49
votes
Accepted
What's the Purpose of Park on an Automatic Transmission?
In an automatic transmission there is a ring with teeth on the output shaft of the transmission. When the transmission is shifted into park a lever called the parking pawl is lowered against the ring. ...
- 16k
26
votes
Accepted
Does a Car Keep Moving If Neither Accelerator, Nor Brake Is Pressed?
In short, find a better driving instructor and, if possible, learn to drive a car with manual transmission.
The long (still simplified) answer:
Does the accelerator control and ensure gas is flowing ...
- 2,022
25
votes
Accepted
How do the latest automatic transmissions match the efficiencies of manual gearboxes?
Traditionally...
The major drawbacks of automatic transmissions were:
parasitic losses in the torque converter, something which manual transmissions don't have.
fewer gears, so a given engine was ...
- 39.1k
22
votes
Why is towing a manual transmission car, in neutral, with the drive wheels on the ground, considered safe?
Manual transmissions (most, but not all) lubricate not through a pump, but through the action of the gears and secondarily through the level of the transmission fluid itself. In some transmissions, ...
- 153k
21
votes
How do the latest automatic transmissions match the efficiencies of manual gearboxes?
A lot of new automatic transmissions (e.g. Volkswagen DSG) arent actually auto transmissions, at least not in the traditional sense. They have a normal computer-controlled dry clutch (well two ...
- 1,350
20
votes
Accepted
What is a governor and what is it used for?
Old automatic transmissions were shifted entirely using hydraulics, not electronics. For this operation the transmission would generate 3 pressures; line pressure, throttle pressure and governor ...
- 16k
15
votes
What are the "1" and "2" or "L" gears used for on an automatic?
To go down hill
By setting L (or 1 or 2), the gear will stay low and you will be able to use engine brake, instead of using brakes all the way down the hill and suffering from fading. The ...
- 1,739
15
votes
Accepted
How exactly does Sport Mode work in an automatic Subaru Outback?
Sport mode will "increase pickup" by providing a more instantaneous response to throttle inputs. As akadian mentioned, the car will stay in lower gears as you accelerate, allowing the engine to stay ...
- 6,037
14
votes
Are manual transmission cars disappearing?
According to NY Daily News, only 6.5% of cars in the United States were Manual Transmission in 2013.
That number may even be an overestimate. More helpful is Fix.com, which actually has a useful ...
- 311
14
votes
Accepted
Does putting an automatic car into neutral at stop lights significantly harm the transmission?
No. Not by any significant or even measurable amount. Constantly using the shifter may, over time, wear the bushes and linkages prematurely but these parts are usually inexpensive and simple to ...
- 1,698
14
votes
Why do you use the "park" gear to park a car and not only the handbrake?
Putting the transmission into "Park" engages the "parking pawl" - essentially a metal pin that locks the output shaft of transmission (and thus the driven wheels) in place.
As to why it exists - it ...
- 9,989
12
votes
Can a car with automatic transmission be damaged by being towed in neutral with the engine not running?
Most owner's manuals state that the vehicle should not be towed with the drive wheels on the ground for longer than x miles or faster than y MPH. The reason for this is that Neutral only disengages ...
- 2,055
12
votes
Accepted
How does the transmission not strip itself when applying the brake?
The somewhat longer answer is that the device that makes what you're asking possible is the torque converter. This device is a pair of curved blades setup as an impeller, and a turbine. The following ...
- 9,326
12
votes
Accepted
Do Manual transmission cars perform better than Automatic transmission?
The difference comes down to the driver. While automatic racing gearboxes can beat a driver when it comes to performance, for the type of vehicle you describe, a manual can perform significantly ...
- 18.6k
12
votes
Accepted
Why is the ATF Level checked with the engine running?
There are two main things about tranny fluid:
Transmission fluid is checked when it's hot (up to running temperature). As the fluid gets up to temperature it expands. If the fluid is cold, it won't ...
- 153k
12
votes
Accepted
Found a 10 mm nut in the transmission fluid
Okay. Lot's of research, long story, found the answer, don't like it.
Overall design of the Nissan B13: one of the things that always impressed me about this vehicle is that it seems to have been ...
- 12.2k
11
votes
Accepted
What should one do to reduce the HP lost at the wheels on an automatic transmission?
The power losses in a MT are primarily do to friction. Everything in a MT is positively locked together, meaning there is no slip anywhere. Beyond friction at least one of the rotating assemblies is ...
- 16k
11
votes
Accepted
Mysterious "5th" Gear on a 4-Speed Automatic?
The transmission has a lock up torque converter.
The torque converter sits between the engine and transmission. It is kind of like a clutch on a manual transmission car. When the engine is idle, it ...
- 8,443
11
votes
Does a Car Keep Moving If Neither Accelerator, Nor Brake Is Pressed?
Note, most of these answers are very specific to an automatic transmission and also a gasoline (petrol) engine -
The position of the throttle generally controls the volume of air allowed to enter the ...
- 24.8k
10
votes
1996 Mustang GT won't start with shifter in Park, but will start in Neutral
The range switch doesn't think the car is in park. On Fords theres an adjustable cable if you look on the driver side of the transmission there will be lever with a cable attached. Sometimes the clip ...
- 10.7k
10
votes
Accepted
How Does a Quick Shifter work in a motorcycle
Why the Quick-Shifter?
Since these are called quick-shifters we'll dub slow-shifting the traditional way of shifting gear. When you slow-shift you usually close the throttle, disengage the clutch, ...
- 1,765
10
votes
Accepted
Bump on the floor in the back of sedans
The hump provides longitudinal rigidity in the unibody. The fact that it also provides a place to route the exhaust is a bonus.
Notice that modern CAD-designed vehicles have much less of an obvious ...
- 1,723
10
votes
Switch from N to D without brake
Should be no problem at all.
The manual is being overly cautious, since the usual case for shifting from neutral into drive is when you're stopped hold the brake will prevent the car from starting to ...
- 14.4k
10
votes
Accepted
Switch from N to D without brake
No harm done
On contemporary vehicles there is no direct mechanical linkage between the gear selector and the automatic transmission.
Instead, the gear selector selects a "state" (e.g. N, D, R, 1, 2....
- 39.1k
10
votes
Accepted
Chevrolet 2008 Suburban, I removed the transmission fluid pan by mistake. Can I just put it back on and refill fluid?
While it's inconvenient, there's no reason you can't resolve this yourself.
The transmission fluid pan has a single-use gasket on it, if you just bolt it back on you run the risk of fluid leaks, which ...
- 16.2k
9
votes
Why doesn't anyone ever repair an automatic transmission?
I know that this is an old question, but I want to provide a brief answer.
Amount of work that is necessary to fix anything inside the transmission is very close to the amount of work that is ...
- 191
9
votes
Are manual transmission cars disappearing?
Short term answer: No. There are a lot of countries where the price difference between a manual and an automatic will matter.
Long term answer: Yes. But because of a different reason, I'd say - ...
- 1,344
9
votes
What are the "1" and "2" or "L" gears used for on an automatic?
Two additional uses alongside engine braking controlling downhill descents:
Low gear, high revs uphill on loose ground like sand
If you need to go up a steep hill on loose terrain like a sandy dirty ...
- 2,628
9
votes
Looking at buying a 1997 Toyota Camry XLE V6 with dark colored ATF, mistake?
95% chance it's just normal wear. The vast majority of car manufacturers recommend an ATF change between 30,000 and 100,000 miles. So if the owner hasn't serviced it in a bit, the brown colour would ...
- 5,245
9
votes
Would not allowing my vehicle to downshift uphill be fuel efficient?
The primary reason to down shift is more power.
The 2 things effecting your gas mileage here are throttle position and RPM. As long as you can stay in 8th at less than half throttle, I would stay ...
- 8,443
Only top scored, non community-wiki answers of a minimum length are eligible