Do-it-yourself Nissan X-Trail variator repair: description, technology and reviews

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

The CVT transmission on the Nissan X-Trail has been the subject of controversy among motorists for many years. Someone drives his car, only undergoing scheduled maintenance, and someone has become a frequent visitor to the service station and dreams of getting rid of a constantly breaking car as soon as possible. Why is this happening? When does a Nissan X-Trail CVT repair become a necessity?

A little about the Japanese variator

The CVT-7 variator from Jatco was installed on the Nissan X-Trail car in the back of the T31. In general, the transmissions of this company are considered reliable. They have proven themselves on many foreign cars, such as BMW and Volkswagen. For some time, automatic transmissions were installed on domestic Lada Kalina and Lada Granta.

In addition to their reliability, they attract moderate cost for automakers, however, according to the manufacturer,variator boxes are not repaired, but only to be replaced. When the gearbox is under warranty, this is quite relevant: just replace the broken unit with a new one, but if the warranty has already expired, the individual will have to spend a lot of money to purchase a new box and install it.

In this regard, domestic service stations "learned" how to repair CVTs to the delight of car owners. Carrying out diagnostics, maintenance and repair of the variator at the Nissan X-Trail in Yekaterinburg is available in the same way as in other regions.

The principle of operation of the CVT

The main components of the variator are pulleys and a belt. There is a drive pulley that responds to pressing the gas pedal, and a driven pulley that communicates with the torque converter and transmits power to the engine through it. The rotation from the driver is transmitted to the driven pulley using a belt.

The peculiarity of the CVT is that the transfer of force between the pulleys occurs only due to the friction force between them and the belt. That is why any overload of such a gearbox can lead to defects on individual elements or breakage of the entire structure.

CVT belt tension is controlled by a bearing. If it is faulty, a hum appears, over time, the belt tension becomes less and it begins to systematically slip along the pulleys. The gearbox increases the gear ratio late, or even stops responding to the driver's attempt to increase speed.

The step motor adjusts the gear ratio. It is located in the valve body and monitors the driving mode and the position of the gas pedal. It is he who tells the drive pulley at what speed he needs to rotate. This happens with the help of a special foot of this step motor. It is fragile and subject to wear. If the box "froze" at one speed, it means that the information from the step motor is no longer coming to it. The foot is most likely broken.

Causes of CVT failure

It seems that the owner himself remains the main and only culprit for the repair of the variator on the Nissan X-Trail T31. After all, the variator is a fragile thing, it requires special care and handling.

Here are the most common mistakes drivers make when they don't read user manuals:

1. Warming up the car with systematic gassing. Even in the neutral position of the selector, the variator reacts to the gas pedal. In an unheated box, the belt slips over the pulleys, leaving scuffs on them, and in the box itself, metal chips from them. In this case, the price of repairing the variator on the Nissan X-Trail will be low. It is enough to change the transmission fluid in time and clean the filters.
2. "Gas to the floor" from the start. Fans of aggressive driving and racing races can safely give up to mechanics after 50,000-70,000 km of run. And it’s good if it doesn’t come to a broken belt in the variator. Such sharp starts are fraught with stretching of the belt and its rupture. Failure of pulleys and bearings. Herethe cost of repairing the variator on the Nissan X-Trail will be noticeably higher. Simple MOT will not get off.
3. Riding over bumps and potholes. Inevitable slip on rough terrain leads to overheating of the CVT. And overheating of any node leads to its breakdown. In this case, only diagnostics will show which part of the variator will eventually have to be changed.
4. Towing another vehicle. Gentle CVT is not designed for two cars. Most likely, it will overheat, respectively, and the period until the next MOT will be reduced. The only thing that a CVT can handle is a car trailer.
5. Towing the car itself with a CVT. The instruction manual still recommends full loading onto a tow truck.

Scheduled maintenance and repair of the variator

Timely maintenance and competent use of the CVT make its service life almost eternal. The manufacturer recommends changing the transmission fluid every 60,000 km, respectively, and filters too.

