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Old 17th May 2011, 12:20   #1
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Default Emergency driving - Without clutch

A recent thread where a TBHP member was stranded thirty kms from nearest city due to failure of clutch cylinder started some discussion about driving vehicle without clutch. The young children and heat made this breakdown even more miserable.

This thread will attempt to lay down some guidelines for members to follow so that they can rescue themselves from breakdowns like this. Other may also contribute their knowledge and experiences.

First the fundamental of why the clutch?
Broadly clutch is a mechanical part that connects power (engine) on one side and load (transmission) on the other. If life was simple we could have a direct linkage of wheels with engine and need of transmission would be avoided - though not of clutch. So for the moment lets just imagine a car without gear box and clutch.

Now to move this car we can either push this car in gear or use starter to push start the car with jerks coming from engine. Once engine starts up we could then adjust speed by just controlling the accelerator. However this has a problem that whenever such a car come to stop the engine would also stop since wheels and engine are directly linked.

So to over come this problem we use a clutch. A simple friction device that engages and disengages the engine from wheels. This way we can start the engine with clutch disengaged or in open position. The vehicle will remain stationary and only when we engage the clutch the power will be transmitted to the wheels. Or before stopping we could disengage the clutch so that we can stop without engine also jerking to stop.

Step One

EXPERIMENT - try stopping your car while in gear completely without pressing clutch. Yes, you can do this one or twice without causing irreversible harm to your car. Remember that is what happened when you learnt driving first time.

SECOND EXPERIMENT : Without starting engine put your car in first gear. Do not press clutch. Use starter. The engine will give some jerks but youd have your car moving off in first gear. Again this is not something to be done regularly but you should be able to do it if needed.

Of course watch out that you do such experiments in an area that is not congested.

Report in your observations and we will go to step two.
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Old 17th May 2011, 12:45   #2
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Default Re: Emergency driving - Without clutch

Nice topic sudevji,

Coming to SECOND EXPERIMENT.

I have tried this, although accidently. We had an esteem some years back. Generally, when i park the car, i engage the hand break, put the car in 1st gear and then get out. Once on returning, i disengaged the hand break, and forgot to put the car in neutral , When i cranked my foot was on the accelerator pedal pressing it. The car jerked just once and it started and kept going. This all just took a second or so. It was funny and fast. I thought to myself, i found a new way to quick start a car. But was advised not to by mechanics that time.

However, i tried the above thing on our TATA ESTATE, it didn`t work. It just kept on jerking but it didn`t start. Also, it drained out the battery. Probably, this thing doesn`t work on diesel engines.
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Old 17th May 2011, 13:29   #3
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Default Re: Emergency driving - Without clutch

@sudev, it's a nice post, but I request you to continue with the same without waiting for anyone reporting their observations. As you rightly said the steps are to be taken only in dire necessity and I don't know if you will have one or two members try them out just so they can observe what happens.

Meanwhile we don't want to lose out on the complete solution.
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Old 17th May 2011, 14:28   #4
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Default Re: Emergency driving - Without clutch

Well, I have tried both of Sudev's solutions, on multiple cars, both diesel and petrol, albeit rarely. These do work, but I'm not sure it is always repeatable. Are there any better workarounds?
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Old 17th May 2011, 14:45   #5
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Default Re: Emergency driving - Without clutch

Quote:
Originally Posted by roy_libran View Post
Well, I have tried both of Sudev's solutions, on multiple cars, both diesel and petrol, albeit rarely. These do work, but I'm not sure it is always repeatable. Are there any better workarounds?
Workarounds?!?! I think Sudev asked us to try and report back

Waiting for the next post from Sudev.

But I know i cant start or run my Skoda without clutch. A clutch failure implies having to tow the vehicle.
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Old 17th May 2011, 15:00   #6
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Default Re: Emergency driving - Without clutch

Quote:
Originally Posted by sudev View Post
SECOND EXPERIMENT : Without starting engine put your car in first gear. Do not press clutch. Use starter. The engine will give some jerks but youd have your car moving off in first gear. Again this is not something to be done regularly but you should be able to do it if needed.

Of course watch out that you do such experiments in an area that is not congested.

