Questions regarding automatic gearboxes, and associated parts such as torque converters

learn more… | top users | synonyms

10
votes
5answers
33k views

Can coasting in neutral damage an automatic transmission?

When I drove a manual transmission, I got in the habit of shifting to neutral on long, shallow grades to save fuel. Now I'm driving an automatic (specifically, a recent Corolla) and still doing it. ...
18
votes
2answers
11k views

Why doesn't the engine stall out when you come to a stop with an automatic transmission?

When you come to a stop with a manual transmission you have to push the clutch in or take it out of gear to keep the engine from stalling out. What keeps the engine from stalling in an automatic ...
12
votes
1answer
10k views

How does an automatic gearbox know when to change gear

As the title suggests, how does an automatic gearbox know when to change gear, for example, how does the autobox know to shift down when you hit a gradient for example, also how does it know to shift ...
7
votes
6answers
44k views

Strong vibrations when idling even after replacing engine mounts (automatic transmission)

I have a '93 Acura Integra with automatic transmission. Ever since I got it some time ago the car has been vibrating a lot when stopped at a light, for example. The vibration is worse when in gear ...
8
votes
4answers
27k views

Automatic transmission: Is shifting to neutral while approaching stops bad?

This is not with the intention of saving fuel (as I have seen many answers assuming savings in fuel while doing this). But I have this habit of putting the vehicle into neutral before approaching ...
9
votes
3answers
29k views

Switching from Reverse to Drive - always stop completely?

I've been told by a couple people that it's really bad for a car to be shifted from Reverse to Drive while the car is still moving backwards. Is this true? In my experience: On automatic cars, this ...
7
votes
2answers
140 views

Do Manual transmission cars perform better than Automatic transmission?

I'm stuck between choosing a car available in both automatic transmission (CVT) and Manual transmission (6 speed). I wanted to know which one will perform better in the following aspects (considering ...
2
votes
2answers
1k views

On a BMW E46 330Ci, is it necessary to pull the handbrake lever when you're in 'P' mode?

My flatmate drives a 2001 BMW E46 330Ci automatic transmission. I sat next to him while he drove us to the supermarket. When we arrived, I noticed that he only put the gear lever into 'P' and switch ...
1
vote
0answers
47 views

Auto transmission just stopped working while I was driving

While I was driving, my cars automatic transmission suddenly would not work in drive or reverse but the motor was still running. Does someone know what the problem could be?
9
votes
11answers
51k views

Use of Neutral Gear in Automatic Transmission

I am new to driving A/T cars and I am trying to understand the use of Neutral(N) gear. Should I shift my gear from D to N when my car comes to a complete halt on a red light or somewhere else? As per ...
34
votes
3answers
33k views

Is there a way to put Prius with dead battery into neutral?

I own a 2010 Prius. It has a dead battery, front facing forward in my garage. I do not have long enough jumper cables. I’ve searched the Internet. Did Toyota really create a car that cannot be put ...
6
votes
4answers
7k views

Durability of automatic transmission boxes versus durability of manual transmission boxes? Their lifetimes?

My friend is against cars with automatic transmission because he thinks that they break easily and that their repairing cost a lot. He thinks that it is impossible to maintain an automatic ...
24
votes
1answer
3k views

What's the Purpose of Park on an Automatic Transmission?

When one wants to park a manual transmission (MTX) vehicle, one puts it in neutral, and engages the emergency / parking brake. With an ATX vehicle, the practice I've learned is to put it in Park, and ...
8
votes
4answers
2k views

What are the “1” and “2” or “L” gears used for on an automatic?

In a car with an automatic transmission, we are normally greeted by the acronym PRNDL, or in some cases (older cars) PRND21. I know that the L, 1, or 2 will cause the transmission to stay in a ...
4
votes
5answers
4k views

Does switching to neutral on an automatic transmission improve braking for immediate stopping?

