The problem of defects in the new gearbox housing! 20

Clause. The first and second basically belong to Xiaobai, have you two seen a transmission yourself? Don't mislead people if you don't understand, the 4th floor supports you, yes, judging from the owner's question, the transmission shell he uses is definitely not iron, it should be aluminum alloy, so there will be such a situation.

As long as there is no oil stain on the surface (even if it is cleaned, there will be traces), it will generally not be old, because the transmission is a large piece, the general 4S shop has to transfer the goods from the manufacturer, it is impossible to change without the manufacturer's consent, and if it is bought from the market, the manufacturer has a record, and the No. 4S store can not claim!

I declare that the purchasing manager of automobile manufacturers can see more than 100 such transmissions every day.

It is likely that it was taken out of a scrapped vehicle in a major car accident and repaired for your use. The manufacturer's new gearbox can't have a large area of flaws, you can ask him to take another 10 gearboxes out to see.

The old one, the money you spend is to buy a new transmission, not to buy the old one.

The transmission is made of cast iron in one go.

Yours should be defective and should be replaced.

The mechanic said to you, that's normal, and that's what the brand new gearbox housing looks like, and I haven't seen any cars with polished gearbox housings.

Pacific Automobile Network] If there is a crack in the shell of the automobile gearbox, it is necessary to see how big the crack in the gearbox shell is, if the shell crack is small, it can be welded, and if it is too large, it is not possible to slip and weld, it is recommended to change a gearbox, because the crack is too big and the welding will leak oil.

A ruptured gearbox will cause oil or air leakage in the car, which is very dangerous, and it is recommended to carry out a comprehensive inspection and repair. If there is damage to the end face of the box joint, the paper pad should be thickened appropriately at the damaged place, and if there is oil leakage, the sealing paper gasket should be repaired and repaired, and the same sealing paper gasket should be replaced. The main functions of the gearbox are as follows.

1. Change the transmission ratio, expand the range of the driving wheel rotation torque and speed, so as to adapt to the often changing driving conditions, and at the same time make the engine work under favorable conditions of higher power and lower fuel consumption.

2. Under the condition that the direction of rotation of the engine does not change, the car can drive backwards.

3. Use neutral gear to interrupt power transmission, so that the engine can start and change speed, and facilitate the transmission to shift gears or carry out power output.

4. The transmission is composed of a transmission mechanism and a control mechanism, and a power take-off can also be installed when necessary. There are two ways to classify: according to the way the transmission ratio changes and according to the different ways of operation.

As long as the standard assembly process is complied with, there is no problem in replacing the gearbox housing. If you replace it at a 4S shop, there is absolutely no problem and you can use it with confidence. The gearbox housing is a housing structure used to install the transmission mechanism and its accessories.

In order to reduce component wear and power loss caused by internal friction, lubricating oil needs to be injected into the housing, and splash lubrication is used to lubricate the working surface of parts such as gear pairs, shafts, bearings, etc. Therefore, there is a filler port on one side of the case, an oil drain plug at the bottom, and the height of the oil level is controlled by the position of the filler. Drill radial oil holes on the positive gear of the first shaft and the third gear of the second shaft, and form a radial oil groove on the hub end face of the reverse intermediate gear and the positive meshing transmission gear of the intermediate shaft to smooth the position of the jujube sliding needle bearing.

In order to prevent the lubricating oil from flowing into the clutch from the gap between the first shaft and the bearing cover and affecting its friction performance, an oil seal assembly is installed in the bearing cover, and an oil return groove is arranged in the inner bore of the bearing cover to prevent oil leakage. to prevent lubricating oil from flowing out of the rear end of the second lead return shaft. The oil seal assembly is mounted on the rear bearing cover of the gearbox.

Gaskets are installed on the joint surfaces of each shaft cover, back cover, upper cover, front and rear housing, etc. and apply sealant to prevent oil leakage. In order to prevent lubricating oil leakage caused by the increase of oil temperature and oil pressure when the transmission is working, an exhaust plug is installed on the transmission mechanism seat and on the rear bearing cover of the transmission.

Millions of car purchase subsidies.

As long as the gearbox housing meets the standard assembly process, there is no problem. If it is replaced at a 4S shop, there is absolutely no problem, and you can use it with confidence. The gearbox housing is a housing structure used to install the transmission mechanism and its accessories.

