[Sudarshan]

Originally Posted by AVR

Another simple advantage that drove my choice of dogbone shackles was that when you upsize tires, the longer shackles compensate for the reduced gap between tyre and fender.

you have sorted it out temporarily ( IMHO ) , the fender needs to be re fabricated ( Again IMHO )

@Sudarshan bhai,

Also, how did longer shackles result in a disadvantage articulation-wise?

AFAIK & IMHO Articulation means travel of wheels in both directions UP & DOWN
So answer to your Question will be

Clue 1 if you preload the springs more what will happen ? that happens exactly with the longer shackles wheels just don't go up enough ( they may go down enough - but that too looks doubtful here )

Clue 2 Apart from the theoretical view in the above ; I have watched the two vehicles ( Mentioned above in my post as Kunal's & Kishorda's ) doing same obstacle differently , the longer shackled actually see sawed at some point the roll was much more than the other vehicle

Clue 3 we need actual ramp study for this comparing the two vehicles ,

need to think more on this ,still have few doubts ( like you ) as to what happens 'Exactly ' with longer shackles , thats why I have put the query here

Sudarshan

[Sudarshan]

Ok let me rephrase my question ,

why is shackle on particular vehicle ( cj 3 or 540 ) is of a particular length , -- say 4.25 " . Why its not 5" or 4" ? whats the RULE that decides the shackle length .

suppose I am using 48" long ( main leaf ) spring assy , what is the shackle length ? what factors (terrain , spring curve ,flex etc ? ) determine the shackle length

OR other way round --, suppose I want to lift my vehicle --MM 540 --for 2" ( by long shackle method ) what length of shackle & springs ( also --yes ) I should be using ? keeping in mind that I am ready to modify/ adjust the prop shaft length or its slider .

Whats the key to this shackle length thing ?

Sudarshan

[headers]

^^^:

Apart from above, dont you think the Shock absorber travel plays a role?

I think the shock absorbers, the leaf spring pack and the wheel travel [vertical] of the vehicle is restricted by design to a certain maximum limit and this differs for a CJxx and a MMxx.

IIRC, the NGCS has a different perch point [courtesy Vinod_Nookala] which gives it a better suspension than a MM540 I guess

Maybe Spike can help with the formulaes? Diagrams?

[AVR]

Originally Posted by Sudarshan

Clue 1 if you preload the springs more what will happen ? that happens exactly with the longer shackles wheels just don't go up enough ( they may go down enough - but that too looks doubtful here )

Isn't this compensated by longer travel shocks (I used Savari shocks when I fitted the shackles). Longer travel shocks would also essentially be longer and have a preload closer to what longer shackles would require as compared to stock.

I think that's what Headers is also referring to below.

Originally Posted by headers

Apart from above, dont you think the Shock absorber travel plays a role?

Originally Posted by Sudarshan

why is shackle on particular vehicle ( cj 3 or 540 ) is of a particular length , -- say 4.25 " . Why its not 5" or 4" ? whats the RULE that decides the shackle length .
what factors (terrain , spring curve ,flex etc ? ) determine the shackle length
Whats the key to this shackle length thing ?

Interesting question. While I had love to know the exact method of determining shackle length, something enlightening that comes to mind in the words of the brilliant Bill Watterson



Source: Internet search
@Mods - Not sure if I can paste an image just using "Internet search" as a source. Please delete if inappropriate.

[Sudarshan]

Originally Posted by headers

^^^:

Apart from above, dont you think the Shock absorber travel plays a role?

No I dont think so , Once you adjust/change the shockabs for the required travel limits ( maximum stretch & compress ) the consideration is over , wrt axle up & down travel .

Sohockabs are essentially dampers they will just control the rate of 'swinging ' & that too to reduce rapid ' jerks ' . I dont think dampers are relevant in 1st Low crawl . ( unless used as preloaded or coupled with springs ( coil springs around it ), Ahh you are talking about such ?

IIRC, the NGCS has a different perch point [courtesy Vinod_Nookala] which gives it a better suspension than a MM540 I guess

maybe , but thats the standard design , dont know much on that

Originally Posted by AVR

Isn't this compensated by longer travel shocks (I used Savari shocks when I fitted the shackles). Longer travel shocks would also essentially be longer and have a preload closer to what longer shackles would require as compared to stock.

what you have done is adjusting the longer down travel ( & may be compression ) of shockabs with the extended shackles , otherwise the standard ones would not have worked properly

the words of the brilliant Bill Watterson

Brilliant -- this is how WE do things , till they break & then find the way to correct it

Sudarshan

[headers]

Originally Posted by Sudarshan

why is shackle on particular vehicle ( cj 3 or 540 ) is of a particular length , -- say 4.25 " . Why its not 5" or 4" ? whats the RULE that decides the shackle length .
...
Whats the key to this shackle length thing ?

Sudarshan

The rule is defined by design sir!! The drivetrain components that go into building the vehicle as well as the max articulation it can achieve safely!!

