These are questions regarding either manual or automatic gearboxes and their component parts.

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72
votes
17answers
114k views

Does Downshifting (Engine Braking) Cause Extra Wear and Tear?

Does the act of downshifting to slow your vehicle down have any negative side affects? I don't downshift more than one or two gears at a time and I let out on the clutch slow enough that I don't rev ...
26
votes
6answers
13k 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 ...
25
votes
1answer
12k views

Why does the reverse gear in manual transmission cars sound different

When I got a manual transmission car (2003 Kia Rio) I noticed that it makes a winding sound in the reverse gear. Here is an example video that I found that demonstrates the sound. http://www.youtube....
24
votes
5answers
6k views

What is the technical reason the engineer decided the motorcycle gear pattern as follows?

The gear pattern is selected by clicking a lever with your left foot, and is typically laid out as follows: 6th gear (if applicable) 5th gear 4th gear 3rd gear 2nd gear NEUTRAL 1st gear What ...
17
votes
4answers
31k views

Driving in second gear at 65+ mph

I accidentally drove my 2000 Grand Marquis on second gear on the highway. I was going 65 for like 5 minutes and tried to get it to 70mph but the car was shaking, when I realized I put it into regular ...
17
votes
5answers
10k views

Manual transmission at stop: 1st with clutch in, or neutral with clutch out? -OR- Throwout Bearing wear

When sitting in traffic or at a long red light, is the Best Practice to have the car in 1st gear with your foot on the clutch, or in neutral with your foot off the clutch? Some say that you should be ...
15
votes
4answers
5k views

Is downshifting on hills harmful for non-trucks? [duplicate]

Possible Duplicate: Does Downshifting (Engine Braking) Cause Extra Wear and Tear? Since the days of taking drivers ed (many years back). I was told that when you encounter a steep or extended ...
14
votes
4answers
2k views

Why do 5- and 6-speed transmissions typically need different gear ratios?

My 2013 Subauru WRX has a 5-speed manual, and I long for it to have a 6th gear when cruising on the highway. A friend has a 2012 Subaru STI with a 6-speed manual, and I noticed his car runs through ...
13
votes
5answers
30k views

How difficult is it to rebuild a transmission?

I have a 1984 Toyota Supra that is now exclusively a track car. The last round out we let some less experienced drivers take the wheel and they basically destroyed the transmission. Nothing but 4th ...
13
votes
2answers
25k views

Engine revs high 5th gear manual transmission

What might cause a car with a manual transmission that in 5th gear when given a punch of gas revs to very high rpms – with no power transferred to the wheels (i.e. the tachometer and speed go ...
12
votes
4answers
168 views

What would happen if you shifted into reverse while you are going forward?

First, I am talking about manual cars and I know this is considered impossible because of the synchronized gears, but lets suppose that you can manage to shift gears (For example you could shift into ...
12
votes
4answers
13k views

Causes of early clutch failure EXCLUDING driver style

UK 61 plate, Ford Diesel Mondeo Estate, Econetic: clutch replaced at 31,800 miles; failure caused by 'driver style' I use my car daily for commuting and for business. It's supplied to me as a company ...
12
votes
5answers
29k views

2003 Chevrolet Impala - Jerks after Stopping

I have a 2003 chevy impala. When I hit the gas (whether it be a light tap or hit it pretty hard), my car kind of waits a second, jerks and then takes off (revs go kinda high when it's waiting). To ...
12
votes
4answers
12k views

What is the life expectancy of a Honda Civic Hybrid Continuously Variable Transmission?

I have a 2006 Honda Civic Hybrid with continuously variable transmission (CVT). At the 90k tuneup, the mechanic added 3.5 quarts of the regular automatic transmission fluid. At 110,000 miles, the ...
11
votes
4answers
1k views

Do cars go from Drive to Neutral on their own?

