Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 16th January 2008, 22:02   #16
Distinguished - BHPian
 
Thad E Ginathom's Avatar
 
Join Date: Jun 2007
Location: Chennai
Posts: 7,847
Thanked: 7,246 Times
Default

Quote:
Originally Posted by BaCkSeAtDrIVeR View Post
Oh. yes; it does makes a difference.

When the vehicle is facing down on an incline, it will have a tendency to move forward. If the 1st gear is engaged, the engine too will turn, and the vehicle will move. But if the reverse is engaged, the engine will prevent the vehicle from moving since it will (ought to) have a mechanism to prevent it from turning in the opposite direction.
This is not the case: it is simply that rolling from stop, in case of a handbreak failure, has insufficient impetus to overcome the compression of the engine. Reverse and first are the lowest (of course...) gears, in which, with the car driving the engine, it has to turn the engine further for each inch travelled, thus having to work harder. It does not matter which way the car is facing, or which gear you choose. Try it out!

Consider the work required to push-start a car; usually the initial attempts simply result in the engine stopping the car. Only when sufficient speed and impetus is built up will the car turn the engine over sufficiently to start it.

I always park and leave the car in neutral, except on a steep slope. Then I choose 1st or Reverse according to which will do least damage in the unlikely event of my forgetting my usual start-up routine of putting my foot on the clutch.

Your first exercise in a British driving test is that the examiner will see that you check the gear is in neutral. Usually I am the only driver of my cars, and I know I left it in neutral, except on those slopes.

Turning the wheels is good if you parked by a curb. Putting a stone behind the wheel, truck-style is good too!
Thad E Ginathom is offline   Reply With Quote
Old 16th January 2008, 22:28   #17
BHPian
 
hrman's Avatar
 
Join Date: Jun 2006
Location: Bangalore
Posts: 915
Thanked: 361 Times
Default

I park in Neutral all the time. But the hand brakes will be engaged.
As about an inline, well, haven't really parked on an incline. Thats my worst fear..
I also keep the clutch depressed when starting the car. A habit carried forward from the Indica days when I was told that a diesel car needs to be started with the clutch depressed. Its good for the car.
To date, I don't know the advantage of this practice, except that if the car is parked in gear and you forget to change it to neutral while starting, the car will not move forward, jerk and stop.
Any threads on this? I couldn't find any..
And oh yes. My starter motor of my NHC conked off despite following this practice. So im sure, that does not help the life of starter motor. Is there any correlation? I dont know.

Last edited by hrman : 16th January 2008 at 22:31.
hrman is offline   Reply With Quote
Old 16th January 2008, 22:44   #18
Senior - BHPian
 
Join Date: Dec 2007
Location: Dubai
Posts: 3,860
Thanked: 128 Times
Default

Quote:
Originally Posted by hrman View Post
... To date, I don't know the advantage of this practice, except that if the car is parked in gear and you forget to change it to neutral while starting, the car will not move forward, jerk and stop.
Quite obvious mate. If the vehicle is in gear and you do not close the clutch when starting this is bound to happen. Happens to all geared vehicles, period.

I still do not see how the life of the starter motor or load on engine is affected by closing the clutch on starting. Why not simply start in neutral? I do that. Before starting I make sure I am in neutral and then only start.
HappyWheels is offline   Reply With Quote
Old 16th January 2008, 22:50   #19
Distinguished - BHPian
 
Thad E Ginathom's Avatar
 
Join Date: Jun 2007
Location: Chennai
Posts: 7,847
Thanked: 7,246 Times
Default

Thad's Dad's Teachings (he was driving god-only knows how many decades ago, pre-1930s)...

Not having to drive part of the gear box takes some of the weight off the starter motor. Maybe this helped back in the days when people like my father regular gave up on the starter motor and got the starting handle out instead! I don't know if it is really true now, but I still do it.
Thad E Ginathom is offline   Reply With Quote
Old 16th January 2008, 23:06   #20
Senior - BHPian
 
nitrous's Avatar
 
Join Date: May 2004
Location: UAE/Lon/Madras
Posts: 6,966
Thanked: 282 Times
Default

Quote:
Originally Posted by thad
Not having to drive part of the gear box takes some of the weight off the starter motor.
It stands correct even in today's cars.
I can hear my clutch release bearing even in the neutral when the engine's running.
Fact: The Verna CRDI doesn't start without the clutch engaged.
nitrous is offline   Reply With Quote
Old 16th January 2008, 23:14   #21
Team-BHP Support
 
Rehaan's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 22,381
Thanked: 22,606 Times
Default

Quote:
Originally Posted by gd1418 View Post
Now, what I've not understood is how by depressing clutch the load on battery/starter is lessened and is a good practice in comparison to starting the vehicle in neutral?
Well gd1418, put simply, when you press/disengage the clutch there is less mass attached to the parts that the starter motor has to begin to rotate. And if you know, starting is always the hardest part which takes the most torque/amps. (If you notice when your AC compressor comes on at home sometimes the lights dim / flicker for a second, thats because the motor that runs the compressor has a second winding that comes on just for a second to get the required starting torque.)