Report in your observations and we will go to step two.
Some caution to this is that dont overdo it if the engine doesnt crank up and starts moving.

You will burn your starter.

Some people use this to pull their vehicle to the side if they get stranded in the middle of the road in case of engine problem or out of fuel, but have also reported burning their starters.
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Old 17th May 2011, 15:56   #7
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Default Re: Emergency driving - Without clutch

Quote:
Originally Posted by sudev View Post
SECOND EXPERIMENT : Without starting engine put your car in first gear. Do not press clutch. Use starter. The engine will give some jerks but youd have your car moving off in first gear. Again this is not something to be done regularly but you should be able to do it if needed.
Quote:
Originally Posted by dadu View Post
Some caution to this is that dont overdo it if the engine doesnt crank up and starts moving.

You will burn your starter.
If at all you are in a desperate situation to try this, call some helpful men from the neighborhood to assist the starting motor by pushing the vehicle. If you have some assistance, then this technique will work with minimum risk to the starting motor. Some vehicles are designed with really fragile starting motors that IT WILL BURN if you attempt to start it without clutch, and without any help.

Another thing I would suggest, is NEVER attempt this if your vehicle is on an incline, and no help. Starting motor's seldom have enough capacity to pull a ton of weight up a slope.

Quote:
Originally Posted by sudev View Post
Of course watch out that you do such experiments in an area that is not congested.
Yes, perfect!. Please watch out that the areas are not congested, because if you have a torquey CRDi mill under the hood, you will be surprised by the effort the engine makes to NOT stall, which of course will mean - keep on moving.
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Old 17th May 2011, 16:36   #8
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Default Re: Emergency driving - Without clutch

Okay so you have now tried starting and stopping your car without clutch. You experienced the jerky starts and jerky stops.

That is first reason why we have a clutch. We slip the clutch so that jerks from engine are taken out when we start the car. We also disengage the clutch when we stop so that engine does not stalls to a stop with over powering load of braking.

Remember also before we did step one experiments in our discussions the car was a single speed car with no gear box. This was only for sake of simplicity. Obviously all vehicles have gear boxes.

And that is the second reason why we need the clutch.

Sometimes engines with high compressions like the diesels may not be able to crank on starter in first gear. Try push starting while in a gear.
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Old 17th May 2011, 16:52   #9
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Default Re: Emergency driving - Without clutch

A bit of theory again - What happens is when we plant a gear box in the car? Well when ever we change gears we need to free the gear box from the power side by using clutch and then change gears. This operation sounds simple enough. The reason for clutch - same as in experiment #1 earlier - is to prevent engine stalling and to freely allow shifting of gears.

Why gears are needed is a subject for a doctorate thesis quite out of scope this little discourse. Suffice to say they are needed in a most vehicles.

Not only we need a clutch but .....read on.

Now gears are funny circular things with teeth all around.

(And before I get professors of mechanical engineering, who hang around TBHP and especially around threads like these - around my neck let me clarify I am talking of simple gears and I know cars use far more complex gears with horrid sounding names like helix and such.....)

The problem is that to slot one gear on to another you need to align all the teeth in a position where they can slide in to each other - or "mesh" with each other. If gears are running (oh okay rotating) at differing speeds it becomes impossible to mesh them. You have to use brute force to slide them over each other. Recall hearing "gnashing" sounds coming from gear box or buses and truck when they try putting first of reverse gear??

A NOT TO BE DONE EXPERIMENT:

While you car is moving forward - very gingerly and slowly - try engaging the reverse gear. You will hear lots of grinding noise. DO NOT SLOT THE GEAR AND DO NOT leave the clutch from depressed position while trying this.

Trust me and take my word - a hint to wise and all that - that you do not want to do this. OR you can if you wish for sake of your personal learning curve actually try this. Although I would not recommend it at at all unless you are prepared to junk your vehicle or are really cool dude who really wants to knows his stuff.

What was happening? The gear teeth rotating in opposite direction relative to each other (or may be one set was stationary) were not in synchronisation with each other and so the grinding noise till you slotted them some how.

