What to do if transmission fails
In most cases, this failure shows itself when gears all of a sudden are not shifting anymore. The second sign of that? The gearbox gets jammed on a shifted gear or (with the engine shut-off) after having unsuccessfully tried shifting into every gear, with a bit of magic (called the brute force effort) you manage shifting into one of the gears. Therefore, even such failure allows you to reach the repair shop under your own power without much difficulty. All you need to do is throw in any gear, press the gas to the max and gently release the clutch.
Just don’t forget: although the vehicle CAN pull away on any gear, the payback for such luxury would be steep – a burnt out clutch. Keep this in mind when choosing a mode of motion.
It is far worse when it’s an automatic gearbox that breaks down, as it shifts the gears on its own, which makes it impossible to manually shift a gear in case of failure. Fortunately, when it comes to the newer generation of gearboxes, there still is a built-in capacity for that, and if you suddenly see a red light on the dashboard and the gearbox stops changing gears – this is the emergency drive mode.
The emergency mode allows you to drive without hard accelerations for a short time, sufficient to reach the nearest service station. That being said, you must never accelerate the engine above 2000 rpm! Otherwise, the primary pump, forced to operate in overload mode for a prolonged period, will come apart, and the gearbox breaks down.
We would like to remind you that the cars with automatic transmission, transiting from point A to point B not under its own power, absolutely must be transited by towing! For towing at speeds over 40-50 km/h (depending on the car brand) and at distances longer than 50-100 km (also depending on the car) can damage the gearbox constructed to transfer torque from engine to wheels, rather than the other way around. Emergency mode is also intended only to drag you out of the middle of nowhere back to civilization, not for track racing.
However, there are a couple of bright spots to this story. The first one is most automatic gearbox failures originate from incorrect internal actuating. Such bummers are often a one-time happening and the “emergency mode” is in no way a must. You can just turn it off (the instruction manual of the particular car describes the procedure) and continue your ride. The issue should be forwarded to a repair shop only in case this “glitch” repeats itself 3-4 times. The second bright spot is those “glitches” are relatively inexpensive to fix. It is much worse if the car ceases to drive at all! Well, that’s when the engine is running, the gear is put in, but the car stands still. In that case, you should immediately switch the engine off! Then take a look around and evaluate whether you are doing everything properly.
The most common reason of this malfunction (about 90% of the cases) is the driver that forgot to take off the parking brake. Another 9% fall into the “wrong gear” category. One of the possible reasons from the remaining 1% is the tube connecting the gearbox with oil cooler breaking off. When that happens, the gearbox oil is discharged within a minute or two, and the gearbox is out of whack.
Subject to the engine being off at that moment, replacing the tube and refilling the oil
to the adequate level will revive the automatic gearbox in 90% of cases. If the engine continues to spin the dry gearbox – you can just as well kiss it goodbye. The gearbox components cannot function outside of the oil pan; it’s a matter of minutes before it dies. It’s acceptable to start the engine only after checking the gearbox oil level.
In fact, if the gearbox is out of order, it is a good idea to get off its back and refrain from experimenting with it to avoid additional damage and unnecessary repair costs – do yourself a favor and call a tow truck right away.
There are a few more unpleasant moments when you know for sure the automatic gearbox is busted. So, if cold engine car is jerking, while during the warm up it’s business as usual – it a sign of a lack of oil. When it’s cold it is insufficient for operation, and when it warms up and expands – the pump begins to operate regularly. There is a big risk to break down the gearbox – fill up the oil immediately!
Wheelslip during gear-changing is indicative of frictions wearing out: time to reassemble the gearbox due to mileage. If the car is having trouble accelerating to 50-70 km/h, but after that proceeds as usual, it means that the overrunning clutch is rotating loosely in both directions. A reassembly is required. And on the contrary, when a car accelerates freely, but can’t go faster than a certain speed limit, it means the torque converter clutch is jammed. The very same reassembly.
And remember: overheating is the most common reason of automatic gearbox breakdowns. To avoid unnecessary trouble during sitting in traffic on dog days it is recommended to change the gear to neutral. Speed loving daredevils specifically – we recommend that you install additional cooling radiators on your gearboxes.