photo by number 1). To do this, use a 14-mm open-end wrench to completely unscrew bolt 2, after which the shoe together with the tensioner is removed from the engine:

   

   The tensioner shoe is indicated in the photo by number 1, the bolt that holds it is indicated by number 2

8. Now the sprocket of the auxiliary units is unscrewed with a spanner, but not completely. It weakens slightly, but remains on its shaft.

   

   The auxiliary sprocket is loosened, but not removed

9. Since the chain tension has weakened, it is hooked by a wire hook and removed from the engine:

   

   The old timing chain is removed using a wire hook

10. The new part is put on the previously removed camshaft sprocket. And only after this the asterisk is installed in place:

    

    The new chain is placed on the camshaft sprocket, which is then installed in the engine.

11. After this, it is checked whether the marks on the sprockets and shafts match; if not, the neutral gear is engaged and the crankshaft is manually turned until it matches. After which the bolt on the camshaft sprocket is tightened (but in no case tightened).
12. Now the chain guide and tensioner shoe are installed in their regular place.
13. Next, the nuts on the sprockets of the two shafts are tightened, after which the crankshaft is turned 3-4 times. At the same time, the coincidence of the marks on the sprockets and the body is monitored. If there are no discrepancies, the new spare part is generously lubricated motor oil, after which the front engine cover is installed in its original place.

Video: DIY chain installation

Replacing a timing chain is a complex process. Even for experienced craftsmen, it takes about 5 hours. A car owner who decides to carry out this procedure on his own must clearly understand what he is doing, since the consequences of incorrect repairs can be very serious. Particular attention should be paid to the correct location of the marks. It is necessary to achieve a perfect match and perfect synchronicity, since without this the replacement cannot be considered successful.

The engine timing chain is also “infinite”, “problem-free”, “armor-piercing” - there are thousands of epithets to justify it and all are only positive. Of course, any car salesman will tell you - yes, there’s a chain right there, which means you don’t have to worry about replacements after 100 - 120,000 kilometers, you bought it and what they say - forget it! But is this really so, is it really unwearable, and in the end, what kind of resource does it have? Let's find out...

Needless to say, a chain is definitely better than a belt; in terms of reliability, it seems to have no competition. After all, all elements are made of metal, and as we know, it is much more reliable than rubber, plastic and fabric threads in a belt structure.

Why don't some manufacturers supply a chain?

Now, it seems, the question remains: why do some manufacturers not install them, but make belts? It's not practical, is it?

There are several answers:

• It's noise. Whatever one may say, even a perfectly tuned engine with a chain is still noisier than with a belt. Well, try rolling metal and rubber links on asphalt yourself - you’ll understand which is noisier.

• Design feature. The fact is that some engines, for the sake of silence, cannot use a “metal counterpart”, because the belt drive is located outside the engine, that is, it rotates in the air. And so simply taking and fastening metal links will not work.
• There are beliefs that the belt better grips the gears of the shafts, both camshaft and crankshaft. After all, the gear really has wide strips for engagement, but the chain has teeth, and even in oil! No, of course, they also engage very effectively in the hook, and usually there are two rows of them. But as some manufacturers assure, they can jump over a tooth much faster than a belt.

• Well, and actually the last thing – tension. Tensioning a chain mechanism is more difficult than a belt mechanism. After all, the belt bends easily, and is again in the air. But the opponent is in oil inside, and it’s more difficult to tighten him - you can’t bend him as needed!

Some write that the chain mechanism is also more difficult to change, because in reality you need to disassemble almost half the engine, but for the belt drive, you unscrew the casing, remove it and quickly install another one! There is some truth in this, but in any case you will change the belt more often than the chain.

About engine maintenance

To begin with, I would like to say that the condition of the oil greatly affects the life of the chain. It is located inside, therefore, the better it is lubricated, the more the resource will increase. Also, indirectly, frequent replacement removes from the engine any debris such as sand, dirt, etc., which breaks and wears out the chain mechanism, because sand can penetrate anywhere, including into the connecting links. The new oil makes the pistons slide better, which relieves unnecessary stress on the chain mechanism.

In general, the result is this - to increase the service life, you just need to change the oil more often, at least every 1000 kilometers, but ahead of schedule. That is, the dealer claims 15,000 - change after 13 - 14,000, and ideally after 10,000, then the chain will last much longer.

Conventional engines

You know, I caught myself thinking that there is no information anywhere about how long to change the chain mechanism. That is, if you take a regular car, with a regular naturally aspirated engine (not a turbo - more on that below), the resource is often not limited by the manufacturer!

However, you can find the following information:

After a long mileage, about 150 - 200,000 kilometers, it is worth listening to the operation of the engine to see if there is excessive beating and noise. If it does, you need to diagnose the circuit and replace it if necessary.

