The gearbox and the engine are the two major assemblies of a car. Most car owners are aware of maintenance, and there will always be some car owners who will ignore the maintenance of the gearbox. I drove less mileage, and I didn’t change the oil after driving for seven or eight years. I also said I didn’t change the oil before my car had reached 60,000 kilometers! Then what I want to say is that if you leave it on without changing the oil, you will have no problem. If something goes wrong with luck, you will have to overhaul the gearbox. Prevention of gearbox maintenance In addition to good driving habits, correct maintenance of the gearbox is essential.
This Honda Accord 4-speed automatic manual transmission. Sliping, abnormal noises, and running. Based on the owner’s usual maintenance status, he has never changed the gearbox oil. The owner said that he would go to the repair shop to change the oil on time after taking off the insurance, but he didn’t know that the gearbox would also need to be replaced and maintained.
Simply put, daily mechanical wear inside the automatic gearbox will produce some debris, so the gearbox oil slowly becomes dirty or even deteriorates. Failure to dissipate heat well will lead to high temperatures. For example, there are multiple sets of overlapping friction discs + steel discs in the gearbox clutch. Friction discs are inherently a wear part. The high temperature of the gearbox will aggravate the wear of the friction discs over time, and the particles generated by wear will circulate with the gearbox oil inside. Dirty gearbox oil carries a large amount of metal powder, which not only cannot be lubricated, but the debris will also aggravate the wear and tear of the gearbox.
Let’s take a look at the condition of this Honda 4AT gearbox that has not been replaced after being disassembled:
The torque converter must be remanufactured and cut open to clean and repair the inside. Because of its special structure, even cyclic oil changes cannot replace the dirty oil inside.
Remove the torque converter and gearbox oil and flow out like soy sauce. It should have been clear yellow oil:
The internals of the shell are all black when you remove them. Because the oil is too dirty, impurities in the gearbox flow in the gearbox with the gearbox oil, which will block the oil pump, oil compartments, and wear out the valve body.
Youge
The corrosion of oily dirt and dirty oil on the transmission internals cannot be underestimated. Those who say that the gearbox should not be changed can see the consequences. In addition to the ring gear, bearings, friction plates, steel plates, oil pumps, torque converters, other planet carrier ring gears and other accessories all have varying degrees of wear and tear. No photos are taken one by one, because the deteriorating dirty oil is spread all over every corner of the gearbox.
Because the oily photos will reflect light, the friction sheet will ablate, and the steel sheet will have many abnormal wear and scratches
If the gearbox oil is too dirty and not replaced for too long, it will affect the lubricating effect of the gearbox oil. The poor operating environment inside the gearbox directly affects the service life of these wearing parts. After the transmission oil is used for a long time, oil scale and sludge will be formed, which will increase the wear of various friction plates and components
Finally, I would like to say that if the gearbox has symptoms, such as stumbling, impact and slipping, code reporting, and then changing the oil, it will only take away the impurities in the gearbox, but where do the impurities come from? They are friction discs, and the valve body will wear out after a long time. The impurities that have been worn out are taken away, and the worn parts have not been repaired
HuberyFlower 
5 
September 23, 2024 
