[Samurai]

Originally Posted by U.B.Singh

Once you put the 3 inches wider MM540 axles, your 340 get the specs of the Mahindra Classic. Rest is all well known to Classic owners, about stress, stability, strength etc.
Go ahead and simply swap the differentials for wider track. If possible try and source them off a MM550, you will get disc brakes in front and limited slip rear crown/tail assy.

UBS Sir, do you mean I can switch to MM540 axle/diffs/housing without worrying about any side effects? Then why are people suggesting changing my suspension setup (new leafs or shocks)...

Also, did you mean Classic has the same axles as MM540?

[RedMM340]

Originally Posted by Samurai

That was my first thought, but one has to consider the cantilever stress on the bolts.

I run alloys with numerically low offset AND 1.25 inch spacers with no problems.

The D44 is a tough axle and the 340 is a very light vehicle, so there should be no problems.

[Cyrus43]

Hello all - Behram Dhabhar here, I am replying from Cyrus's login. At first sight, please note that CL340 axle has a track width of 48" whereas MM540 has a track width of 51". The NGCS MM540 has a track width of 53". WHICH AXLE YOU WANT TO PUT WHERE? Please be clear what you want to do, don't waste time effort and money for nothing. I will give all details shortly.

Best regards,

Behram Dhabhar

[Samurai]

Behram, generally I don't make any changes unless I understand all the pros and cons. I am however curious of the following statement by UBS.

Once you put the 3 inches wider MM540 axles, your 340 get the specs of the Mahindra Classic.

Does that mean CJ340 has a shorter axle than CL340?

[nitrous]

OT:

Originally Posted by jyobeb

Of course, the fact that you had disc brakes made a massive difference too. Till I fixed discs on my old jeep, I used to have a scare every time I used it after a couple of days break! The damn thing would suddenly swerve on applying brakes.

Yeah,drums are not at all progressive!

[amit V8]

a bit , but if a coil spring is added with a leaf how much does it help?? as far as i know leaf springs don't fold much.
please see the picture.

[DirtyDan]

Originally Posted by amit V8

a bit , but if a coil spring is added with a leaf how much does it help?? as far as i know leaf springs don't fold much.
please see the picture.

Amit, I do not think this is a spring, this red thing. It is the rubber boot that fits over shock absorbers of some brands.

[DHABHAR.BEHRAM]

Dear Sharat - the axle track of CJ340, CL340 and CL340 classic is same (wheel track within 24 mm due to minor difference in wheel rim offsets on model specifications). How can it be majorly different, body envelope is same tyre will foul all over the place if it is changed, even spring seat and shock absorber mountings are different. However CJ340 and CL340 have 5.38:1 (43/8) axle ratio whereas CL340 classic has 4.88:1 (44/9) axle ratio. 5.38:1 is still the best for offroading that's why the CL340 goes effortlessly over obstacles when other vehicles struggle. I hope people will get clarity soon.

In India, there seem to be a dime a dozen establishments just waiting to sell you anything and take your money. Many have burnt their fingers. Please be careful.

Best regards,

Behram Dhabhar

[khan_sultan]

Originally Posted by DHABHAR.BEHRAM

...... However CJ340 and CL340 have 5.38:1 (43/8) axle ratio whereas CL340 classic has 4.88:1 (44/9) axle ratio. 5.38:1 is still the best for offroading that's why the CL340 goes effortlessly over obstacles when other vehicles struggle.....

Behram, from your post I am assuming that the transmission ratio & the transfer-case gear ratio are same for all of the above. It's only the axle ratio that is different.

If that is the case, then the 'crawling ratio' of the CL340 is one of the highest. That's what you mean by "the CL340 goes effortlessly over obstacles" :
3.986 * 2.460 * 4.880 = 47.851 (CL340 Classic)
3.986 * 2.460 * 5.380 = 52.754 (CL340 )


Cheers,

[Samurai]

Thanks Behram, I think I'll leave the axle alone. What do you think about wheel spacers or negative offset rims for improving handling?

Originally Posted by khan_sultan

If that is the case, then the 'crawling ratio' of the CL340 is one of the highest.

Well, my CJ340 can crawl up reasonable inclines with me walking by the side.

[MM440]

Dear Behram.
In a nut shell are you saying that the 43/8 crown pinion set up of the petrol jeeps.i.e. and used in the following vehicles is the best set up for offroading.
1> CJ3B petrol.
2> CL 340
3> Mahindra Armada.
The garage slang to my knowledge for this 43/8 pinion is PETROL CROWN PINION.
If any one wants to upgrade to this configuration all he has to do is tell his mechanic to fit a petrol crown and it will be done.
It will give more torque and pickup and recommended when you also upsize the tires as some of us have done with their machines
Cheers

Originally Posted by DHABHAR.BEHRAM

Dear Sharat - the axle track of CJ340, CL340 and CL340 classic is same (wheel track within 24 mm due to minor difference in wheel rim offsets on model specifications). How can it be majorly different, body envelope is same tyre will foul all over the place if it is changed, even spring seat and shock absorber mountings are different. However CJ340 and CL340 have 5.38:1 (43/8) axle ratio whereas CL340 classic has 4.88:1 (44/9) axle ratio. 5.38:1 is still the best for offroading that's why the CL340 goes effortlessly over obstacles when other vehicles struggle. I hope people will get clarity soon.