That is, the main diagnosis is based on sound, and not after a certain mileage. Therefore, the resource varies from manufacturer to manufacturer, and from owner to owner.

However, if you crunch the numbers, you get:

Taking into account long maintenance (approximately 15,000 or more)

The chain lasts about 150 - 170,000 kilometers.

Taking into account short maintenance (approximately 10 – 13,000 km)

The chain can travel from 300 to 350,000 kilometers.

If you take care of your car, then the chain mechanism is really the last thing you change! But wait, my friend changed every 15 – 20,000, what’s the catch? YES in no way, it’s just that your friend has a VOLKSWAGEN engine, that is, a turbocharged one, and a weak one, with a volume of 1.2 - 1.4 liters.

Turbocharged engines

Completely different laws work here; turbocharged engines have much greater torque and effort, and therefore more horsepower!

Therefore, it is not surprising that the chain mechanism has a much shorter lifespan; the chain here simply stretches out. Then it jumps to a tooth - the engine does not work normally - it consumes a lot of fuel, starts to stall, does not pull, or does not start at all.

Moreover, it manifests itself on weak engines, such as 1.2 - 1.4 TSI. A design mistake was made there; the width of the metal was narrow.

Now think about the numbers that VAG pleased the owners with (though unofficially):

1.2 TSI engine - replacement after 30,000

Engine 1.4 TSI (122 hp) – 80,000

Engine 1.8 – 2.0 TSI – 120000

That is, to call such runs large is beyond words! However, just imagine how the timing belt would work in such conditions, would it even wear out after 10,000?

If we sum up the average figures for turbo engines:

The chain resource is about 120 - 150,000 kilometers. However, you need to read the maintenance regulations; some manufacturers have them strictly prescribed.

— at what mileage to check the condition of the timing chain,
- what are the verification methods?
- symptoms and signs of chain stretching,
— what will happen if you don’t change the chain on time,
— how to find out what tensioner is worth - new or old model,
- how much does it cost to replace a timing chain - OD and regular service,
— Is it true that you can ride up to 300 thousand without replacing the timing belt.

Checking the condition of the timing chain for 1.8 - 1.4 timing belts is carried out when the mileage reaches *60,000 km or 4 years of operation.
*by 60 thousand if the tensioner is an old model.
*by 80 thousand if the tensioner is of a new type.

The chain is replaced based on the condition of the tensioner.
As practice shows, this is usually at 90,000 km - maximum 120,000 km.
On my Skoda / 1.8 tsi / I checked it for the first time at 80 thousand.
As a result, the replacement took place for 100 kopecks.

You can check it programmatically -

So visually (only on 1.8 tsi) - on 1.4 engines there is no window.
This method is more reliable and shows the real condition.

Look at the number of grooves.

More than 6 - replacement. New sample.
More than 4 - old style.

Replacing the timing chain - at OD it costs from 40-45 thousand.
Regular service - 23 -28 rubles. /Moscow time/

SIGNS SYMPTOMS

A characteristic knocking sound when starting up under the hood in the engine area for about a couple of seconds.

When the timing mechanism is in critical condition, an indication appears on dashboard type CHECK ENGINE, the car engine stops working correctly, the following messages are recorded in the engine control unit: /info from Audi Club/

What happens if you don't replace it on time?

The answer to this question is quite simple: chain jump, damage to the block head. The degree of damage depends on many factors, for example, at what speed and what rpm it occurs and ranges from bending the valves to tearing off the valve head and destroying the cylinder block.

How to find out which tensioner is on your Skoda - old or new model

According to TPI 2025206/6, the new tensioner has been installed on cars since March 2012, starting with the engine number:

CAW_135390
CBF_106200
CCT_289558
CCZ_224768
CDA_307430

Myths about 300 thousand mileage, but the timing belt has never been changed

On the Internet you can find a lot of information with approximately the following content:

Operation: 90% highway;
Mileage: 300;
DSG works;
I did not change the chain;
or

370,000 chain is original, no one has climbed into the engine).

And now, I’ll write it as it is.
This screenshot, from many Shkodovods known not only on the drive, SUSLIKRUS.
As a master of our engines, he receives a decent amount of messages on the topic of engine repair.
One of which he posted on his blog.

Those in the know know: The timing belt is replaced with a 1.8 at 100-110 mileage.

Already at a mileage of 30-50 thousand, if you take care of the car, you need to monitor the condition of the chain, or rather, check the tensioner. Based on how many teeth have come out, you need to take measurements visually, and not programmatically.

No 300 thousand mileage, 350 - 400, etc. so that the timing belt has never been changed - this cannot happen!

P.S. A post for beginners and for those who have brains.

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