Some drivers find it convenient to take the car to a car service, and some try to do their own scheduled maintenance, saving a little.

If doing maintenance with your own hands is, in general, a simple process, then diagnosing, repairing and replacing spare parts is painstaking work. By what signs can a malfunction in the variator box be determined? Is it worth it to repair the variator on the Nissan X-Trail with your own hands?

Signs of breakdowns in the variator

Determine whattransmission is not so, quite simple. You just need to listen to her:

• car stalls even when you gently press the accelerator pedal;
• the corresponding icon on the panel lights up, and the variator itself turns on the emergency mode (holds a certain gear ratio - does not allow the car to accelerate or move at all)
• vibrations appear in the selector;
• smooth acceleration and braking disappears, as if something is preventing the belt or pulleys from working, jerks or jerks appear;
• Untimely change in the gear ratio (the CVT does not seem to keep up with the driver's maneuvers);
• appearance of noise: hum, crunch, rustling.

Diagnosis

Carrying out diagnostics at the service station is the best option. The specialist will determine the breakdown, make an estimate. After all, the problem can be not only in mechanics, but also in electrics: a wire break, a connector malfunction or, moreover, a control unit. These problems are best handled by a qualified auto electrician.

For example, in Saratov, more than 30 service centers are engaged in the repair of the variator on the Nissan X-Trail. The car owner can choose the one that suits both the customer reviews and the price category.

How to troubleshoot yourself

You can only carry out self-diagnosis visually by disassembling the unit. Before you start, you need to prepare a set of screwdrivers and containers for parts.

1. Remove the lid and pan. It has special magnets that attract metal chips. We clean the pan and change the coarse filter.
2. Remove the pulleys and assess their condition. They must be perfectly smooth. Scuffs and scratches indicate improper operation of the variator (which means that the belt did not have time to turn the shafts, but slipped over them).
3. Remove the belt. If the pulleys are scratched, then the belt will be defective. It's best to replace that too. Otherwise, it may break at the most unfortunate moment.
4. Remove the bearings with a special puller and study them. They should not have any backlash. If the variator hums during its operation, then it is time to change the bearing.
5. All rubber parts should be replaced immediately.

Actually, these are the main problems that you can visually identify and fix yourself. Many will prefer such a budgetary repair of CVTs on the Nissan X-Trail to replacing a CVT box or repairing it at a service station.

Oil change

Like diagnostics, changing the transmission fluid is not difficult. To the delight of car owners, the CVT-7 has a factory dipstick for checking the oil level, which makes it much easier to change it.

1. Work is carried out on a flyover or viewing hole.
2. Warming up the motor and CVT.
3. Remove the engine protection and the front left wheel (in the direction of travel).
4. Half-removing the fender liner.
5. On the left of the variator there is a special hole for draining the waste fluid. We put a container under it and unscrew the cork.
6. We are waiting for about half an hour. Oil is draining.
7. Drain the oil from the sump.
8. The mesh filter must be removed and tried to be washed (for example, diesel fuel). If we succeeded, then we will save on buying a new one.
9. Rinse the bottom of the crankcase and clean it from metal chips.
10. Return the filter to its place.
11. Insert a new gasket into the pan and put it back on the variator.
12. Raise the battery and air filter. Discard the old oil cooler filter. Installing a new one.
13. Returning the battery and air filter.
14. Fill up with fresh transmission fluid.
15. Referring to the instruction manual, check the oil level.

Checking the operation of the variator

After any disassembly of the CVT: whether it is an oil change, diagnostics or repair, it is necessary to check the unit for operability. Nobody cancels the human factor and assembly errors.

It is necessary to set the selector to the neutral position and start the engine. Then skip the lever through all ranges. Switching should be smooth, without the use of additional force. If everything is in order here, you can start a test drive.

You need to move off carefully, only lightly pressing the gas pedal. If all breakdowns are identified and repaired, and the oil has been changed correctly, then there should be no noise or jerks.