In order to reduce the wear and power loss of parts caused by internal friction, lubricating oil must be injected into the dismantling and closed shell, and the working surface of each gear pair, shaft and bearing and other parts should be lubricated by splash lubrication. Therefore, there is a filler port on one side of the shell and an oil drain plug at the bottom, and the height of the oil level is controlled by the position of the filler. The radial oil hole is drilled on the first shaft constant gear and the third gear gear on the second shaft, and the hub end face of the reverse gear intermediate gear and the intermediate shaft constant mesh transmission gear has a radial oil groove to lubricate the needle roller shaft at the part where it is cracked.

In order to prevent the lubricating oil from flowing into the clutch from the gap between the first shaft and the bearing cover and affecting its friction performance, an oil seal assembly is installed in the bearing cover, and there is an oil return groove in the inner hole of the bearing cover to prevent oil leakage. To prevent the lubricating oil from flowing out of the rear end of the second shaft. An oil seal assembly is installed in the rear bearing cover of the transmission.

Gaskets are installed at the joint surfaces of each bearing cover, back cover, upper cover, front and rear housing, etc., and sealant is applied to prevent oil leakage. In order to prevent the leakage of lubricating oil caused by the increase of oil temperature and pressure when the transmission is working, a breather plug is installed on the transmission mechanism seat and the rear bearing cover of the transmission. (Photo by photo:.)

Li Linwei of Pacific Automobile Network).

Summary. Hello dear, the faults of the car gearbox problems are: 1. Difficulty in gearing:

Including insufficient transmission oil, insufficient viscosity, and failure of clutch linkage; 2. Peculiar smell: If the owner smells the peculiar smell of the gearbox when driving or starting, such as a smell of burnt paste, the owner should be careful at this time, because the coordination of various parts of the gearbox needs to be lubricated, and if the transmission fluid is insufficient, the gearbox will overheat and catch fire. <>

<> car transmission problems.

14 BMW 525 downshift.

The transmission oil has been replaced.

Hello dear, the faults of automobile transmission problems are: 1. Difficulty in gearing: including insufficient gearbox oil, insufficient viscosity, and failure of clutch linkage; 2. Peculiar smell:

If the owner smells the gearbox when driving or starting, such as a smell of burnt paste, the owner of the car should be careful, because the coordination of the various parts of the gearbox needs to be lubricated, and if the transmission fluid is insufficient, the gearbox will overheat and catch fire. <>

<>3. Noise: including the wear of reverse gears or bearings, the owner needs to replace them as soon as possible; 4. Slip gear: normal operation of the gearbox, when the car is stationary, the gearbox gear should stop at the specified gear, but the gearbox gear automatic sliding gear, can spontaneously jump out of the drive gear, turn to neutral gear, the owner should go to the 4S shop in time for maintenance.

The maintenance method of <> transmission is to regularly check and change the transmission gear oil in time, and the equipment can be connected to the car power supply every 50,000 kilometers. Connect the cold pipe of the equipment and the gearbox with matching joints, add automatic transmission cleaner, press the brakes with your feet, and change the gears of the automatic transmission, and you can clean the gearbox. <>

Good evening <> kiss, 14 BMW 525 downshift crash due to the following: engine oil circuit blockage. First of all, we focus on the engine, if the car has a frustration in driving, the engine will definitely not get rid of the relationship.

Engine ignition, air intake, and fuel injector jointly determine the combustion of fuel, which is also the power of the engine. <>

1.Oil spills.

There is oil seepage at the gearbox housing or oil pan, one reason is that the seal is aging and poor sealing; Another reason is that the shell has trachoma due to poor manufacturing processes.

2.The gear engine stalls, does not react, and shocks.

The test gear standard is to start the engine, idle, step on the brakes, into gear, the normal situation is that there is a feeling of entering the gear within a second time, let go of the brake pedal, the vehicle will start slowly without stepping on the accelerator pedal and gradually extract to 10-20 kilometers of speed, this is a normal gear standard, if more than 2 seconds after the gear is positioned to delay the gear, this situation needs to be overhauled immediately; If there is a strong impact feeling in the gear, that is, the positioning of the impact of the gear, it should be noted that any automatic transmission has a certain degree of impact in the gear, if there is no feeling at all, it means that there is a fault inside, but the impact is relatively large is unacceptable, and the problem caused by it is very complicated, including many aspects other than the gearbox; The situation of dead fire in gear is that the engine will die when in gear, this problem is more obvious when the car is cold, and the problem is caused by the problem of the gearbox and other body systems.

3.Hooking D or R, the engine stalls This fault may be caused by the locking solenoid valve being damaged or the locking control valve being stuck.

Engage D or R gear, then release the brakes, and the vehicle does not move. Or the car can travel a short distance after starting the car cold, but the car cannot drive in the hot state. This is usually caused by damage to the input shaft or reverse clutch, or damage to the DR brake.

