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

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30
votes
3answers
30k 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 ...
22
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 ...
18
votes
8answers
123k views

What's the point of the D3 gear in an automatic transmission?

My Honda Civic has a D gear and a D3, which apparently prevents it from going into 4th. Why would I want to do this? What is it good for? Does it make my fuel efficiency better or worse? Does it ...
18
votes
2answers
7k views

Why doesn't anyone ever repair an automatic transmission?

I am old enough to have had about four transmission failures spaced over about 40 years and at no time did any mechanic ever offer to “fix” it; the only diagnosis has been a complete rebuild. This is ...
16
votes
2answers
10k 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 ...
15
votes
4answers
936 views

shifting stops when critically low on gas

I have a 1999 Dodge Dakota. It is a V6, 3.9 Liter, auto transmission. I have a weird problem that no one has been able to answer for me. HOW I CAME TO REALIZE THE PROBLEM: One day I was driving ...
13
votes
1answer
793 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 ...
11
votes
1answer
8k 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 ...
9
votes
3answers
24k 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 ...
9
votes
11answers
26k 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. ...
8
votes
4answers
21k 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 ...
8
votes
1answer
699 views

I'm stupid and added tranny fluid to my coolant tank. What can I expect?

Title pretty much says it all. I'm a computer guy, not a car guy. I saw a bunch of red fluid coming out of my vehcile, assumed it was tranny fluid. Turns out it was antifreeze. This means the bit of ...
7
votes
3answers
13k views

What disadvantages a car with 4-speed transmission have compared to 5, 6 or 7 speed with similar engine?

This seemed to be most relevant site to ask my question. I am planning to purchase a new car and my shortlisted car has 4 speed automatic and 1.6 litre engine. The thing that worries me is that it ...
7
votes
4answers
27k views

Can I use a Dexron III automatic transmission/power steering fluid where a Dexron II is required ?

more generally speaking are 'higher Dexron numbers' also fulfilling the specifications of the lower number fluids ?
7
votes
2answers
59 views

Normal Operating Temp for an Automatic Transmission

While I was able to find information on testing the ATF temperature sensor in the GF4A-EL manual I've got: I was unable to find any info on the normal operating temperature of the transmission. ...
7
votes
1answer
1k views

How can I be sure of the reading on my automatic transmission fluid dipstick?

This may seem like a silly question. I've been trying to read the dipstick for my automatic transmission fluid but am having a very difficult time determining the level. The fluid is very light and ...
7
votes
1answer
36 views

My rpms are going high and my mph take a minute to go higher on my GMC Yukon

When I put my truck in drive and step on the gas the RPM's go up to 3,000 but my MPH will stay at 10-15 When I let go of the gas a little bit I can feel the truck kind of pull and the RPM's will go ...
7
votes
1answer
35 views

2005 Mazda 3 at warning light at cold start ups

I've noticed recently that my mazda 3 on cold starts would show the at warning light. When I start it, it normally flashes it for a few seconds then disappears. Then when I pull it out of the garage, ...
6
votes
11answers
43k 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 ...
6
votes
7answers
37k 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 ...
6
votes
1answer
175 views

What should one do to reduce the HP lost at the wheels on an automatic transmission?

I have a 1990 Toyota Supra Turbo 4 speed auto. I've done some research about automatic transmissions and manual transmissions and what are the positives and negatives of each. (For example, MT is said ...
6
votes
3answers
6k 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 ...
6
votes
2answers
2k views

What is the difference between an automatic and an AMT

I have seen many recent car launches in my home country which claim to have something called as an AMT or Automated Manual Transmission. I am curious to know how is this different from a traditional ...
6
votes
3answers
2k views

What determines when an automatic transmission shifts?

I'm working on developing an automatic bicycle (mostly microcontroller based) and I'd presume I'd be shifting in a similar way to a car. So my question is, what factors does the transmission take into ...
6
votes
1answer
56 views

How come gears don’t normally change in an automatic car?

I know that there is a similar question here, and another one here that asks when an automatic gearbox knows how to change gear, but I want to know exactly how it does that. It was brought to my ...
6
votes
1answer
35 views

Will increasing line pressure increase torque capacity?

I was wondering if one were to increase the line pressure sent to the clutch packs/bands on an A/T would that increase the torque capacity of said transmission? I figure it would because it would ...
6
votes
1answer
43 views

2000 Celica engine dies or shakes when I pump gas

I have a 2000 Toyota Celica. At first it used to slip gears and then I had a mechanic check it out. He said its a solenoid in the transmission which he changed. The car sputters sometimes when at ...
6
votes
1answer
3k views

Push start a car with automatic transmission

Is it possible to push start a car with automatic transmission? Use case: Let's say the battery is dead or you have a bad starter. I know this can be done on manual cars by putting the car in to gear ...
6
votes
1answer
169 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
2k views

Ford Focus won't rev high when slipping on snow

Why doesn't my 2010 focus allow me gun it when it starts slipping in snow? It makes it impossible to get out of even a tiny bit of snow. My civic never got stuck because I could always just gun it, ...
5
votes
2answers
4k views

How to put 1997 Toyota 4Runner in neutral with dead battery?

My ’97 Toyota 4Runner with automatic transmission is parked head first in a small garage with a dead battery. I need to put it into neutral to push it out on the driveway so I can jump-start it. (This ...
5
votes
4answers
478 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 ...
5
votes
1answer
26 views

Motor and radiator problem will there be and damage to motor or anything [duplicate]

Hi guys ive got one question i was looking over this car i was going to buy and there was engine oil in the radiator i ask the guys why it was in there he said he didnt have enough coolant to fill it ...
5
votes
1answer
92 views

GF4A-EL Transmission Flush

I just got a 98 Mazda 626 2L and need to flush the atx fluid, it's really dirty brownish red, but not burnt and I didn't notice any particles in it. I think the car has a CD4E tranny ( it turns out ...
5
votes
3answers
307 views

Honda FIT GP1 HYBRID 2011 knock

in my auto gear honda fit gp1 hybrid car, (mileage 56 000 KM) I had a engine tune up and changed my injectors (8 injectors) last month and after 2 weeks i started getting a slight knock (jerk or ...
5
votes
1answer
3k views

Automatic Transmission or Differential Backlash (Play)

I noticed that my car has what it seems to be significant differential play. I have a 1993 Acura Integra with automatic transmission. What I mean by play is simple: say I jack up only one front wheel ...
5
votes
1answer
132 views

Car cranks but will not start after transmission replacement

The 2006 Infiniti G35 would crank but not start after a transmission replacement. I found 2 transmission codes. U1000 which is a CAN bus code and P1815 which is the manual shifting code. It is an ...
5
votes
1answer
8k views

Ford Escape won't shift into gear, O/D light flashing

I've got a 2002 Ford Escape (automatic transmission) that will start fine and reverse without any problems, but when I put it in drive and try to pull forward, it remains in idle. I can hit the gas ...
5
votes
1answer
2k views

Grinding Sound at Specific RPM/Speed

I have a 2011 Ram 1500. For about a month I thought I was hearing a clunk between 2nd and 3rd gear. I finally decided to listen carefully by turning my radio off. I now certainly notice it, but it is ...
5
votes
1answer
39 views

Engagement delay when shifting from neutral to drive or reverse

My 2001 VW Eurovan (T4) has automatic transmission and about 160k miles on the clock. When I use the transmission selector to move from N to D or from N to R, there is a noticeable delay until I feel ...
5
votes
1answer
1k views

2004 Chevy Malibu jerks when deceleration is followed by acceleration between 25-40 mph

I recently noticed that when coasting or breaking is followed by acceleration (seems to be only when the car is moving between 25 and 40 mph) that there is a slight jerk. After recreating the problem ...
5
votes
0answers
44 views

Th400 Transmission help

I pulled my Th400 out of my K20 Chevy and I'm in the middle of rebuilding it and I was resembling it and when I went to put the completed gear train assembly in it and the center support assembly gets ...
4
votes
4answers
3k 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 ...
4
votes
2answers
1k views

How hot is “HOT” on a transmission fluid (ATF) dip stick?

I want to add some fluid additive (Lucas) to my transmission, but I don't want to overfill it. The dipstick has add, warm, and hot for measuring. So how hot is the hot level? My temperature gauge ...
4
votes
1answer
234 views

Does towing an automatic transmision car in neutal with engine not running will damage it?

My daughter had a friend tow her 1996 chevy. automatic transmission without engine running while in "N" SLOWLY for probably 7 or 8 miles distance. Do you think she has damaged the transmission? The ...
4
votes
3answers
883 views

Automatic Transmission: Best practice when waiting at the red light - N or D?

My main concern is the longevity of the engine and transmission. I see conflicting view points on the internet. Some say changing from D to N and back constantly will cause extra wear on the ...
4
votes
3answers
39k views

What is ECT Mode for? - Toyota Cars?

I'm not sure if this is a feature on Toyota cars alone, but I currently drive a '99 Avalon XLS and in addition to the D3 mode which I know disables overdrive, right above the radio near the top of ...
4
votes
1answer
51 views

will not start, when I just had driven it about a hour ago

2003 grand am 4 door automatic,everything works, lights, radio, windows,buzzes when key is in ignition. I hear nice noise, if it was the battery all the other things in the car would not work. What ...
4
votes
1answer
155 views

How to Detect a Bad Transmission When Buying a High Mileage Vehicle

Rebuilding a transmission is one of the most expensive things that can be done on a car and I've been told it's one of the main reasons people dump cars other than timing belt issues. I've read ...
4
votes
2answers
741 views

Better to repair a CVT or replace with a used one?

Our 2003 Honda Civic Hybrid transmission died. Honda gave us an estimate of $4500 to replace the transmission. We took it to a different mechanic who suggested that instead of replacing the whole ...