While stopped at a railroad crossing in my A/T Honda CRV with my car in Drive and my foot on the brake; does my car eventually go into Neutral on its own if I'm there for while?
11
votes
3answers
22k 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 ...
11
votes
1answer
144 views

Why don't cars use Sequential gearboxes?

I have always felt that the Sequential Gearbox configuration is much much faster than a ordinary gearbox used in cars. Why is this design used ? Any advantages? Note: I am aware that racing cars(...
10
votes
3answers
1k views

How does the transmission not strip itself when applying the brake?

Quick question bugging me: Obviously the car moves forward when neither applying the brake nor the accelerator. How does this not damage the transmission when the brake is pressed? I first ...
9
votes
11answers
54k 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 ...
9
votes
5answers
109k views

Car shakes when in gear at red light

I bought a '96 Toyota Camry about a month ago. When I first turn the car on and the engine is cold, I can have the car stopped (in gear) and it will not shake. The idle RPMs will be at 1000. After ...
9
votes
1answer
142 views

How does Audi Crown Gear Center Differential work?

I'm trying to understand how the engagement of the clutches is varied. I see the power is transmitted through the center input shaft and is transmitted through the four pinion gears, but I don't ...
8
votes
3answers
288 views

Switching gears without clutch

I drove manual car for a long time but never tried to switch gears without clutch. Question: given that clutch-less shift is executed properly, does it take a toll on transmission in any way? For ...
8
votes
3answers
828 views

How Does a Quick Shifter work in a motorcycle

I have often seen motorcycles like the BMW S100RR and the famous Ducati Panigale with Quick Shifter technology which allows seamless gear changes. I want to know how these things work mechanically ...
8
votes
4answers
866 views

What problems may occur if clutch is not used?

I was curious about what problems may arise if clutch is not used when shifting gears. Are the problems similar for both cars and bikes?
8
votes
1answer
420 views

Why did manufacturers go to other than 1:1 transmission ratios?

While reading this question it came to mind: Why did manufacturers start building transmissions without a 1:1 ratio? In the older transmission you'd see the 1:1 ratio all the time, either as the ...
8
votes
4answers
28k 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
39 views

I own a 1989 Mercedes 560sec that has rpm surges for no real reason

It happens once or twice a month, I could be doing 60 mph, and its almost redlining at 5000 rpm!. Once the vehicle gets to normal operating temperature, and I turn it off for a few minutes and turn it ...
8
votes
2answers
80 views

Gear selection on 6 speed box

Hi I have a Peugeot 308 1.6 ehdi with a six speed manual gearbox and have noticed that when selecting first or sixth gear it does not go in smoothly it can be notchy or clunky this is quite annoying ...
8
votes
0answers
55 views

Torque convertor shudder?

I drive a 2011 GMC Sierra 2500HD ex-cab 2wheel drive with a 6.0 gas engine and a six speed 6L90 automatic transmission. I have started noticing what I believe is called "shudder" from my tranny under ...
7
votes
4answers
49k views

Shift “Grinding” Issue?

Lately I've been noticing a grinding/resisting force and sound when I shift from first to second gear in my 2003 Jetta GLI. It is ruining driving for me because every time I shift from first to second ...
7
votes
2answers
168 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 ...
7
votes
2answers
939 views

Why do hybrids still use mechanical transmission?

One of the comments on this question reminded me of something I've been wondering for a while. Given that engines get the best efficiency at peak torque, why do most hybrid cars still use a mechanical ...
7
votes
2answers
338 views

Optimal RPM range for manual transmission

Are there optimal RPM ranges for different vehicles? I've been told it's better for the engine to drive at slightly higher RPMs (e.g. 2500-3000 for my Tacoma) than low (1000-1500). I understand a ...
7
votes
2answers
16k views

Clutch pedal no longer provides resistance, clutch won't disengage, what likely failed?

