How to change the timing belt on a Toyota Corolla with your own hands?

How to determine if a chain drive is faulty

Unlike the timing belt drive, which is located outside the engine, the chain with gears is located inside the power unit and is completely hidden from view. On the one hand, this is a plus: the mechanism makes less noise and is generously lubricated with engine oil, which increases its service life. On the other hand, without removing the valve cover it is impossible to visually assess the technical condition of the unit.

The first sign of a chain drive problem is a rumbling sound coming from under the cover when the power unit is operating. The rumble of a weakened chain cannot be confused with anything; it is heard from the side where the gas distribution mechanism is located.

Loosening with a gap of up to 1 cm allows the chain to jump when starting the engine

Having heard such a sound, the car owner should check the condition of the drive so as not to encounter big troubles associated with engine repair. There are 2 ways: immediately go for diagnostics to the nearest car service center, or remove the valve cover yourself and make sure that the section of the chain near the camshaft gear is loose. Worsening tension is caused by the following reasons:

• due to stretching to such a length that the tensioning device is unable to pick up the slack;
• due to a faulty tensioner;
• the damping plate is worn out or torn;
• Due to the high mileage of the car, all the parts of the mechanism have worn out - the chain, gears, tensioner and damper.

If an old-style mechanical tensioning device is installed in the car engine, then when the described symptoms appear, the first action is to tighten the chain with its help. To do this, simply loosen the outer nut holding the plunger spring and manually turn the crankshaft 1-2 turns. After which the nut is tightened again.

Old VAZ 2101–07 engines have a mechanical tensioner with a nut

Modern automatic hydraulic tensioners are not designed for manual adjustment and must be replaced if they break. You can verify that the element has failed only by removing it or disassembling the entire timing belt assembly. The same applies to the damper - on most cars, its wear can only be assessed when the mechanism is disassembled.

Ignoring the rumbling noise made by the chain will sooner or later lead to motor failure. The severity of the consequences depends only on your luck.

When is replacement required?

According to the maintenance regulations, the timing belt on a Toyota Corolla should be replaced every 60 - 70 thousand kilometers. However, in certain cases, this part may wear out and fail much earlier than expected. This may be due to overly aggressive driving style, the presence of a trailer, or even climatic conditions. Determining that there is something wrong with a part is quite difficult, since the signs of a gas distributor malfunction often coincide with the signs of other units and systems of the car.

A potential malfunction may be indicated by:

• Jerking of the car when driving;
• Dips in power when you sharply press the gas;
• Exhaust black;
• Problems with the starter;
• Knocking and strange noises in the engine.

If you detect at least one of these signs, you should immediately diagnose the vehicle systems, including the timing belt.

Its wear is indicated by:

• ruptures and cracks on its surface;
• worn or broken teeth;
• weak tension or sagging.

If the belt is worn out, it should be replaced urgently, otherwise it will lead to very serious consequences for the car. Its visual diagnostics should be carried out every 20 - 25 thousand kilometers.

Consequences of malfunctions

Problems in the timing chain drive lead to the following problems:

1. A stretched and weakened chain jumps several teeth. As a rule, this happens when the engine starts.
2. A chain operating with increased free play often breaks the guide and even “gnaws” a groove in the cylinder head made of aluminum alloy.
3. In some brands of cars where a single-row chain is used in power units, it may break.

Note. Chain drives of the timing unit can be single- or double-row. The former are not as reliable and durable as the latter, and often break down after a run of 50-80 thousand km. Double-row drives break extremely rarely, even when the owner of the car does not pay due attention to it.

Double-row chains also break, but very rarely

What is the service life of chains according to maintenance regulations and replacement frequency?

On average, a timing chain drive lasts from 200 to 350 thousand kilometers of a car. The indicator varies depending on the driver’s driving style and the quality of the engine oil used to lubricate the links and gears. The operation of the hydraulic tensioner also depends on it.

Reference. In cars from leading German and Japanese manufacturers, a double-row chain often lasts 450-500 thousand km, or even more.

Single row chain drive for Opel vehicles

In contrast to German brands, the two-row drives of Korean small cars from manufacturers KIA and Hyundai work surprisingly little. There have often been cases of stretching and replacing chains with a mileage of 60-90 thousand km on Hyundai Solaris (Hyundai Accent in Ukraine) and KIA Ceed models, which is comparable to the service life of timing belts. Hence the recommendations on when to replace the chain drive:

1. On Korean small cars, you need to listen and check the condition of the drive starting from 60 thousand km. If the outcome is good, replacement is carried out in the interval of 120-150 thousand km.
2. The same applies to single-row chains installed on many European economy-class cars, for example, Peugeot, Opel and small diesel engines from Audi.
3. Two-row transmissions of other car brands should be given attention after 150 thousand km, periodically checking their condition. Replacement is carried out as wear occurs, but on average - no earlier than 200 thousand km.

To avoid troubles associated with timing drive failures, you need to carefully study the car’s operating instructions and the manufacturer’s recommendations for servicing a particular car.

