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Old 23rd December 2009, 00:52   #76
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Originally Posted by ranjitss View Post
Some times I have noticed that even after flooring the clutch pedal on my M800 the 1st gear doesn't engage or is very hard to engage. However through experience I have learn't that if I release the clutch and then again press it the first gear engages as normal. My M800 is a 4 speed 2003 model and I believe it to have a synchromesh gear box.

Can the gurus through some light on this.

Have the other M800 owners faced this too?
SAme problem faced by and my car is a 2004 model but it dosent happen in 1st it happens in 2nd.
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Old 23rd December 2009, 09:44   #77
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Originally Posted by ranjitss View Post
Some times I have noticed that even after flooring the clutch pedal on my M800 the 1st gear doesn't engage or is very hard to engage. However through experience I have learn't that if I release the clutch and then again press it the first gear engages as normal. My M800 is a 4 speed 2003 model and I believe it to have a synchromesh gear box.

Can the gurus through some light on this.

Have the other M800 owners faced this too?
Double clutch will work but are you trying to engage first when the car is moving or from standstill.

If car is moving you need to rev match for it to downshift into 1st else it will grind into the first gear slot.

So if your in second and you need to slow down and need to change into 1st but not stop the car, the change from 2nd to 1st requires you to increase the revs then slot into 1st.

Needs practice though.
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Old 23rd December 2009, 14:36   #78
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Originally Posted by navan49 View Post
Some times I have this problem with the reverse gear. Once I leave the clutch little and press the gear it stays in its position.
I too have experienced it on reverse gear.

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Originally Posted by vid6639 View Post
Double clutch will work but are you trying to engage first when the car is moving or from standstill.

If car is moving you need to rev match for it to downshift into 1st else it will grind into the first gear slot.

So if your in second and you need to slow down and need to change into 1st but not stop the car, the change from 2nd to 1st requires you to increase the revs then slot into 1st.

Needs practice though.

I had experienced this while slowing down on bumps as well as while starting from stand still position. I will be more observant while negotiating a bump. Though it happens only sometimes I have got used to double clutching while starting from standstill.
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Old 23rd December 2009, 16:04   #79
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Originally Posted by ranjitss View Post
I have got used to double clutching while starting from standstill.
But why do you need to double clutch when starting from standstill? Even if you don't have synchro on the first gear? It is just pressing the clutch and shifting from neutral to first right?
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Old 23rd December 2009, 17:49   #80
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Originally Posted by ranjitss View Post
Though it happens only sometimes I have got used to double clutching while starting from standstill.
Simply outrageous.
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Old 29th December 2009, 15:41   #81
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Originally Posted by clevermax View Post
But why do you need to double clutch when starting from standstill?
Me too searching for an answer.

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Originally Posted by janitha View Post
Simply outrageous.
Can't help it. The first gear just refuses to engage or is very hard and I have to push with little bit of extra strength. Releasing the clutch and pressing it again makes the shifting into first gear smooth and easy.

I remember even in Premiar Padmini, sloting into first gear was difficult. One of my uncle told me to shift the lever to second gear and then to the first gear while starting from standstill. I was surprised to notice that by doing so the first gear was easy and smooth to engage.
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Old 29th December 2009, 16:05   #82
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Originally Posted by clevermax View Post
But why do you need to double clutch when starting from standstill?
Me too searching for an answer.

Quote:
Originally Posted by janitha View Post
Simply outrageous.
Can't help it. The first gear just refuses to engage or is very hard and I have to push with little bit of extra strength. Releasing the clutch and pressing it again makes the shifting into first gear smooth and easy.

I remember even in Premiar Padmini, sloting into first gear was difficult. One of my uncle told me to shift the lever to second gear and then to the first gear while starting from standstill. I was surprised to notice that by doing so the first gear was easy and smooth to engage.
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Old 4th January 2010, 16:18   #83
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Originally Posted by Ravveendrra View Post
4. Double de-clutching was required only when there was a sticky shift on the offing i.e. the gear lever kinda balked at the thought of moving into another gear, this the driver felt as a resistance in his palm when trying to shift. Double de-clutching was also the method of choice when one had to ensure a fool proof shift eg. on a ghat road or when overtaking at high speed (with a full load) with heavy on coming traffic.
Thanks Ravveendra,
that was a very detailed account! If one of todays car balks at downshifting say from 3rd to 2nd at reasonable speeds like 40 kmph and 2nd to 1st at say 15kmph, perhaps one could sort it out by double clutching. But what part is responsible for the problem with the shift downs?
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Old 6th January 2010, 12:37   #84
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Originally Posted by harsha.cs1 View Post
Thanks Ravveendra,
that was a very detailed account! If one of todays car balks at downshifting say from 3rd to 2nd at reasonable speeds like 40 kmph and 2nd to 1st at say 15kmph, perhaps one could sort it out by double clutching. But what part is responsible for the problem with the shift downs?
The most important thing while downshifting is to match the engine speed to the speed of the wheels. If one is using the engine to brake, the speed will necessarily not match so one has to nudge the gear stick so that the gears engage properly and ease the foot off the clutch so that the engine and transmission do not suffer a heavy jolt.