A little background information: Car: 1993 Ford Mustang LX [2.3L I4], 5-speed T5 transmission. I bought the car a few months ago, according to the previous owner the clutch was replaced fairly ...
7
votes
2answers
2k views

Motorcycle transmission occasionally pops out of gear

I'm having an issue where the transmission will occasionally downshift by itself during a fast acceleration. I have a 2005 Suzuki Vstrom 650 and it's been a great bike so far. At pretty high revs, 9k-...
7
votes
2answers
2k views

Any truth to the “myth” about changing transmission fluid in older vehicles?

I have had people give me anecdotal stories (friend of a friend type thing) about changing the transmission fluid in vehicles with 150,000+ miles, especially those that haven't had regular ...
7
votes
1answer
110 views

Should I change transmission fluid if it's black?

I bought a vehicle couple of weeks ago. I checked the transmission fluid today, and noticed it was black. Should I be worried and immediately go change it? Part of me wants to get it changed since I ...
7
votes
1answer
102 views

Why am I not moving after starting car and shifting to Drive?

So I have had this issue for the last couple months where when I first start the car, shifting to Drive (automatic transmission) doesn't do anything. Pressing the gas only revs the engine, as if in ...
7
votes
2answers
146 views

Yamaha YZ125K 1983 transmission bearings

I'm restoring an engine and am unable to locate 3 gearbox bearings. Identifying mark is either IXO or IKO. It is a needle roller bearing type and sits RHS crank case 1/3rd gear shaft. Mark clearly ...
6
votes
3answers
7k views

Is it bad to drive slow at low rpms in 4th or 5th gear? Do you get better gas mileage?

Obviously running your engine at too high an RPM for too long isn't good. But what about running it too low? not so low that it stalls or lugs, but within around 1,000 RPM? Would you get better ...
6
votes
4answers
8k 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
3answers
2k views

Is Redline Lightweight Shockproof appropriate for an aging 2004 Subaru Impreza manual gearbox?

I have an aging (but wonderful) 2004 Subaru Impreza WRX with a manual gearbox. For some time, I have noticed that the synchros have begun to feel worn with the stock dealer-issue oil. Shifts are ...
6
votes
2answers
2k views

1st gear hard to engage unless stopped, Subaru 2004 Impreza Outback Sport

Since I've bought my 2004 Impreza Outback Sport, I've had a problem with shifting into 1st gear. First gear is generally difficult to engage while moving. You can just force it, but it's really ...
6
votes
4answers
2k views

Subaru Outback Towing vs Coasting

We just recently got a Subaru Outback. It is a manual and has AWD. The dealer told us if we need it towed, it has to go on a trailer, and can't be towed with wheels down. I understand that this can ...
6
votes
1answer
943 views

Clutchless Downshifts Using Throttle Blip on a Motorbike/Sequential Gearbox

This is with respect to non synchromesh, sequential transmission. Ducati along with several after market systems, implement clutchless downshifts by automatically applying a slight throttle to unload ...
6
votes
1answer
528 views

Transmission damage due to uneven tread wear on AWD vehicle

I have a 2013 Subaru Impreza with a continuously variable transmission with ~40k miles on it. About two months ago I blew out the front right tire and took it to a tire shop. The folks at the tire ...
6
votes
1answer
187 views

Is it bad to shift into reverse while still moving forwards?

I often put my manual car into reverse while still moving forwards. I do it at less than 10mph. However, sometimes the gears crunch. Am I doing any damage by doing this? Why do the gears crunch? I ...
6
votes
2answers
3k 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
2answers
2k views

Why won't my Honda Rebel shift when idling?

I recently ( and successfully ) rebuilt the engine of my '09 Honda Rebel; she's running well but doesn't want to change gears when idling. If I'm moving she shifts gears without any hanging, grinding,...
6
votes
1answer
87 views

Effects of shutting off Nissan altima (or any car) while in drive

Every now and then when I get home after a long day, I pull into my driveway and while the car is stopped (foot on the brake), I turn the vehicle off without putting the vehicle in "Park". Car is ...