It may also be that the automatic transmission has serious oil leakage and serious oil shortage; The connecting rod or cable between the shift lever and the rocker arm of the manual valve is loosened, and the manual valve remains in neutral or parking position;

4.The oil inlet filter is blocked; Serious leakage of the main oil circuit; The oil pump is damaged.

The impact and impulse of the vehicle shift during driving are also common fault phenomena of automatic transmissions, which may be caused by the excessive dirtiness of the transmission oil, resulting in the stagnation of the valve body.

5.The gearbox slipped, and the acceleration was weak; Water ingress into the gearbox.

During the driving of the car, there is the sound of the engine idling during the accelerator speed up process, the speed of the car does not increase, and the whole car feels weak, which is mostly caused by the burning of the clutch plate. Water ingress into the gearbox due to external causes causes the gearbox to not work properly, which may be due to oil stringing in the tank or water entering from the gearbox vent cap.

6.Abnormal noise. It is the abnormal sound of the bearing, and the abnormal sound of the general bearing is closely related to the speed, and the higher the speed, the more screaming.

It is the abnormal sound of the differential or the main transmission gear, which generally appears at a speed of 50-70 kilometers, because the meshing surface of the gear is different, and the sound is obvious when refueling, and the sound of releasing the throttle is significantly weakened.

It is the abnormal sound of the hydraulic system such as the oil pump, which is closely related to the speed but has nothing to do with the speed, and the scream is caused by the oil pump when the speed is high. It should be noted that the gearbox system works with the engine, chassis and other parts, and many sounds are mixed together, which is not easy to identify. "

Transmission failures are generally as follows.

1. It is difficult to hang up and frustrated.

Performance: In the process of starting or driving, hanging, picking, shifting is astringent and laborious, as if it was stuck by something, there is a sense of staggering, vibration, frustration, sometimes the cold car is easy to put in gear, and the hot car is difficult to put in gear, with a lot of discomfort;

2. Automatic gear breaking, impact (valve body failure).

Performance: There is no power at the start, the car has obvious shruggedness and frustration when driving at low or medium speeds, and the tachometer hand on the dashboard floats up and down; In the case of pressing the accelerator pedal sharply during medium and high-speed driving, the car slips, and the tachometer needle rises sharply and has an obvious sense of impact; Hung from P gear to R gear and D gear, the car has an obvious sense of impact and breaking gear.

Reason: impurities appear in the gearbox, forming a blockage in the valve body, resulting in poor up and down movement of the valve body, and the oil pressure cannot be adjusted sequentially, resulting in the failure of gear breaking and shifting impact.

3. The gearbox is abnormal and noisy.

Performance: When the car is idling or driving and driving under high load, it hears abnormal noise, even loud noise, and rhythmic and dull sound when shifting gears.

Causes: Dirty inside the gearbox, worn or severely worn bearings, gears and other components, or damaged gear sides.

4. The temperature of the gearbox is too high.

Performance: The computer displays an alarm during driving: the temperature of the gearbox is too high; Or after driving for a while, you feel that the gearbox is overheated, or even hot.

The reason: the inside of the gearbox is often overloaded, and the temperature cannot be effectively controlled!

Shenzhen Xinhuapeng automatic transmission repair, car maintenance, professional gearbox maintenance, maintenance experts around you.

Transmission oil leakage: You can clearly feel that the car starts more laboriously, and although the speed of the accelerator is increased during driving, the car has no obvious signs of acceleration.

Stuttering: In the process of driving, the shock, vibration and frustration generated by the gearbox when upshifting are relatively strong or there is a feeling of stuttering and shrugging when accelerating sharply.

Abnormal noise failure of the gearbox: When the car is idling or driving and driving under high load, it hears abnormal noise, even loud noise, and there is no rhythmic and dull sound when switching gears. It is difficult to hang up and frustrating.

Difficulty in gearing: Hanging and shifting gears are laborious, like being stuck by something, and there is a sense of frustration.

2.The most direct manifestation of damage to the reverse gear is the abnormal sound when driving in reverse gear. 3.

Owners who are accustomed to automatic transmissions sometimes forget to step on the clutch when they do not stop or the clutch is not pressed to the bottom, and the reverse gear is damaged by hanging the reverse gear. 4.Installing floor mats or floor glue on the vehicle may affect the travel of the clutch pedal.

If there is a sound in reverse gear, you look at these 4 points, and then you can rule it out according to your situation.

You're most likely one and two.