Quote:
Originally Posted by rks View Post
As per my manual, the gear should only be engaged when the engine is running (I think this will ensure proper lubrication); it is OK to go to neutral before starting your car.
Well that doesnt mean you cannot park your car in gear, it just means that the gear is more likely to slot easily when one or more of the parts are rotating (ie engine on / car moving / lubrication being freshly thrown around). They probably mention this in the manual so that people dont complain that the car is not going into gear when it is off.


Quote:
load on the gears
Quote:
load on the gears
Quote:
load on the gears
Well i personally think this is quite a bad reason / myth.
Think about it this way - Simply put, a car parked in gear on a 40degree incline will be experiencing less than half the weight of the car as "load" on the gears.
Now think about the same car starting to drive uphill. Thats - the cars weight x acceleration as "load". Thats WAY more of a "load", but noone seems to say thats bad.
Gears are strong. I dont think they care about the static load of a car on a small incline, but ofcourse, if you want to release the load from the gears, by all means engage the handbrake first. (Personally i try to even out the load).

cya
R
Rehaan is offline   Reply With Quote
Old 16th January 2008, 23:58   #22
Senior - BHPian
 
vikram_d's Avatar
 
Join Date: Jul 2006
Location: Bangalore
Posts: 2,380
Thanked: 936 Times
Default

I always park in first or reverse depending on slope and in first on flat ground. Hand brake is only used on slopes and not on level ground.
vikram_d is offline   Reply With Quote
Old 17th January 2008, 00:07   #23
Distinguished - BHPian
 
Thad E Ginathom's Avatar
 
Join Date: Jun 2007
Location: Chennai
Posts: 7,847
Thanked: 7,246 Times
Default

You mean you don't use the handbrake?

Otherwise known, (especially by our American cousins. I think?) as the parking brake...
Thad E Ginathom is offline   Reply With Quote
Old 17th January 2008, 09:47   #24
Senior - BHPian
 
Join Date: Dec 2007
Location: Dubai
Posts: 3,860
Thanked: 128 Times
Default

Quote:
Originally Posted by vikram_d View Post
I always park in first or reverse depending on slope and in first on flat ground. Hand brake is only used on slopes and not on level ground.
vikram, this is not all that good for the gear lever. it will be under constant strain.

please use the hand brake; putting it in gear is just a fail-safe measure.
HappyWheels is offline   Reply With Quote
Old 17th January 2008, 09:57   #25
Senior - BHPian
 
Join Date: May 2007
Location: Bangalore
Posts: 3,652
Thanked: 244 Times
Default

Always in gear and handbrake is in use when parked.

Last edited by dadu : 17th January 2008 at 09:58.
dadu is offline   Reply With Quote
Old 17th January 2008, 14:24   #26
BHPian
 
deetee's Avatar
 
Join Date: Oct 2007
Location: Hyderabad
Posts: 244
Thanked: 153 Times
Default

Quote:
Originally Posted by HappyWheels View Post
vikram, this is not all that good for the gear lever. it will be under constant strain.

please use the hand brake; putting it in gear is just a fail-safe measure.
I second that. Engage Handbrake first, make sure it works and use first /reverse gear as a fail safe measure. however i do that on inclines only, on flat surfaces i use hand brake only.
One advantage with using handbrake/parkingbrake(name mentions its use) first is that , its only on inclines that you can test and ascertain the capabilities of your hand brake. If your rear brakepads are slightly worn out,those indications doesnot show up on flat surfaces. Only on inclines ,when the weight of car is bearing on them , does rear brakes show their symptoms. So, first engaging handbrake and then slotting appropriate gear is good for many reasons.
deetee is offline   Reply With Quote
Old 17th January 2008, 15:52   #27
Senior - BHPian
 
vikram_d's Avatar
 
Join Date: Jul 2006
Location: Bangalore
Posts: 2,380
Thanked: 936 Times
Default

Have been doing this since the day I started driving and have never had any problems till date. Anyways when the car is stationary the load on the gear is static load and it is much less than when the car is moving.
vikram_d is offline   Reply With Quote
Old 17th January 2008, 21:59   #28
rks
BANNED
 
