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Old 11th May 2014, 13:20   #316
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Default Re: Automatic Transmission v/s Manual

Quote:
Originally Posted by Spinnerr View Post

Is engaging parking brake really required in Automatic cars?
No question about it, parking brake is always required whether manual or automatic.

Parking pawl: It's a pin like device that locks and prevents the rotation of drive shaft.
It's present on all automatics. (Torque converter automatics)

The ideal method:
  • Parking pwal is engaged when you put the lever in "P" mode.
  • It's not recommended to use parking pawl alone to stop your vehicle as it puts lots of stress on drivetrain components when parked on inclines.
  • If the parking pawl breaks, you'll end up spending a lot of $$$ for repair.
  • The ideal practice is to use engage the handbrake first and then slot the lever into "P" mode. This was, you apply brakes to hold your vehicle and the pawl is not stressed much.

Note: The above points apply to a torque converter transmission.
I think DCTs would just engage the lowest gear. They are two parallel manual boxes anyway.

I would appreciate it if anyone could throw light on how the transmission in a CVT takes the stress while parking.
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Old 11th May 2014, 13:39   #317
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Default Re: Automatic Transmission v/s Manual

Quote:
Originally Posted by D4D View Post
Parking pawl: It's a pin like device that locks and prevents the rotation of drive shaft.
Thanks for the exact word. I was able to dig out more details.

Last edited by FlyingSpur : 3rd January 2017 at 01:38.
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Old 7th May 2015, 17:46   #318
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Default Re: Automatic Transmission v/s Manual

I recently bought a Toyota Fortuner with automatic transmission. I am driving an AT car for the first time and have been going through different forums in BHP to learn more. I could find answers for all my questions till now except for one.

My question is: Can I shift from D to D-4 or 3 or 2 or 1 while the car is moving? I saw few discussions on the same topic but could not conclude.
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Old 7th May 2015, 17:57   #319
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Default Re: Automatic Transmission v/s Manual

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Originally Posted by jaisonjose View Post
My question is: Can I shift from D to D-4 or 3 or 2 or 1 while the car is moving? I saw few discussions on the same topic but could not conclude.
Yes. That's the only way. D4, D3, D2, D1 is to lock the transmission to that gear.

If you select D3, the transmission will change only 1,2 and 3.

This is useful when going up hill or downhill.
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Old 7th May 2015, 18:38   #320
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Default Re: Automatic Transmission v/s Manual

I believe jaisonjose was asking whether he can shift "while the car is moving". Eg, say he is cruising at 80kmph in D - can he shift to D-4 ?

Well, I have sometimes (during initial days) shifted from D to D-3 on our A-Star. And given that stomping the A-pedal all the way down in an Automatic
anyway results in downshift of gears, I don't think this is wrong or an issue.

So yes, one could manually shift down from D to D-4 to 3 to 2 to 1, but that would take away from the driving-an-AT feeling.
Moreover I love the grunt/scream from the car when I stomp down (though it is mostly all sound and no go, given the puny engine of the A-Star )

Last edited by supremeBaleno : 7th May 2015 at 18:44.
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Old 7th May 2015, 18:50   #321
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Default Re: Automatic Transmission v/s Manual

Quote:
Originally Posted by supremeBaleno View Post
I believe jaisonjose was asking whether he can shift "while the car is moving". Eg, say he is cruising at 80kmph in D - can he shift to D-4 ?
Yup. That's what I mentioned. You can shift to D4, D3, D2 on the move. Anything else would be counter intuitive.

If you suddenly approach a ghat, you obviously shouldn't have to stop and shift to lower gear like D3 and D2.

Same when overtaking. If you are on a single lane road and need to overtake a lorry, the gearbox will be in higher gear and the kickdown lag will be risky when overtaking. In those situations you lock the transmission in D4, D3 and overtake the slower vehicle.
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Old 7th May 2015, 19:16   #322
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Default Re: Automatic Transmission v/s Manual

Yes supremeBaleno. Thatís what my exact question. Mainly when we are doing downhill and if need to get assistance of engine break, do I need to stop the vehicle and then move to D-4 or to the appropriate level.
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Old 8th May 2015, 15:31   #323
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Default Re: Automatic Transmission v/s Manual

Quote:
Originally Posted by ashvtosh View Post
The engine suddenly started touching high rpm's before changing gears. Especially between 1-2-3. It felt that it was making a huge effort to do so. Lots of noise too.
I read somewhere that gear changes also depend on the pressure of Transmission fluid. A change in level or even the quality of transmission fluid can affect the fluid pressure, hence it is best to change the Transmission fluid and check before opting for expensive repairs.
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Old 25th November 2015, 14:40   #324
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Default Re: Automatic Transmission v/s Manual

I was researching around Do Automatic transmission cars rolls back on inclines ? As always , I started searching on Team BHP first for information which helped with answers to few queries, however few some left, so i started browsing and came across a very simple explanation on "How torque converters work".<Link given below>. Please read through, it a nice read and easy to understand.