Signs of worn parts

There are several symptoms that determine whether the chain needs to be replaced:

1. It rattles when the engine is running.
2. It scrapes against the sides of the lid.
3. It looks like it's sagging a lot.

It is recommended not to skimp on this spare part and choose only the original one, because it affects the integrity of the engine and is changed once every 200 thousand kilometers. It’s better to spend five years’ money once and be sure that the engine valves will be in order.

The chain is much more reliable than the timing belt and lasts many times longer, but every coin has another side: changing it is much more difficult and expensive. For those who want to replace it themselves, detailed instructions are provided below.

How to choose a new set of spare parts

Like other automobile spare parts, timing chains are counterfeited by handicraft and Chinese manufacturers, after which they go on sale. Cunning businessmen are constantly coming up with new ways to deceive customers, for example, placing their low-quality products in original packaging from well-known brands originally from Western Europe. To avoid running into a fake spare part when purchasing a part, follow these recommendations:

• buy the chain from official sales representatives, dealers, or in stores that have a positive reputation among other users;
• do not try to save money by looking at products from unknown manufacturers;
• check the part for marks and deflection in a horizontal position;
• consult a familiar auto mechanic about which brand is best to choose for your car brand;
• Make a visual inspection of the product for careless workmanship or other signs - burrs, play between links, and so on.

The chain is checked for deflection as follows: take it by one end and hold it flat. The second end should sag no more than 10 mm. If possible, check the hardness of the metal by carefully filing it with a file. The steel in high-quality products is hardened, and therefore is characterized by increased hardness and does not lend itself to filing.

Chain, gears, shoes and tensioner - complete replacement kit

Advice. The main technical characteristics of the chain are its size and number of links, and you need to select the part based on them. If you are in doubt, then do not buy a new spare part without removing the old one with which you can compare it.

If you are updating a chain drive with a significant mileage of the car (150-200 thousand km), then you will have to change all the accompanying elements - gears, tensioner and damper. When the chain has stretched after a run of 50-100 thousand km, it is not necessary to change the gears, but the tensioner must be checked for functionality. Also, don't forget to buy consumables - cover gaskets, O-rings and heat-resistant sealant.

How to replace the timing chain on a Toyota Corolla?

Toyota Corolla is not the most fastidious car, but the timing belt may require repairs. This procedure can be done in your garage. It is not necessary to disassemble the front part of the engine to replace the timing chain.

Method No. 1

If you don't want to take risks and waste a lot of time doing pointless work, use the following method: remove the front cover and crankshaft pulley. This will allow you to get to the desired element without riveting its links. The Corolla can suffer serious damage if the chain opens on its own due to careless operation, and the method of accessing it through the crankshaft will protect you from this risk.

GR mechanism - schematically

To replace, you will need to carefully open the links of the stretched chain, then the broken part is connected to the new one and pulled forward so that the new part takes the place of the old one, holding all the sprockets. The part is pulled out to the place where the disconnected link is located, then you need to rivet the links of the new chain. This method has one drawback, but it is quite significant. By using this method of repairing the timing belt of a Toyota Corolla, you will significantly reduce the life of the new timing chain. Another problem could be the lack of a good connection.
Such a replacement should be done only as a last resort, if you have no other choice.

Replacing the timing chain

The complexity of the procedure lies in the dismantling of attachments and disassembling the power unit, which takes up to 3 hours. Removing and installing a new drive is quite simple. If all elements need to be replaced, then before performing work, be sure to delve into the timing drive structure of your car. Example: on the same KIA Ceed, the gear is pressed onto the crankshaft under heat, so you cannot dismantle it at home. Then disassembling the engine makes no sense, since it will be possible to replace one chain.

Step-by-step instruction

The chain is replaced as follows:

1. Remove the right power unit support cushion.
2. Remove the ignition coils.
3. Remove the cylinder head cover.
4. Remove the serpentine belt tensioner.
5. Remove the right support bracket.
6. Install the piston of the first cylinder into the TTM. To do this, you need to turn the crankshaft so that the mark on it coincides with the “0” mark on the timing cover. The marks on the camshaft drive gears must also match.
7. Remove the crankshaft pulley.
8. Unscrew the nuts and remove the chain tensioner.
9. Unscrew the bolts and nuts and, using a screwdriver, remove the timing cover.
10. Unscrew the bolt and remove the tensioner shoe.
11. Remove the chain along with the drive gear.
12. Replace the chain and reassemble in reverse order.

When installing a new timing chain, pay special attention to the alignment of the marks. If you are not sure of their location, it is worth watching training videos. In addition, it is important to check the condition of the sprockets. If they are worn out, the service life of the new chain will be significantly reduced. Often the tensioner or other elements of the mechanism are replaced with the chain.

Replacing the 2008 Corolla timing chain is no different.

If after replacing the timing belt the car does not start, you need to contact a specialist - probably an error was made during the installation process.

How to tension the chain?

The timing chain is tensioned automatically if the mechanism is working properly. If it seems to you that the chain needs to be tightened, you need to open the cylinder head cover and inspect the mechanism parts - perhaps some of them need to be replaced.