As we all know, the quality of automatic transmission oil directly affects the service life of automatic transmission. Usually, when the automatic transmission fails, the inspection of the automatic transmission fluid is the first step! Because the quality of automatic transmission oil is an important basis to analyze the internal problems of automatic transmission.

正常情況下的自動變速箱油色澤光亮，流動均勻。如果自動變速箱油液的顏色、粘度有了變化，則表明自動變速箱油已經變質，此時就需要更換自動變速箱油，當自動變速箱油有了燒焦味或油液狀態有大量粉末狀物及乳狀等，這時說明自動變速箱內部已經嚴重磨損。那么是什么原因會導致自動變速箱油變質呢?

Under normal circumstances, the automatic transmission oil is bright and flows evenly. If the color and viscosity of the automatic transmission oil have changed, it indicates that the automatic transmission oil has deteriorated. At this time, the automatic transmission oil needs to be replaced. When the automatic transmission oil has a burnt smell or a large amount of powder and emulsion in the oil state, it indicates that the internal of the automatic transmission has been seriously worn. So what causes the automatic transmission oil to deteriorate?

1、自動變速箱溫度過高

1. Automatic transmission over temperature

自動變速箱運行時會因為內部元件運動摩擦而產生大量的熱量，高溫會破壞ATF的質量和摩擦特性，加劇內部元件磨損，ATF會變成褐色或暗紅色并發出燒焦的味道，同時油泥/雜質等也會在變速箱內部產生，長期不更換變速箱油，將導致油液變質。

When the automatic transmission is running, a lot of heat will be generated due to the friction of the internal components. High temperature will damage the quality and friction characteristics of the ATF, aggravate the wear of the internal components. The ATF will turn brown or dark red and give off the smell of burning. At the same time, sludge / impurities will also be generated inside the transmission. If the transmission oil is not replaced for a long time, the oil will deteriorate.

2、自動變速箱進水

2. Water in automatic transmission

變速箱進水后油液會出現乳狀，一般進水情況有兩種，種：發動機冷卻液通過散熱器進入自動變速箱;第二種：雨水或洗車水從自動變速箱透氣孔進入。自動變速箱進水后，車輛故障并不會立即反映出來，因此車主要定期對變速箱油進行觀察。

There are two kinds of water inflow: the first is that the engine coolant enters the automatic transmission through the radiator; the second is that rain or car washing water enters the automatic transmission through the vent. Automatic transmission water, the vehicle fault will not be immediately reflected, so the car mainly regularly observe the transmission oil.

3、油面高度差誤大

3. The oil level difference is too large

自動變速箱油位的高低，也將影響自動變速箱油的品質，從而出現變速箱故障。油位過低，油泵將吸入空氣，使油液與空氣混合，這種情況變速箱油會產生大量的泡沫，油位過高，會使行星齒輪和其他旋轉部分浸在變速箱中，發生攪動油液現象。

The level of automatic transmission oil will also affect the quality of automatic transmission oil, resulting in transmission failure. If the oil level is too low, the oil pump will inhale the air and mix the oil with the air. In this case, the transmission oil will produce a lot of bubbles. The excessive oil level will cause the planetary gear and other rotating parts to be immersed in the gearbox, causing the phenomenon of stirring oil.

4、摩擦片打滑

4. Friction plate slipping

變速箱內部離合器、制動器的摩擦元件打滑會引起變速箱油的變質，此時變速箱油液往往呈黑色，并伴有焦味。導致發動機轉速很高，但車速上升緩慢的故障，換檔也會受影響。

The friction elements of the clutch and brake in the transmission will cause the deterioration of the transmission oil. At this time, the transmission oil is often black with scorching smell. As a result, the engine speed is very high, but the speed rises slowly, the gear shift will also be affected.

5、金屬零件磨損嚴重

5. Serious wear of metal parts

如果變速箱油液中存在大量的金屬碎末，這主要是由于變速箱內的金屬零件磨損嚴重，如變速箱內的中間軸、軸承、離合器鋼片等。

If there are a lot of metal debris in the transmission oil, it is mainly due to the serious wear of metal parts in the transmission, such as the intermediate shaft, bearing, clutch steel plate, etc.

6、摩擦材料脫落

6. Friction material falling off

這種現象大多出現在自動變速箱進水后，未進行維修，而只是更換變速箱油后繼續使用，造成的摩擦片脫落的現象。

This phenomenon mostly occurs in the automatic transmission after water, without maintenance, but only after changing the transmission oil to continue to use, resulting in the phenomenon of friction plate falling off.