Link

Last edited by Autolock123 : 25th November 2015 at 14:42. Reason: Text modified
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Old 7th March 2016, 21:57   #325
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Post Re: Automatic Transmission v/s Manual

Hi Guys,

I came across these two videos which I found very informational.

Video courtesy : Respective owners




On a different note:
He had a point when he say "...your brakes are always going to be able to out power your engine." I doubt if that could be 100% true with (all) the cars sold here in India. Manufactures trying, with their last drop of sweat, to give maximum fuel efficiency- we now have cars with thin tires and least kerb weight which works together to give the least amount of traction, add on to that the bad condition of our roads and with people who think themselves Schumacher on their second day behind the wheel, it's no wonder cars often go out of control here in India.
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Old 21st December 2016, 07:20   #326
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Default Re: Automatic Transmission v/s Manual

Moderators - Please move this post to appropriate thread if this is not the right one.

Friends, I have been driving i10 AT (4 speed Torque converter unit) for last 7 years and have clocked close to 20000 kms (mostly city driving). I am now planning to buy a new car and am looking at automatics again - only CVT and Torque Converters units. With kids growing up now, I plan to make more highway trips and planning to keep next car for at least 10 years and clock around 80K to 100K kms.

Reliability - Has anybody in our forum clocked over 100K kms using automatic. People abroad have done it but I was concerned about reliability of automatic transmission in Indian driving conditions. I have been reading various threads and external forums but not much information forth-coming for Indian conditions. The concerns also stems from the fact that in case of break-down (say, pulley belt of CVT), manufacturers prefer to change whole unit costing a bomb instead of just one part, say clutch plate, in case of manual transmission. I have not noticed any higher general maintenance cost for i10AT compared to a manual but am concerned with maintenance cost of transmission unit if something goes wrong.
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Old 21st December 2016, 08:00   #327
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Quote:
Originally Posted by Simhi View Post

Reliability - Has anybody in our forum clocked over 100K kms using automatic.
Not 100k, but 7+ years and 73k kms done in my i10 AT. Touch wood no transmission related issues till now.

I think if properly cared for, AT or CVT boxes can easily do 100k kms. Hesitant to say the same about DCT boxes due to stories heard from VW and Skoda owners. Not much input from Ford DCT owners though.
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Old 21st December 2016, 08:28   #328
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Default Re: Automatic Transmission v/s Manual

I think TCs are the most reliable type of AT. They should easily last as long as MT with proper scheduled maintenance. If you maintain the CVT well by doing scheduled maintenance on time (and everytime), you should not have any problems.

That being said, prior to 2010, I don't know too many cars sold with a CVT in India. You can find information about a Honda City (2nd Gen) in the forum or from any owner.
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Old 21st December 2016, 12:33   #329
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Thumbs up Re: Automatic Transmission v/s Manual

Quote:
Originally Posted by Simhi View Post
Reliability - Has anybody in our forum clocked over 100K kms using automatic
My Civic-AT is nearly ten-years old, has done 1,56,000 kms and auto-transmission is still perfect!

I had a scare only once, a few years back when the Transmission-Warning light was blinking and it would not go above third gear (Civic-AT has 5 gears).
It was solved quickly at HASS, might have been some dust on a sensor since the car was sitting idle for many months prior to that.

I have also done many runs on the Ooty-Mettupalayam hill-roads (which stresses the transmission) many times. A thumbs-up to Honda's engineering!
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Old 21st December 2016, 17:38   #330
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Default Re: Automatic Transmission v/s Manual

Thanks blackasta, landcruiser123 and manim for your inputs.

Quote:
Originally Posted by manim View Post
My Civic-AT is nearly ten-years old, has done 1,56,000 kms and auto-transmission is still perfect!
Nice to hear. I am assuming the auto-transmission was a TC unit and not CVT.
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