Originally Posted by Sudarshan

Sohockabs are essentially dampers they will just control the rate of 'swinging ' & that too to reduce rapid ' jerks ' . I dont think dampers are relevant in 1st Low crawl . ( unless used as preloaded or coupled with springs ( coil springs around it ), Ahh you are talking about such ?



maybe , but thats the standard design , dont know much on that

Now, why did they change the perch points for the NGCS? Obviously to better the older 540s suspension setup.

Now, these AFAIK are extensively tested in CAD/CAM before production to check for feasibility and weakness areas. A FMEA would definitely have been done. We [normal guys] cannot get access to such documents are they are classified documents pertaining to processes.

What we will be doing is our own thoughts as to why a certain design was done etc without understanding the underlying reason.

Ofcourse, we will add to the page and post counts

[VANOS]

hi guys,
as far as all i have learnt from this thread, i still cant come to a conclusion as far as my mm540 is concerned. so i can conclude that except for the stock setup anything else is a trial and error setup, a hit or miss. Or is there an error free set up? if so please keep me informed. i'll take your word for it.

[fazalaliadil]

Originally Posted by VANOS

hi guys,
as far as all i have learnt from this thread, i still cant come to a conclusion as far as my mm540 is concerned. so i can conclude that except for the stock setup anything else is a trial and error setup, a hit or miss. Or is there an error free set up? if so please keep me informed. i'll take your word for it.

VANOS,

Bottom line is..there is no way you can increase the GC of a stock vehicle except to go for bigger tyres.

By Ground Clearance what we are talking here exactly is the bottom most point of, differential pumpkin bottom point, leaf spring etc. As far as my experience goes, this is the only way GC can be increased/ achieved.

Longer shackles, lift, SPoA etc. will not increase the above mentioned GC, though it will help in articulation and avoid wheel lock in the tyre wells.

Bigger tyres is neither a hit and miss or trial and error, it is a sure shot way of gaining on GC.
Regards,

[DirtyDan]

Originally Posted by VANOS

... so i can conclude that except for the stock setup anything else is a trial and error setup, a hit or miss....

What do you consider to be a "success"? Larger tyres (taller tyres) will raise the G.C. to the axles but you can also raise the chassis. There are trade offs to be considered either way. Raising means loss of stability and maybe some decrease in handling and agility.. best to ask someone who has had some "success" with what they did. Better yet, drive his vehicle and see if you like it.

[VANOS]

Originally Posted by fazalaliadil

VANOS,

Bottom line is..there is no way you can increase the GC of a stock vehicle except to go for bigger tyres.

By Ground Clearance what we are talking here exactly is the bottom most point of, differential pumpkin bottom point, leaf spring etc. As far as my experience goes, this is the only way GC can be increased/ achieved.

Longer shackles, lift, SPoA etc. will not increase the above mentioned GC, though it will help in articulation and avoid wheel lock in the tyre wells.

Bigger tyres is neither a hit and miss or trial and error, it is a sure shot way of gaining on GC.
Regards,

Originally Posted by DirtyDan

What do you consider to be a "success"? Larger tyres (taller tyres) will raise the G.C. to the axles but you can also raise the chassis. There are trade offs to be considered either way. Raising means loss of stability and maybe some decrease in handling and agility.. best to ask someone who has had some "success" with what they did. Better yet, drive his vehicle and see if you like it.

Thanks a lot Fazal and Dan,
Larger wheels is a sure shot deal. I got that thanks. There is word aflote that carbon fiber springs are available. Is it true, if so what would it cost. Advantage and disadvantages. On a different topic i was thinking if i lift my car bout 6inches considering transfer case the lowest point, then fit 2 or 3 inch spaces to the springs before fitting the diff and U clamp, that may give me a lift at the diff. Please let me know what you think. I'll send you a rough sketch if you need one
Regards.

[vivekgm]

Originally Posted by vak

1. Fitment of 31-10.5-15 Yokohama Geolander AT-s
2. Recambering of the leaf springs
3. Fitment of longer shackles plates

The ground clearances before and after the mods are given below.

Hi Vinshad,
Could you please let me know where you got your modifications done. I would like to do the same to my Bolero DI 4x4. I'm from Palakkad.

[Roja]

hey,

right so i have a 410w, stock, only mods are maxxis treps tires.

i use the vehicle for work, which invloves what city dweller will term as OFFROADING , and i do use it for proper offroading a few times a month.
to be honest i have gone through many threads and photos of folks really lifting their gypsies, and am sure there are advantages, but i would like to say that mine in stock form can pretty much pull through everything. also since I am located in a place where expertise and parts are far and between.

the only thing that i would like to do to get a very slight lift, is temper the leaf springs.

i am not techincal or anything, so if someone can help me and tell me is this okay to do?
any issues forseen? or any alternate way other than spoa ?
thanks a bunch

attached are a few photos - from what she looked like before - to what she is now

r

[Roja]

Hello,
I was just wondering if I can get an answer to my question please? Would really help since I thought members here would be able to help me?

Thank you in advance
R

[wooka]

Originally Posted by ex670c

Hi GTO,

4) The Steering Damper reduces Kingpin wear which lead to "THE DEATH WOBBLE"

Sorry to revive an old thread- but can the steering damper be fitted to a 2015 CRDe refresh? The steering feedback on every undulation makes my wrists give up on very long drives.