So in addition to clutch we need some thing that can line up (or align) gears in a jiffy. So that they slot in to each other easier. That is the job done by "syncromesh rings" that are present in gear box with each gear. They help slow down or synchronise the speed of two gears before they are slotted. In a way synchro mesh rings are miniature clutches.

So a vehicle with syncromesh gears allows you to shift gears without grinding noise and struggle. So which vehicles are these??

Ahhhh time for a progress report check....how many of you did try not to be done experiment? Do we have majority of chickens or cool dudes here. I did. This afternoon.

Last edited by sudev : 17th May 2011 at 16:56.
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Old 17th May 2011, 17:33   #10
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Default Re: Emergency driving - Without clutch

Quote:
Originally Posted by sudev View Post

Ahhhh time for a progress report check....how many of you did try not to be done experiment? Do we have majority of chickens or cool dudes here. I did. This afternoon.
Planning to sell your GV, eh?
All modern cars have forward 5 gears synchromesh, and reverse non synchromesh.
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Old 17th May 2011, 17:59   #11
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Default

So a vehicle with syncromesh gears allows you to shift gears without grinding noise and struggle. So which vehicles are these??

Answer - almost all vehicle with manual gear boxes have syncro rings in all gears. Some do not provide synchro rings with first gear. Reverse gears also do not have synchro rings. You do not want ease of slotting reverse gear while moving forward do you?

Now that we know the theory - in my cockeyed view of affairs mechanical - lets us move to putting this to practise and come straight away - thank god at last - to the thread topic.

Changing gears without using clutch.

Quote:
Originally Posted by tsk1979 View Post
Planning to sell your GV, eh?
LOL. Not yet. Its going strong.

Quote:
All modern cars have forward 5 gears synchromesh, and reverse non synchromesh.
Yes that is why I could not say try engaging the first gear without coming to halt. Try that in an old Amby and you'd know that first and reverse were non-synchromesh.

Last edited by GTO : 19th May 2011 at 11:00. Reason: Merging both back-to-back posts
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Old 17th May 2011, 18:16   #12
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Default Re: Emergency driving - Without clutch

Tried this on our Premier Padmini years ago;

Clutch failed only 3rd and 4th gear was active.
5 occupants in car. Kept engine running, 3 got off and pushed car then engaged 3rd gear with jerk while 3 were pushing. 3rd gear engaged and the 3 jumped in the running vehicle. Drove the vehicle from Nasik to Bombay.
This is highly hazardous to human wellbeing. Try at your own risk.
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Old 17th May 2011, 18:19   #13
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Default Re: Emergency driving - Without clutch

Okay so you have a situation where your clutch wire is broken or cylinder is not working. And you need to use you vehicle.

Step one is starting it
Step two is changing gears.

Step one is almost painless. Without starting the car slot the it onto first (or some cars even second) gear. No use pressing the clutch - remember it is not working. (okay okay please be a dummy just this once and think it is not working) Use starter to start car as you would normally. Only you have to give it a long than usual trun of key. The car would heave and jerk a little but you should be soon purring along in first gear and accelerator would give you speed control for a bit.

Caveat : Do this when you are sure no traffic would block you as soon as you start moving.

Now in this position if you just ease off the accelerator a bit and at the same time push the gear lever towards neutral the car would happily come in to neutral. May be you'd have to give a jerk on the accelarator. Try it.

So you can start off and you can stop by first getting your car to go in neutral and then brake. (dummy jee remember it was your clutch that was not working brakes are fine)

Try this a few time and youd be surprised how easy it is. Next step changing gear to second (or third/fourth/fifth...)
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Old 17th May 2011, 18:19   #14
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Default Re: Emergency driving - Without clutch

Please also do explain what happens when the clutch pedal is not pushed in fully or you do a "half-pedal" gear change!

And, are there major differences in clutch plates of Indian cars?
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Old 17th May 2011, 18:34   #15
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Default Re: Emergency driving - Without clutch

@Sudev - Sir thanks for starting this thread on request by fellow BHPians. The step by step guide for dummies is good.

I think once this thread reaches a logical conclusion i would take a print out and keep it in the car along with the owner's manual Don't know when i might have to make use of it. I am not sure i am going to try these experiments in my only car right away.
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