The 'balking' is not due to any problem or defect. It is natural and will happen unless the gear wheels are perfectly aligned at that particular moment.

Cheers,
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Old 6th January 2010, 12:54   #85
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Double clutch is mainly required in old gen cars and trucks where synchronizes were not available or not effective. Double clutching can also be used during down shifts along with rev-matching to make a smooth transition from higher gears to lower gears.
Rev matching is matching the engine revs of a lower gear when transiting from higher gears. Lower gears rev to a higher RPM to achieve the same speed as achieved by higher gears. So when downshifting at speed X from 4th gear(Y rpm) to 3rd gear Speed X (Z rpm) Z>Y, we need to rev to match the speed of lower gear.
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Old 6th January 2010, 13:19   #86
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Originally Posted by v12 View Post
hey guys, correct me if i'm wrong. Our BEST buses need double clutching, right???
If I remember correctly, the old BEST buses (Single and Double deckers of the same type) were with automatic transmission. No clutch.
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Old 6th January 2010, 13:27   #87
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Originally Posted by ranjitss View Post
Some times I have noticed that even after flooring the clutch pedal on my M800 the 1st gear doesn't engage or is very hard to engage. However through experience I have learn't that if I release the clutch and then again press it the first gear engages as normal. My M800 is a 4 speed 2003 model and I believe it to have a synchromesh gear box.

Can the gurus through some light on this.

Have the other M800 owners faced this too?
I had this problem of the gears (2nd) getting stuck once in a while on my Maruthi 800 (1987). Wear & Tear in the gear selector components were causing it. overhauling the gear box made gear selection very smooth.
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Old 7th May 2010, 16:02   #88
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Default Double dutch:-)

Two different issues here.

@ranjitss. If you are engaging 1st from neutral and need to depress the clutch twice to get gears engaged, then the clutch master cylinder may be developing less hydraulic pressure. If the problem involves shifting beyond 1st to 4th and back to 2nd, it involves the synchro cones action. Also, the problem comes up if the gearbox oil's viscosity is less than desired/it is sludged up/low in quantity.
Best Band Aid remedy: BEFORE going to 1st, get into REVERSE (yes, reverse) and then back to neutral and then to 1st. Action will be a hot knife through butter. Reason: the 1st and reverse gear plates are on the same shaft and the selector engages a counter shaft to "reverse" the rotation of the main shaft.(The original meaning of the "R" on the gearshift knob indicated reversing the main shaft rotation. It helped that this put the vehicle into a motion reverse of forward)

Double de clutching has been discussed adequately. My two cents. It had to be resorted to on account of the absence of synchro mechanisms in earlier cars. It IS the better way of engaging gears even of full synchro ( where one can go to 1st directly from 2nd without coming to neutral in between) gearboxes as the chances of gear teeth hitting gear teeth are minimised and the idler slots smoothly into the selected plate. Try it out, requires little practise and you will never have teeth-setting-on-edge sounds a.k.a a dying gearbox on your car.
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Old 9th May 2010, 07:51   #89
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double de-clutching is an old technique used largely on non synchromesh / semi synchromesh geared cars where especially when one is changing down say while going fast-ish around corners and wishes to shift from 4th to 2nd direct, one depresses the clutch, blips the engine a bit to get the revs up and the gear cogs to move a bit faster so that when engaging second gear the cogs actually bite.
then of course one releases the clutch and accelerates through the curve.
the technique was mostly used while racing/rallying in the old days before synchromesh became refined and more or less the norm in cars.

this is my understanding. i used to use this technique quite a bit in the old fiat and amby and/ or mahindra 540 days in the 80's and 90's while driving about in the hills.

Last edited by shankar.balan : 9th May 2010 at 07:52.
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Old 9th May 2010, 09:46   #90
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Double declutching in Ambys and Fiats was once a nice way to downshift especially in Ambys, because almost in all Ambys shifting to third from fourth used to make some unpleasant noise which could be avoided. I remember doing this for downshifting especially in old steering colums mounted gear shifts.
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