Automatic transmission: Flushing instead of repairing

Automatic transmission: Flushing instead of repairing

The manual transmission is a discontinued model. Modern automatic transmissions have long since overtaken manual transmissions in terms of acceleration, efficiency and comfort. And this also makes it easier for car manufacturers to meet increasingly strict emissions standards. This means: The proportion of automatic transmissions, which is already around 60 percent of all new cars, will continue to rise. Many manufacturers state that the gear oil used is a lifetime filling and does not need to be changed.

However, that is not true. Transmission manufacturers generally recommend an oil change every 60,000 to 120,000 kilometers - depending on the type of automatic transmission and the stress on the vehicle. Dual clutch transmissions should have an oil change every 60,000 to 80,000 kilometers, converter transmissions approximately every 100,000 kilometers. If the transmission is properly used, for example when driving very sportily or by regularly towing heavy trailers, the recommended change interval also decreases. The question “How useful is a transmission oil flush?” In these cases, the answer can clearly be “very useful”.

Due to its design, there is significantly more oil in an automatic transmission than in a manual transmission. Because the gear oil has several tasks: It is used for lubrication, for removing abrasion, for cooling and also for cleaning the individual components. On average, there are six to ten liters of oil in an automatic transmission. If you want to change the transmission oil conventionally, you will only be able to drain around 30 percent of the used oil. The rest remains in the transmission and would also contain downforce.

The only way to completely supply an automatic transmission with new oil is to flush the transmission oil - or to completely remove it and open the transmission. The latter is completely uneconomical for an oil change and is only recommended for repairs. However, flushing the transmission oil is comparatively easy thanks to fully automatic transmission flushing devices and only requires a few steps from the mechanic. That is why it has become an attractive service offer for many workshops.

The question “How much does a transmission oil flush cost?” depends on the hourly rates of a workshop and the price of the gear oil used. Since a car has to go to the workshop for around half a day, the costs can be between 250 and 600 euros.

There are a few signs why the automatic transmission oil needs to be changed: juddering when starting off, hard engagement of the gears, unusual revving of the engine to be able to engage the next gear, possibly unusual noises from the transmission and increased fuel consumption can be the first signs that the automatic transmission needs attention. An oil change is often enough to eliminate the symptoms described. The reason: Modern automatic transmissions are high-performance components that work with the smallest distances and tolerances. Even the smallest contamination due to downforce or reduced lubricity due to old oil can throw the sensitive system out of sync.

When flushing transmission oil with a fully automatic device, the steps are simple: First, the relevant vehicle is selected on the device. The transmission flushing device is then integrated into the vehicle's transmission oil circuit using appropriate adapters. Now first some of the used oil is sucked off and a special gear cleaner is introduced in the same amount.

A cleaning process now begins in which the vehicle is operated on the stage with the engine running for several minutes and all gears are shifted through. This is to chase the cleaner through the entire transmission. Once the cleaning process is complete, the oil can be drained via the drain plug and the transmission oil pan removed, which is cleaned and the transmission oil filter replaced. When everything is reassembled (note: don't forget a new gasket for the oil pan), the actual flushing process can begin.

Here, the gearbox is first brought back to the correct filling level under pressure and the use of new gear oil and then flushed through. The old oil is gradually sucked out and replaced with new oil. This technology makes it possible to remove 99 to 100 percent of the used oil from the transmission, including all deposits and abrasion. The transmission flushing devices indicate when new oil is being sucked out of the automatic transmission and the flushing process can be ended. The devices are designed in such a way that they use scales to constantly measure how much oil has been removed and added in order to precisely meet the manufacturer's specifications.

In many cases, a transmission fluid flush can replace a much more expensive automatic transmission repair. In addition, it is an attractive source of income for workshops, as the purchase of the device pays for itself after just 30-40 flushes. So in the end both win: The end customer, who has done his car and transmission a favor and even saved money in the process. And also the automotive specialist business, which can offer customers more service and at the same time increase their profits with a manageable amount of effort. Conclusion: Transmission oil flushes are a real win-win situation for everyone involved.