I've been told that when needing to brake quickly, throwing the gear into neutral on an automatic transmission actually allows for better/quicker braking. I understand how things work pretty well but ...
14
votes
1answer
1k views

What is a governor and what is it used for?

I was watching a classic car restoration program on YouTube in which they were working on a '50s Cadillac with an automatic transmission. The mechanic in the video diagnosed a transmission glitch as ...
6
votes
1answer
33 views

1998 lincoln continental with fluctuating idle when put in gear only (drive/reverse)

I have a 1998 Lincoln Continental. It has 124k miles on it. The history of the transmission maintenance are as follows: Fluid and filter was changed at 29k miles Fluid was flushed at 86k miles Fluid ...
6
votes
1answer
270 views

Excessive Vibrations in Drive when holding down the brakes

I'm working on a 98 Mazda 626 GF 2L with an automatic transmission. While I'm used to driving manuals, I would say that the amount of vibration when sitting stopped in drive with the brake on seems ...
5
votes
4answers
300 views

Automatic car won't start, steering wheel won't turn, key just makes car click etc - but radio works?

Someone else was in the driver seat and they were trying to drive. At one point I took out the key and when he put it back in the car wouldn't start. This was yesterday and it still won't start. The ...
5
votes
4answers
670 views

How easy is it to overfill transmission fluid?

I was helping out a friend yesterday who was facing some issues with a transmission-related CEL on his automatic 2003 Mazda6. When we checked the ATF dipstick the transmission fluid was a clear ...
4
votes
1answer
88 views

Banging sounds coming in front of my car

I'm having a banging sounds coming from the front of my car. Usually they appear after 5-10 meters when I'm driving. It's like one small knock and then around 5-6 more knocks and then they stop until ...
4
votes
1answer
867 views

Could too much transmission fluid cause problems?

Is my reasoning here a plausible explanation for the issues described below? Background The CEL on my friend's 2003 Mazda6 lit up yesterday, along with a flashing HOLD light. We hooked it up to a ...
3
votes
1answer
1k views

How to add transmission fluid with no dipstick?

I have a 2003 chevy cavalier, and just replaced the radiator due to a transmission fluid leak into the antifreeze. I don't know how much fluid was lost because the transmission was designed without a ...
3
votes
2answers
1k views

Difference between “dumping the clutch” and N->D in an auto?

What's the difference between dumping the clutch, and going from N->D at high RPMs with an automatic transmission? Will this cause any damage to the vehicle?
3
votes
4answers
3k views

RPM jumps up & back down at 40mph

My question is for a 2006 Dodge Magnum, 2.7 liter engine. Just over the past month or so, I noticed when I'm cruisung, just coming from a dead stop, when I'm at 40 mph my car kinda feels like it ...
2
votes
0answers
89 views

Transmission Fluid Change - High Mileage Vehicle [closed]

Should I replace the ATF in a 2007 Honda Odyssey w/ 208,841 miles? Numerous shops advise against drain/ refill. I last changed @ 144k & was advised not to do it ascI could encounter transmission ...
2
votes
1answer
1k views

2006 Cobalt SS - Traction Control Light & Hard Shifting

I drive a 2006 Cobalt SS (not supercharged) with the 2.4L engine. In the last month or so the traction control light has been coming on periodically. Turning the engine off and back on causes the ...
2
votes
1answer
1k views

Manually shifting an automatic transmission?

My car has been rather sluggish lately - both ABS and TCS lights are on, which means there is a sensor error somewhere. I haven't had the time to look for and fix said error, but I have had to drive ...
2
votes
1answer
6k views

Why is my car hesitating to accelerate only when I first start my car?

I've got a 1999 toyota corolla with over 170K miles, and I've had my fair share of problems over the years. Currently, I have this problem that my car seems to hesitate accelerating when I first ...
0
votes
2answers
625 views

In an automatic transmission, what decides to change gears? [duplicate]

So say there is an automatic transmission in a car. Is there a computer inside the transmission that decides to change gears, or is there a computer in the car that tells the transmission to change ...