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Old 27th February 2009, 00:35   #16
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Originally Posted by vishwaschettri View Post
If you find need for lower gear when in 2nd high you will never be able to shift to 1st high without loosing mommentum.
When moving to lower gears, don't you always lose momentum? Besides, at 4L-1st gear the Jeep will move at snails pace, even if you have synchromesh, how much momentum will be there?

I use 4L-1st very rarely, that too for descents.
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Old 27th February 2009, 00:52   #17
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@ samurai - thanks for formatting my post.
What I meant was switching to 1st high wont be possible without stopping the jeep. Whereas when in 4th low you can easily step down to 3rd low or 2nd low as both are synchromesh and not break the momentum.
I dint mention shifting to 1st low anywhere.
I find 1st low very useful when crawling over huge boulders. You can have all the control and time at your hand and crawl through. Also if the under body takes a hit you are at much lower speed.

cheers
vishwas
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Old 27th February 2009, 01:03   #18
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Tusker4x4:

What is 4Low? Essentially it is a reduction gear.

So the reduction gear of 4Low can be compensated by going to higher gears in the transmission. I can't think of any damage to the engine or axles due to driving in 4L in 4th gear as opposed to 4H and say 1st or second gear.

To give you an example geared bicycles have a larger cog on the pedal and a much smaller cog on the wheel. Now let us say that you replaced the cogs with identical ones on the pedal and the wheel with the same number of gears. Using the lowest gear on the pedal cog and the highest gear on the wheel cog will give you the same power output as doing the reverse.

I would however refrain from trying to pick up too much speed in 4L in 1st and second as the drive train feedback maybe affect the engine.

Just my 2 cents.
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Old 27th February 2009, 01:13   #19
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I too believe that 4H is useless unless you drive in snow/extremely wet mud (not deep slush) conditions. I always use the 4L 5th gear, and i have 4 more gears to fall back if terrain requires. Never used 4H. There was one situation where i tried an obstecle in 4H 1st in place of 4L 3 and 4L 4 but did not yeid any result. But then it depedns on the idividual preferences.

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Old 27th February 2009, 04:23   #20
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Originally Posted by Tusker4x4 View Post
Hey Aman

Harjeev told me that u drove on 4x4 L thru out the OTR. My Advise is use 4x4 only to get through the obstrucle. As soon as u cross the obstacle pls change to 2x4.

4x4 puts a lot of pressure on your engine and also on you gears and shafts. This can create problems in the diffrential and the gearing.

I the track demands 4x4 try high forst if not sucessfull then put Low.

regds

Amit
Hi Amit and all members on this thread.
I am not an expert of this but my opinion according to my experience with my Tata Safari 4x4 is:
The manesar trail quite difficult and I dont think that I should have switched to 4x2 as soon as I cross obstacle because it was full of obstacles and its too difficult to engage and then disengage...
And I dont think that with a electronic 4x4 one should do often switching between 4x2 and 4x4 because it can be stressful for electronic swithing system to switch again and again after every minute..
I was driving in 4x4 L all the time because I was comfortable with it.Normally was driving in 4x4L 2nd or 3rd and on steep climbs in 4x4 L 1st.
I dont think driving in 4x4 (4H or 4L) puts stress on the engine , gearbox , shafts ,etc. because if it puts stress and is harmful then the company wont have offered 4x4 version.
I think 4x4 reduces stress from rear differential , rear shafts because half power is splitted to front.
According to me when you take off in 4x4 H on a climb, more stress is put on the engine rather than 4x4L.
During my whole OTR my safari's radiator fan swithed on only once for 2 mins, else all the time engine was at normal temp. because as soon as it gets hot it switches on radiator fan does it many times driving on highways at 60's.

Please correct me if I am wrong..
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Old 27th February 2009, 04:41   #21
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Some say that if you can run on a track at higher speeds, say, 50-60kph, then you do not need to be in 4wd mode at all. But in snow or slick surface shallow mud, 4wd, 4H, higher gear, helps to keep the front and back end of the vehicle going in the same direction and not be so subject to loosing traction from bumps and ruts at speed. One very dangerous discovery for novice 4wd drivers in N. America who go flying by traffic in the snow and ice is that, yes, you go much better than 2wd vehicles but you don't stop much better. I have seen several turned over or standing in some farmer's field up to their axles in mud.

Behram's suggestion for general purposes on mud surfaces makes a lot of sense to me. But I hope you guys don't take any of this too seriously. Getting stuck is not some cardinal sin and driving out of it can be fun and is a skill set of its own.

If somebody asked me what is the one thing most drivers who make mistakes do I would say not looking down the road far enough, often enough, and thereby not anticipating what they are about to encounter. Then they are surprised and do not have time to react properly to what they are facing.

Last edited by DirtyDan : 27th February 2009 at 04:42.
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Old 27th February 2009, 06:12   #22
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Quote:
Originally Posted by vishwaschettri View Post
What I meant was switching to 1st high wont be possible without stopping the jeep. Whereas when in 4th low you can easily step down to 3rd low or 2nd low as both are synchromesh and not break the momentum. I dint mention shifting to 1st low anywhere.
Oops, I thought you were talking 4H. Ok, in that case we are in agreement.

Quote:
Originally Posted by vishwaschettri View Post
I find 1st low very useful when crawling over huge boulders. You can have all the control and time at your hand and crawl through. Also if the under body takes a hit you are at much lower speed.
I agree, however since the CJ340 has 5.38 axle ratio, it is incredibly slow in 1st low, hence the rare usage. In Munnar I did use it once to negotiate the ancient village street in very slow speed.

Munnar OTR General reports-jt51.jpg
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Old 27th February 2009, 08:18   #23
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DRIVING IN 4WD

There is a lot of myth and misunderstandings that go with the Indian aversion to driving in 4WD i.e. with the 4x4 drive system engaged.

Why shouldn't you drive in 4WD when your vehicle has a 4 WD system in it, it is there for you to negotiate tricky terrain, but the general syndrome is it is some kind of a monster, you must disengage as soon as an obtacle like some soft sand or a mud pool has been crossed.


Over the last twelve years, even for my city and highway driving I have used a Toyota Landcruiser Prado or Landcruiser 100 VXR. These vehicles were full time 4WD, i.e. even in the city on tarmac I was always driving in 4 WD. The system is equipped to handle this vehicle in 4WD all the time.

While off road in the sand, when I used to drive the LWB Prado A/T i drove it mostly in 4 High range.

But when I switched to the SWB Manual Prado I found it drives best in the low range in L4 and L3. The L3 in the M/T Prado was 1:2.178, slightly better than the 2nd gear ratio of 1:2.063. THe transfer case was x2.55

Similarly most Jeeps ( Wranglers ), M/T Landrovers, Toyota 70 series trucks drive best in Low 3 or Low 4.

On tarmac it is perfectly OK to drive in 4 WD, High range, except that any diff lock should not be engaged.

In India the myth is that the 4 WD should be disengaged asap because it consumes double the fuel. No this is not true. You can continue to drive in 4 WD througout your off road trip. It is true that because of more rolling parts there will be a higher strain on the drivetrain system, but you are not consuming more that 8 to 10 % extra fuel in your Jeeps if you have the 4 x 4 high engaged.

In the Indian situation, use of 4x4 low range is hardly warranted unless it is a very deep downhill descent or the vehicle is stuck and a heavy load is being carried. If stuck in sand or mud, use of low range 4x4 will spin the wheels too much so that it will dig deeper in the mud / sand.

Even if used, it is better to use 2nd gear in low range, that should meet the case.

If any one has more queries on any aspect of 4x4 driving, please post your query here.

Best regards,

Shahid Ahmad
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Old 27th February 2009, 08:21   #24
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Quote:
Originally Posted by vinod_nookala View Post
BTW iam not aware of the fact that usage of 4wd create differential and the gearing?...well i dont think so.
Vinod, can you explain the above..i didnt get you.

And BTW, you were amazing in Palar in the way you handled your 540! Still have visuals running in my mind.


Quote:
Originally Posted by Tusker4x4 View Post
The skill lies in sellecting the right gear for the right terrain/obstracle. When a 4x4 is not required why engage it. Using 4x4 low and then starting and driving at 3 or 4 gear is matter of convinence not a matter of skill.
Quote:
Originally Posted by willys MB View Post
I totally agree that use of the correct gear / 4x4/ low/high and reasonable use of power comes only with experience and handling of your 4x4.
+1 to that!

Quote:
Originally Posted by Tusker4x4 View Post
I myself drive a MM540 i think thats about 45 or 48 BHp but again high torque.
Amit, a MM540 with the Peugeot 2.1 engine is 62BHP..unless I got it wrong!
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Old 27th February 2009, 08:26   #25
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TO add further - in a nutshell there is no harm in driving on tarmac ( terra firma ) with high range 4x4 engaged. My travel log shows I have driven about 401,000 odd kilometers on tarmac with full time 4 WD om my Landcruisers and prados.

But when it comes to low range 4x4, disengage before hitting hard ground, shift back to the 4 Hi range.

When in Low 1st never drive your vehicle above 8 km/h speed and in L2 stay below 25 km/h.
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Old 27th February 2009, 10:50   #26
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Quote:
Originally Posted by desertfox View Post
TO add further - in a nutshell there is no harm in driving on tarmac ( terra firma ) with high range 4x4 engaged. My travel log shows I have driven about 401,000 odd kilometers on tarmac with full time 4 WD om my Landcruisers and prados.

But when it comes to low range 4x4, disengage before hitting hard ground, shift back to the 4 Hi range.

When in Low 1st never drive your vehicle above 8 km/h speed and in L2 stay below 25 km/h.
Why dont you try driving a part time 4x4 like the MM540 in 4H all the time? You will give good business to mahindra spares dealers and tyre shops. And braking on slick ice will be even more interesting.
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Old 27th February 2009, 10:57   #27
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You good folks do realize that what works for a Gypsy / MM may not necessarily work for a Safari, right? 4L gives you the *feeling* of much better control especially over the OTR trails our Gypsy & MM owners are fond of. Lesser usage of the clutch & brakes - remember this is a 2.25 ton SUV that can very easily go hurtling into the smaller vehicle in front / back on an OTR trail.
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Old 27th February 2009, 10:59   #28
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Quote:
Vinod, can you explain the above..i didnt get you.

And BTW, you were amazing in Palar in the way you handled your 540! Still have visuals running in my mind.
Hey thank you headers!! I infact couldnt believe that a MM540 could keep pace with Gypsy king and Mahindra Classics and clear obstacles! I think it was a combination of right gearing selection and momentum and above all team work!!!:-)))) (btw I was saying that use of 4wd doesn ot put strain on mechanical components!!)

I wish i could get a copy of some wonderful palar videos taken by my now missing Navigator & his wife!!

Quote:
TO add further - in a nutshell there is no harm in driving on tarmac ( terra firma ) with high range 4x4 engaged. My travel log shows I have driven about 401,000 odd kilometers on tarmac with full time 4 WD om my Landcruisers and prados.

But when it comes to low range 4x4, disengage before hitting hard ground, shift back to the 4 Hi range.

When in Low 1st never drive your vehicle above 8 km/h speed and in L2 stay below 25 km/h.
Dessert fox,

I agree with what you said, but this is true with permanent 4wd vehicles. These vehicles have a central differentail. This doesnot allow for a system windup. However for Indian jeeps and other SUV's (except Vitara & Forester) ONE SHOULD NEVER DRIVE THE WITH 4WD ON HARD SURFACES i.e on TARMAC!!
In my previous jeep when in hyderabad the system accidentally slipped into 4wd without engaging it to 4wd high mode. I didnt notice it. Drove it all round the city like that. AT the end the system build up was so much that engine started heating and vehicle didnt move an inch, neither front nor back! Had to remove the rear shaft tow it to work shop to find that the rear diff gears were compeletely chewed! This can happen to any part time 4wd!!

now few points from me-
1. As aman said in 4wd actually the torque is split between front & rear axles and hence load on each axle is lower. Hence lesser wear!

2. In 4wd low the stress on the engine is lower as the engine is not lugging! Trail driving which we stay at about 20-40 kmph 4 low 4th gear is sufficient. However constant high RPM driving in streneous in 4 low. Assessing the terrain is important. 4wd high is good for trail, loose gravel, snow driving!

3. 4wd H can be good for high powered engines in sandy conditions. Gypsy King does wonderfully in 4wd high on sand. Where as its lower powered cousin 1.0 l engine needs 4wd low to maintain the momentum. Engine power is the key on sand!

regards
vinod
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Old 27th February 2009, 11:00   #29
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Even though I drive a 140BHP "beat" wherever the terrain is such that there is possiblity of getting stuck, I shift to 4L
The reason is that I want to preserve the clutch.
For example when stuck in sand, 4H will get me out, but in initial start some clutch slippage will be required. However in 4L, I can get out in idle!
For not so deep sand where some speed is possible, I use 4H.

For example in Jaisalmer, at Kuldhara ruins, the track was sandy and very narrow, so speed was not possible, moreover due to stuck vehicle, I knew I would have to stop. So I did the stretch in 4L.
So even when reversing 50 meters slowly, 4L was the best for control.
In 4H the speed would have been too high to afford proper control, and I would have had to slip the clutch, something which I hate doing.

Last edited by tsk1979 : 27th February 2009 at 11:01.
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Old 27th February 2009, 11:45   #30
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Quote:
Originally Posted by headers View Post
... Amit, a MM540 with the Peugeot 2.1 engine is 62BHP..unless I got it wrong!
Dear Header,

You are very right about the 2.1 L Peugeot engine. I am not to good at the technical details of the engines. But sure have picked up quite a lot about offroad driving.

Redgs

Amit

Quote:
Originally Posted by desertfox View Post
TO add further - in a nutshell there is no harm in driving on tarmac ( terra firma ) with high range 4x4 engaged. My travel log shows I have driven about 401,000 odd kilometers on tarmac with full time 4 WD om my Landcruisers and prados.

But when it comes to low range 4x4, disengage before hitting hard ground, shift back to the 4 Hi range.

When in Low 1st never drive your vehicle above 8 km/h speed and in L2 stay below 25 km/h.
Dear Desertfox,

You are talking about Landcrusiers and Parados. These are by themselves tecnological marvels. But incase of old 540/550/340 it does have an effect.

Regds

Amit

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