Go Back   Team-BHP > Buckle Up > 4x4 & Off-Roading > 4x4 Technical


Reply
 
Thread Tools Search this Thread
Old 24th August 2010, 14:45   #1
Senior - BHPian
 
The Wolf's Avatar
 
Join Date: Jan 2005
Location: Bangalore
Posts: 1,116
Thanked: 58 Times
Default Using clutch and designing clutch...

Quote:
Originally Posted by Samurai View Post

Jeepers never do half-clutching in offroading
LOL, now you are making the Jeepers sound like Gods!!!

Half clutching is sometimes involuntary when one gets stuck and is trying hard to overcome the obstacle in context. Plus with water/oil entry the clutch fade can be very easily felt. I felt a serious slippage of my diaphragm type clutch after I spent some time in knee deep water+muck however after driving for a few miles things felt better. The oil+water entry might have caused slippage which might have evaporated due to frictional heat after driving a few miles.

EDIT: Moved here from Tejas 4x4 thread since its more relevant here.

Last edited by Jaggu : 24th August 2010 at 18:37.
The Wolf is offline   Reply With Quote
Old 24th August 2010, 16:56   #2
Team-BHP Support
 
Samurai's Avatar
 
Join Date: Jan 2005
Location: B'lore-Manipal
Posts: 22,042
Thanked: 13,483 Times
Default

Quote:
Originally Posted by The Wolf View Post
LOL, now you are making the Jeepers sound like Gods!!!

Half clutching is sometimes involuntary when one gets stuck and is trying hard to overcome the obstacle in context.
Well, I was trained never to touch the clutch except for changing gears while offroading, Arka drills such discipline into all his trainees. I have been religiously following the advice ever since. I don't do half clutching even when I am stuck, I don't see the need.

You on the other hand are very different from rest of us. Since you did a lateral shift from drag racing, you started offroading as an expert. And that is very apparent from your posts.

So please tell us, what is advantage of half-clutching when one is stuck? I might as well learn this new technique if it is useful.
Samurai is offline   Reply With Quote
Old 24th August 2010, 17:40   #3
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,487
Thanked: 6,764 Times
Default

Half clutch especially in an offroad situation can be disastrous for the clutch, most of us try to re-learn our driving and avoid the involuntary instincts. It took a while but yes i have now figured it out.

Last week at Somwarpet when the throttle body was acting funny, either i could have slipped the clutch and get out OR back out and do full rev clutch dump launch, i took the latter approach, otherwise i would have fried the clutch by the time i crossed that cement stream
Jaggu is offline   Reply With Quote
Old 24th August 2010, 17:51   #4
Team-BHP Support
 
tsk1979's Avatar
 
Join Date: Feb 2005
Location: New Delhi
Posts: 22,850
Thanked: 15,406 Times
Default

Even though I do not own a jeep, I have done my fair share of getting stuck. Never, I repeat never, have I needed to do half clutching. I slowly release the clutch when I am bogged down, initially not giving throttle input.
If the vehicle stalls, it means I am in two high a gear.
Then I shift to 1st gear in low ratio. Gently release clutch, wheels start spinning. All throttle input is given with foot not touching clutch.
If you give throttle input while clutch is half pressed, it will be roasted.

Even in non slush stuck scenarios, like this one, where I am rock crawling, I was able to climb this steep slow without any throttle or clutch input. I was in 1st gear low ratio, and the vehicle climbed on idle. Diesels have tremendous low end torque


If we come to a scenario where you get struck, see this video

I was in fine dust type sand, much more difficult and grippy than desert sand.
Attempted to tow out the qualis, but got bogged down.
So after that I drove back and forth, in first gear low ratio to first level out the track enough. I released clutch and then started giving throttle input.
For initial escape, I gave slight revs, quickly left the clutch, and pumped in more revs. After that it was simple idling stuff.

Long time back, when I was in college, we had a gypsy. I knew nothing about offroading, and almost fried the clutch trying to get out of a sand pit on 4H. Shifted to low ratio as realization dawned.
tsk1979 is offline   Reply With Quote
Old 25th August 2010, 00:30   #5
Senior - BHPian
 
The Wolf's Avatar
 
Join Date: Jan 2005
Location: Bangalore
Posts: 1,116
Thanked: 58 Times
Default

Quote:
Originally Posted by Samurai View Post
Well, I was trained never to touch the clutch except for changing gears while offroading, Arka drills such discipline into all his trainees. I have been religiously following the advice ever since. I don't do half clutching even when I am stuck, I don't see the need.

You on the other hand are very different from rest of us. Since you did a lateral shift from drag racing, you started offroading as an expert. And that is very apparent from your posts.

So please tell us, what is advantage of half-clutching when one is stuck? I might as well learn this new technique if it is useful.
LOL, when did I ever say that you, Jaggu or Tejas de-clutch or when did I ever say its a technique one should practice???!!! Whether as an expert or not the logic is simple, sometimes it can be an involuntary reaction to bail yourself out by declutching, atleast mere mortals like me have done it stupidly hence I posed it as a possibility. Whats the big deal here?

Quote:
Originally Posted by Samurai View Post
Since you did a lateral shift from drag racing, you started offroading as an expert. And that is very apparent from your posts.
Thanks mate, appreciate your acknowledgement. It does take a lot of heart to make such comments on open forum, leme give you jaadu ki jhappi come
The Wolf is offline   Reply With Quote
Old 25th August 2010, 08:44   #6
Team-BHP Support
 
Samurai's Avatar
 
Join Date: Jan 2005
Location: B'lore-Manipal
Posts: 22,042
Thanked: 13,483 Times
Default

Quote:
Originally Posted by The Wolf View Post
LOL, when did I ever say that you, Jaggu or Tejas de-clutch or when did I ever say its a technique one should practice???!!!
Nice attempt at wriggling out, but let's revisit your statement. BTW, we are talking about half-clutching, not de-clutching.

Quote:
Originally Posted by The Wolf View Post
Change the clutch. It may be new but sometimes water entry and heavy OTR'ing may prematurely destroy your clutch.
When you tell Tejas that his new clutch may be destroyed due to heavy OTR'ing, there is no other way to interpret it. To destroy the clutch one has to half-clutch regularly, not once or twice. When I said Jeepers don't half-clutch like that, you said they are not gods and they will do it involuntarily. But so many times? Enough times to fry the clutch?

Quote:
Originally Posted by The Wolf View Post
Whether as an expert or not the logic is simple, sometimes it can be an involuntary reaction to bail yourself out by declutching, atleast mere mortals like me have done it stupidly hence I posed it as a possibility. Whats the big deal here?
Any Jeeper worth his salt would have overcome that involuntary reaction after couple of OTRs. And Tejas is no newbie.

Quote:
Originally Posted by The Wolf View Post
Thanks mate, appreciate your acknowledgement. It does take a lot of heart to make such comments on open forum, leme give you jaadu ki jhappi come
Oh, it doesn't need heart, just frustration. Since I am not in Bangalore, let me nominate one of the Bang Bros to receive the Jaadu ki Jhappi on my behalf. Beware, they may not let you go after that, you might get assimilated into the collective, like the Borg.
Samurai is offline   Reply With Quote
Old 25th August 2010, 11:44   #7
Senior - BHPian
 
The Wolf's Avatar
 
Join Date: Jan 2005
Location: Bangalore
Posts: 1,116
Thanked: 58 Times
Default

Quote:
Originally Posted by Samurai View Post
Nice attempt at wriggling out, but let's revisit your statement. BTW, we are talking about half-clutching, not de-clutching.
Wriggling out of what???!!! I stand by what I posed as a possibility, 100% of it, a million more times. LOL

Quote:
Originally Posted by Samurai View Post
When you tell Tejas that his new clutch may be destroyed due to heavy OTR'ing, there is no other way to interpret it. To destroy the clutch one has to half-clutch regularly, not once or twice. When I said Jeepers don't half-clutch like that, you said they are not gods and they will do it involuntarily. But so many times? Enough times to fry the clutch?
Lets get to the fundamentals mate, let me explain- Firstly I didnt receive any official communication from Tejas that this is his new clutch. Secondly, it DOES NOT take SO MANY TIMES of incorrect moves to destroy the clutch, 30secs is enough, even in well dynamically balanced clutch/pressure plate assemblies. These old systems are no where close to being even half as close to a modern cars balanced values. Plus one doesnt need to FRY the clutch completely to face diminished performance. Lets not get into these things, there is a lot and more than I could be interested in typing here. Call me if you want to understand it explicitly.

Quote:
Originally Posted by Samurai View Post
Any Jeeper worth his salt would have overcome that involuntary reaction after couple of OTRs. And Tejas is no newbie.
Again, Jeepers are not Gods. Anyone can make mistakes- me, you, Arka, anyone irrespective of experience or expertise. Dont press on 100% perfection, 100% of time, unless one is a Superman. Sit back and think of all the things that you might have known really well theoretically but wouldve still have faulted while executing during OTRs, you will know what I mean. One such example is your down hill 2nd Low incident in mumbai... Salt and pepper, id like to keep for my eggs this time around, haha!

Quote:
Originally Posted by Samurai View Post
Oh, it doesn't need heart, just frustration. Since I am not in Bangalore, let me nominate one of the Bang Bros to receive the Jaadu ki Jhappi on my behalf. Beware, they may not let you go after that, you might get assimilated into the collective, like the Borg.
"Bring em all, try it all, have seen it all, much more than you can believe but would like to do it one more time if you love it that way"

Last edited by khan_sultan : 26th August 2010 at 10:52. Reason: Please keep it clean.
The Wolf is offline   Reply With Quote
Old 25th August 2010, 12:43   #8
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,487
Thanked: 6,764 Times
Default

Quote:
Originally Posted by The Wolf View Post
Secondly, it DOES NOT take SO MANY TIMES of incorrect moves to destroy the clutch, 30secs is enough, even in well dynamically balanced clutch/pressure plate assemblies. These old systems are no where close to being even half as close to a modern cars balanced values.
On the contrary, "my experience" is these primitive systems have so much of tolerance built into them, that they can take hell lot of abuse compared to a modern design. Case in hand, Gypsy clutch can get fried in minutes, where as jeeps can go on and on.

And who needs clutches, coz we can start in low and still go, on and on and on Me drove DwArF without clutch pedal working for couple of kms inside city, buwahahaha.

Quote:
Originally Posted by The Wolf View Post
Plus one doesnt need to FRY the clutch completely to face diminished performance.
Might be true for a performance, stage 1, 2, 3 kinda clutches. Our 800 bucks stuff can perform more consistently, coz they were designed to take such abuse and ambiguity from the day they were conceived.

Quote:
Originally Posted by The Wolf View Post
Again, Jeepers are not Gods.
But still there are god's amongst jeepers and some disciples too
Jaggu is offline   Reply With Quote
Old 25th August 2010, 13:13   #9
Senior - BHPian
 
The Wolf's Avatar
 
Join Date: Jan 2005
Location: Bangalore
Posts: 1,116
Thanked: 58 Times
Default

Quote:
Originally Posted by Jaggu View Post
On the contrary, "my experience" is these primitive systems have so much of tolerance built into them, that they can take hell lot of abuse compared to a modern design. Case in hand, Gypsy clutch can get fried in minutes, where as jeeps can go on and on.
Its not the design, its the function, high revving engines are more prone to clutch frying. But that again is subjective, performance clutches can take the abuse till several thousand hps at crank. Heard centrifugal clutches?? But thats not the point here. Harmonic imbalances coupled with water/oil/muck contamination plus a couple of incorrect involuntary inputs will catalyze clutch deterioration. The degree if deterioration can be realized only during loaded applications and not while comfortable highway cruising so many times. Not even the best in world jeeper can avoid the circumstantial damage unless the condition is worked around mechanically through better engineering/ingenious ideas.

Quote:
Originally Posted by Jaggu View Post
Might be true for a performance, stage 1, 2, 3 kinda clutches. Our 800 bucks stuff can perform more consistently, coz they were designed to take such abuse and ambiguity from the day they were conceived.
Any scientific basis for the above assumption mate? My definition of clutches that are built to take abuse is very very different from your above deliberation hence asking...

Quote:
Originally Posted by Jaggu View Post
But still there are god's amongst jeepers and some disciples too
Yeah, I can see that

Last edited by The Wolf : 25th August 2010 at 13:21.
The Wolf is offline   Reply With Quote
Old 25th August 2010, 13:19   #10
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,487
Thanked: 6,764 Times
Default

Quote:
Originally Posted by The Wolf View Post
Not even the best in world jeeper can avoid the circumstantial damage unless the condition is worked around mechanically through better engineering/ingenious ideas.
Thats what we do, to make our jeep's run better. Actually our mech's do that for us lol and it aint rocket science.

Part of what you said is true, some contamination cannot be avoided. Like Gogi's CJ that was stuck in water, all it took was some idling and clutch was back. And over 30 mts back to capable offroad performance where, that low revving engine would take us. But i dont think Gogi has replaced the clutch yet and has done couple of hundred's of kms and many OTR's.

Thats all the evidence.

EDIT: And its not HP, its the torque that usually busts the clutches in these primitive vehicles. Hence the original point, learn not to use half clutch, sooner the better.

Quote:
Originally Posted by The Wolf View Post
Any scientific basis for the above assumption mate?
You know me from NDMS thread, no scientific reasons, am an arts guy and all i share is from my experience. Take it, mock it or leave it. Your choice.

Quote:
Originally Posted by The Wolf View Post
Yeah, I can see that
Yes we are open to criticism and humor, unlike

EDIT: Correcting the quote's.

Last edited by Jaggu : 25th August 2010 at 13:23.
Jaggu is offline   (1) Thanks Reply With Quote
Old 25th August 2010, 13:20   #11
Distinguished - BHPian
 
Tejas@perioimpl's Avatar
 
Join Date: Sep 2008
Location: Bombay
Posts: 3,947
Thanked: 4,759 Times
Default

Quote:
Originally Posted by Samurai View Post
Any Jeeper worth his salt would have overcome that involuntary reaction after couple of OTRs.
In my case even if i wanted to even ride the clutch, i wouldn't be able to do so since i'm too constrained for space and the foot bangs in the wiper stalk everytime i depress the clutch. So for me the jeep helped my re-learning curve.

Quote:
Originally Posted by The Wolf View Post
I didnt receive any official communication from Tejas that this is his new clutch.
You should have just gone through the thread. Was mentioned just a few pages back.


Anyways, coming back to the topic, if anyone is inadvertently using the clutch, he should seriously consider relearning his driving skill. It is also dangerous if you are coming down a steep descent.
Jaggu is right, jeep clutches can take tremendous abuse. The gypsy clutch fries very easily.
Tejas@perioimpl is offline   Reply With Quote
Old 25th August 2010, 13:26   #12
Distinguished - BHPian
 
Join Date: Jul 2007
Location: MUMBAI
Posts: 3,059
Thanked: 4,571 Times
Default

Dear all - I completed 27 Great Escapes in MH01P2540, a 1994 model red CJ340 and at 45000 kms, the clutch was original and worked perfectly. I must have pulled out hunderds of vehicles in those 27 Great Escapes. One of our endurance run Scorpios which ran for 1 lakh 25 thousand kilometers in one year had absolutely no issue with the clutch. The same unit was refitted and it completed vehicle life test of 3 lakh 50 thousand kilometers. The life of the car is considered as 3 lakh 50 thousand kilometers.

This reminds me of what my the then boss had told me in 1980 when I was a trainee. He said - "Behram, if used correctly, the life of the clutch must equal the life of the car. If not used correctly, the life of the same clutch is 10 minutes".

You may be a little surprised to read this, but it is true.

Best regards,

Behram Dhabhar
DHABHAR.BEHRAM is offline   (4) Thanks Reply With Quote
Old 25th August 2010, 13:35   #13
Senior - BHPian
 
The Wolf's Avatar
 
Join Date: Jan 2005
Location: Bangalore
Posts: 1,116
Thanked: 58 Times
Default

Quote:
Originally Posted by Tejas@perioimpl
;2041735]In my case even if i wanted to even ride the clutch, i wouldn't be able to do so since i'm too constrained for space and the foot bangs in the wiper stalk everytime i depress the clutch. So for me the jeep helped my re-learning curve.


Quote:
Originally Posted by Tejas@perioimpl
You should have just gone through the thread. Was mentioned just a few pages back.
My bad! My heartfelt apologies...


Quote:
Originally Posted by Tejas@perioimpl
Anyways, coming back to the topic, if anyone is inadvertently using the clutch, he should seriously consider relearning his driving skill. It is also dangerous if you are coming down a steep descent.
Jaggu is right, jeep clutches can take tremendous abuse. The gypsy clutch fries very easily.
Yes, definitely agree...
Put the same jeep clutch in gypsy (not same same but similar material and tolerance) and it will fry its bones brown in no time too coz of higher revvs. But ofcos bad driving and clutch contamination are bigger culprits.

Hey, thinking of the above, do you get performance clutches for jeeps too? I would love to go for one if its I find a straight fit for my mm540.



Quote:
Originally Posted by dhabar.behram
This reminds me of what my the then boss had told me in 1980 when I was a trainee. He said - "Behram, if used correctly, the life of the clutch must equal the life of the car. If not used correctly, the life of the same clutch is 10 minutes".
Well, comes from the horses mouth. I rest my case.

@bblost: Clutch contamination in old vehicles which are used off tarmac especially under water, harmonic imbalances especially in slightly high revving older motors with asbestos based clutch plates, pressure plate clamping force deterioration etc etc etc so many factors mate, dont know where to start and where it will end!!! The same clutch can last 1km or 1lac km, now that is something I have literally experienced first hand hence my deliberation mate....

Last edited by The Wolf : 25th August 2010 at 13:52.
The Wolf is offline   Reply With Quote
Old 25th August 2010, 14:56   #14
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,487
Thanked: 6,764 Times
Default

Quote:
Originally Posted by The Wolf View Post
Put the same jeep clutch in gypsy (not same same but similar material and tolerance) and it will fry its bones brown in no time too coz of higher revvs. But ofcos bad driving and clutch contamination are bigger culprits.
I think you are lil mistaken here, technology as you said has evolved. Same for Jeep's. Nowadays we have much better material being used and hence people upgrade parts like clutch to newer one's. Which will work fine even in a gypsy.

Quote:
Originally Posted by The Wolf View Post
Hey, thinking of the above, do you get performance clutches for jeeps too? I would love to go for one if its I find a straight fit for my mm540.
Easier is to find a matching plate from a modern product from M&M for your 540. IIRC my CJ3B with hurricane runs on a bolero plate assembly.

Quote:
Originally Posted by The Wolf View Post
Well, comes from the horses mouth. I rest my case.
What is your case? That jeep clutches don't last long, especially if abused?

My take, it does last even with contamination, harmonics and cacophony inside the jeep.

Quote:
Originally Posted by The Wolf View Post
Clutch contamination in old vehicles which are used off tarmac especially under water, harmonic imbalances especially in slightly high revving older motors with asbestos based clutch plates, pressure plate clamping force deterioration etc etc etc so many factors mate, dont know where to start and where it will end!!! The same clutch can last 1km or 1lac km, now that is something I have literally experienced first hand hence my deliberation mate....
Oh so you are also moving away from scientific facts to personal observation now?

But do share more details about your research on harmonic balancing etc, we would definitely like to learn the science, as much as possible, with our non scientific brains.
Jaggu is offline   Reply With Quote
Old 25th August 2010, 16:19   #15
Senior - BHPian
 
The Wolf's Avatar
 
Join Date: Jan 2005
Location: Bangalore
Posts: 1,116
Thanked: 58 Times
Default

Quote:
Originally Posted by Jaggu View Post
I think you are lil mistaken here, technology as you said has evolved. Same for Jeep's. Nowadays we have much better material being used and hence people upgrade parts like clutch to newer one's. Which will work fine even in a gypsy.
Did I ever say we are using 1955's clutch today? The technology has definitely gotten better but that wouldnt compensate for grave driver error right or mechanical failures due to worn out+tolerance altering abuses right? If you dont believe so, give me your jeep, I will bust your clutch in 15mins flat, wana take a bet?


Quote:
Originally Posted by Jaggu View Post
Easier is to find a matching plate from a modern product from M&M for your 540. IIRC my CJ3B with hurricane runs on a bolero plate assembly.
I am speaking about a PERFORMANCE clutch. Performance clutches have tolerances set way beyond street and mild off the road. Simply, they can take atleast 25 and max of 200%+ additional load.


Quote:
Originally Posted by Jaggu View Post
What is your case? That jeep clutches don't last long, especially if abused?
Dont patronize me dude. NO clutch can take abuse without any inherent deterioration, your definition/degree of abuse might vary from mine. Its not about a Jeep or peep in this case. God, Im running out of words, give me better vocabulary . I cant believe you smashing the dead horse open even after reading BD sirs last post, which is sooo conclusive!!!

Quote:
Originally Posted by Jaggu View Post
Oh so you are also moving away from scientific facts to personal observation now?

But do share more details about your research on harmonic balancing etc, we would definitely like to learn the science, as much as possible, with our non scientific brains.
I wouldnt have tried so hard if I hadnt cared. Lets be open, civil, scientific and mature

Last edited by khan_sultan : 26th August 2010 at 10:56. Reason: Please keep it clean.
The Wolf 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
Best Automobile designing institutes? theragingbull Shifting gears 2 18th March 2014 01:11
Designing a Home Theatre System Samurai Gadgets, Computers & Software 47 26th February 2014 12:56
Designing a new website married2speed Gadgets, Computers & Software 170 18th December 2012 10:16
Automobile Designing Software??? Sid Schumacher Gadgets, Computers & Software 10 31st August 2011 08:59
Could people be interested in designing their own track? As a fun exercise? 1Day Int'l Motorsport 5 17th June 2007 23:23


All times are GMT +5.5. The time now is 07:33.

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