In India, there seem to be a dime a dozen establishments just waiting to sell you anything and take your money. Many have burnt their fingers. Please be careful.

Best regards,

Behram Dhabhar

[khan_sultan]

Originally Posted by Samurai

.... Well, my CJ340 can crawl up reasonable inclines with me walking by the side.

No doubt -- the 340's are one of the best jeeps out there and your's is one of them .

Behram, just a small clarification: what are/were the axle ratios for the hurricane engine powered CJ3B's? Same as 340's or different?

[DHABHAR.BEHRAM]

Dear all - now you are all slowly getting enlightened (Gautama Buddha's Bodhi Tree is happening, good) on why the CJ340 / CL340 is the best offroader by far. Yes, it is the driveline optimization characteristics, one of which is axle ratio. Now you know why the Legend performed the way it did when it came to Madikeri a couple of months back. Legend is 3.73:1. There are constraints. There are passby noise / chassis dynamometer BS3 emission regulations to meet, you know. Ha Ha Ha! The hurricane engine powered CJ3B has the 5.38 only. Actually 5.38 is the original ratio of the CJ3B which got carried forward all over the place, including the Armada but not the Armada Grand which was 4.88 (44/9). Your query on interchanging the axle ratio within the same casing is not very easy to answer, there are DANA specifications to refer to as there are various types of centre castings and it all depends which one you have. Therefore I have always been telling you all to refrain from juggads as they will not work, you will only waste money. Therefore, just fitting a bigger tyre may make the vehicle look macho but the immediate effect is that of numerically reducing the final drive ratio, thereby reducing wheelforce on the road (F=a+bv2+mdv/dt) where F is the total wheel force, a is the coefficient of rolling resistance, b is the coefficient of drag, m is the inertia and dv/dt is the acceleration means rate of change of speed with respect to time). Road speed in kms/hr = Engine rpm * 2 * 3.1416 * dynamic rolling radius of the tyre * 60 / gear ratio * axle ratio * 1000. See for yourself, do the calculations. If you want a bigger tyre, you must also have power and torque in the engine upfront to compensate for it otherwise driveability / acceleration will suffer. I have driven a CJ340 (MH01P2540) in 27 Great Escapes in Goa, Rajasthan and all over the place including Madikeri and my vehicle was like a mountain goat, running rings around just about everything. I used to just cut through shrubs, ditches, mud, slush, dry sand et al in order to reach vehicles which were stuck, reverse in front of them, then my technician would latch the chain and I would just yank the vehicle out of its tight spot in no time at all. The technique of driving a CJ340 in a convoy during a great escape (Sharat, this is for you) is to keep it in 4*4 low and then start off in 3rd, shift to 4th and keep going. 4th low is almost same as 2nd high. In case of degree of difficulty increasing, you have 3 fallback gears. The cardinal rule is to go fast / float over obstacles. See the ratios and calculate, you will be amazed at what a CJ340 can do once its wheels leave tarmac. And Sharat, please DO NOT change the wheels on your CJ340. Offset cannot be played around with, you will lose steering geometry big time.

Now for the ultimate kicker - 5.88 ratio was also available, fitting into the CJ340 Dana axle. The number of teeth were 47/8. 47 crown out of 47/11 (4.27) and 8 pinion out of 43/8 (5.38). Only one of the Gleason hypoid generators was especially equipped to machine this pair. It was used in the XDP4.90 engine powered FC360DP straight chassis LCV, first prototypes were made in 1980. The 4WD version, a brown FC climbed all over the place with 1.6 tonnes payload in the platform. I know. How's that? Think about it.

Hope it all comes together now,

Best regards,

Behram Dhabhar

[khan_sultan]

Originally Posted by DHABHAR.BEHRAM

....Yes, it is the driveline optimization characteristics, one of which is axle ratio..... The hurricane engine powered CJ3B has the 5.38 only. ....... If you want a bigger tyre, you must also have power and torque in the engine upfront to compensate for it otherwise driveability / acceleration will suffer. .... my vehicle was like a mountain goat, running rings around just about everything. .......... See the ratios and calculate, you will be amazed at what a CJ340 can do once its wheels leave tarmac. ....

Behram, Your post and information in past few posts are very encouraging -- especially about 'driveline optimization & ratio calculations'. I am all the more happy because I have something coming up for my 'mountain goat -- the MG413W' :-)

Thanks again. your posts give me the confidence that I am on the right track :-)

Cheers,

[Samurai]

Behram, you are a gold mine of information.

Originally Posted by DHABHAR.BEHRAM

See the ratios and calculate, you will be amazed at what a CJ340 can do once its wheels leave tarmac. And Sharat, please DO NOT change the wheels on your CJ340. Offset cannot be played around with, you will lose steering geometry big time.

Actually I was thinking about all this to improve on-road handling. I often have to drive hundreds Kms to reach off-road venues. How did you deal with the on-road handling of your CL340?