rks's Avatar
 
Join Date: Nov 2005
Location: ??
Posts: 1,237
Thanked: 8 Times
Default

Quote:
Originally Posted by Rehaan View Post


Well that doesnt mean you cannot park your car in gear, it just means that the gear is more likely to slot easily when one or more of the parts are rotating (ie engine on / car moving / lubrication being freshly thrown around). They probably mention this in the manual so that people dont complain that the car is not going into gear when it is off.
I checked my manual and what it actually says is to run the engine for 10-20 secs after starting in neutral before engaging gear. I assume this is due to lubrication requirement. I didn't say that the car cannot be parked in gear for this reason (provided handbrake is also engaged), my doubt was whether the gear should be engaged (to first/reverse) before switching off the engine. This may not be all that important, as the lubrication will be fine just after switching off as well. One could presumably shift to the appropriate gear (first/reverse) from neutral immediately after switching off. However, I think it is not a good idea to shift/engage gears a long time after the car has been stopped as then the gearbox oil would have settled down.

Quote:
Originally Posted by Rehaan
Well i personally think this is quite a bad reason / myth.
Think about it this way - Simply put, a car parked in gear on a 40degree incline will be experiencing less than half the weight of the car as "load" on the gears.
Now think about the same car starting to drive uphill. Thats - the cars weight x acceleration as "load". Thats WAY more of a "load", but noone seems to say thats bad.
Gears are strong. I dont think they care about the static load of a car on a small incline, but ofcourse, if you want to release the load from the gears, by all means engage the handbrake first. (Personally i try to even out the load).
After some googling, I found many different opinions on this. But it appears that keeping the load fully on the handbrake is the safest option, for the following reasons.

Firstly, we can then be sure that the handbrake will hold the car still even if the gear slips.

Secondly, it appears that if the gear does slip (in case of manual transmission cars) or if the pawl holding the car breaks (in case of automatic transmission cars put in "Park"), then transmission damage could result as the car moves. Or consider that some other car nudges your car when it is parked on gear (say, when that car tries to squeeze into or out of a parking slot), then damage to the transmission could result if handbrake is not engaged and your car moves.

Here is the relevant website in case of automatic transmission:

Parking pawl - Wikipedia, the free encyclopedia

Quote:
Most manufacturers and mechanics do not recommend using the transmission's parking pawl as the sole means of securing a parked car, instead recommending it should be used as a backup for the car's parking brake. Constant use of the parking pawl only, especially when parking on an incline, means that driveline components are kept constantly under stress, and can cause wear and eventual failure of the parking pawl. Replacement can be an expensive operation since it generally requires removing the transmission from the car.

Last edited by rks : 17th January 2008 at 22:08.
rks is offline   Reply With Quote
Old 17th January 2008, 22:11   #29
rks
BANNED
 
rks's Avatar
 
Join Date: Nov 2005
Location: ??
Posts: 1,237
Thanked: 8 Times
Default

Quote:
Originally Posted by snaronikar View Post
The authorised service centre guy (Maruti) informed that its the other way round.
Actually I don't think there will be much harm even if you switch off the car in neutral and then shift to first or reverse, as the Maruti guy advised you. The lubrication should be just fine immediately after stopping, as I pointed out in my reply to Rehaan. I think one should avoid engaging gears a long time after the car has been stopped, though.

Last edited by rks : 17th January 2008 at 22:14.
rks is offline   Reply With Quote
Old 17th January 2008, 23:30   #30
BHPian
 
kryptik83's Avatar
 
Join Date: Mar 2007
Location: Calcutta
Posts: 34
Thanked: 0 Times
Default

Quote:
Originally Posted by rks View Post
Actually I don't think there will be much harm even if you switch off the car in neutral and then shift to first or reverse, as the Maruti guy advised you. The lubrication should be just fine immediately after stopping, as I pointed out in my reply to Rehaan. I think one should avoid engaging gears a long time after the car has been stopped, though.
yeah exactly what I do while parking. and since I do it most of the time on a slope, it would be mostly in 1st gear as well as handbrakes engaged
kryptik83 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Engine shuts off in neutral gear 2cents Technical Stuff 24 25th September 2013 20:44
AC Switch OFF or Blower Switch OFF Peter Technical Stuff 24 29th June 2011 12:02
Santro gear shifts suddenly into neutral nura Technical Stuff 18 11th August 2008 14:21
Gear slipping to neutral? - Wagon R johy Technical Stuff 32 25th March 2008 19:01
Re: Gear "jumping" to neutral??? johy Technical Stuff 9 9th November 2006 21:45


All times are GMT +5.5. The time now is 06:48.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks