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Old 14th July 2009, 13:48   #1
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Default Raising a Jeep's ground clearance : Options?

Top on the wishlist of any offroader is additional ground clearance, you can never have enough, right? My Jeep has taken a couple of hard knocks over the last 3 months of offroading. What are the different options available to improve ground clearance, and which of those are most recommended?

1. Taller tyres : The simplest & cheapest. You can go as long as your stock setup will allow, such that the tyres don't rub against the body / components.

2. Alter leaf springs / suspension + larger tyres. Simpler than SPoA, but limited potential (only bend the leaf springs). Also, the ones I've driven have had a very stiff ride (not that stock ride quality was comfortable to begin with!!).

3. SPoA : A modification that's only getting more popular with Team-BHP's offroaders. Massive tyres permissible. Downsides?

4. Suspension Lift kits : Most complicated. New coils, shocks etc. etc. need to be sourced. Not the simplest job to calculate bump stops wheel travel etc. Better for IFS than our setups (?). While new Jeep Wranglers may benefit from ready after-market support, it's not necessarily the case for our Mahindras.

5. Body lift kits : Never been too keen on this. They only lift the body up (and not the suspension). I call this "artificial ground clearance", if done alone, though it may have some value if the body lift is complimenting a suspension lift job.

Are there any other ways that I've missed out on? How much (max) should a Mahindra / Gypsy's ground clearance be increased by?

Last edited by GTO : 14th July 2009 at 13:55.
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Old 14th July 2009, 13:54   #2
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Other then taller tyres + bigger rims. I dont think there is any other way to increase the GC for a Mahindra.

Will wait for the pro's to come out with suggestions.

Last edited by Spitfire : 14th July 2009 at 13:59.
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Old 14th July 2009, 13:59   #3
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Quote:
Originally Posted by Spitfire View Post
Other then taller tyres + bigger rims. Nothing else increases the GC.
I'm no expert in this, but I tend to agree with this, becuase a taller suspension or lifted up body is not actually going to increase the height of the wheel center and the height of your axle housing - which decides your ground clearence.

Last edited by clevermax : 14th July 2009 at 14:02.
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Old 14th July 2009, 14:06   #4
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Quote:
Originally Posted by Spitfire View Post
Other then taller tyres + bigger rims. I dont think there is any other way to increase the GC for a Mahindra.
Quote:
Originally Posted by clevermax View Post
becuase a taller suspension or lifted up body is not actually going to increase the height of the wheel center and the height of your axle housing - which decides your ground clearence.
Which of the above-mentioned mods are most recommended - to maximise the tyre size - and why? My Jeep in its current form can't take more than a +1 upsize.
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Old 14th July 2009, 14:24   #5
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Default True Ground Clearance

Hi GTO,

You have raised some very interesting questions.

True GC is the distance between the ground and the lowest part of the vehicle, most often the Differential.

Then the Cheapest Solution is to go for taller tyres.

If the belly/cross member Clearance is considered then, again
1) taller tyres help mildly

2) Suspension Lift helps some more

3) SPOA helps the maximum, but is the most complicated to execute.

If you need more space under the Differential then Taller Tyres 31-10.5-15 is max what the CJ3B can take, to make it more maneuverable you will have to go for MM540 front differential (51" vs 48.5").

The its advisable to Lower you diff-ratio to 4.88:1 or 5.38:1, to compensate for the heavier tyre.


1. Taller tyres : The simplest & cheapest. You can go as long as your stock setup will allow, such that the tyres don't rub against the body / components.

Tried and tested, mechanical mods are bolt on.

2. Alter leaf springs / suspension + larger tyres. Simpler than SPoA, but limited potential (only bend the leaf springs). Also, the ones I've driven have had a very stiff ride (not that stock ride quality was comfortable to begin with!!).

Available in USA costs between 14-60K Leaf spring lift kits. again tried and tested and bolt on.

3. SPoA : A modification that's only getting more popular with Team-BHP's offroaders. Massive tyres permissible. Downsides?

Downsides
1) Steering Angle
2) Differential Pinion Angle & Traction Bars
3) Setup of the Steering Linkages
4) Induced body roll.
5) The leaf spring wears out faster in a SPOA setup.

Ask yourself the WHY of SPOA?
Why do you want to get more room above the tyre is it articulation or to put taller tyres, and get better under the differential clearance, and belly clearance?

4. Suspension Lift kits : Most complicated. New coils, shocks etc. etc. need to be sourced. Not the simplest job to calculate bump stops wheel travel etc. Better for IFS than our setups (?). While new Jeep Wranglers may benefit from ready after-market support, it's not necessarily the case for our Mahindras.

Available for CJ5/CJ7 i.e M&M CJ3B and MM540.

5. Body lift kits : Never been too keen on this. They only lift the body up (and not the suspension). I call this "artificial ground clearance", if done alone, though it may have some value if the body lift is complimenting a suspension lift job.

Not at all recomended, maybe you can go in for the MM540 style body beds, over the CJ series, rubberised-canvas beds, thereby you will get 1/2 to 1 inch height.

My suggestion.
Stage - 1
1) Change Front Axle/Diff-Housing to MM540 i.e 51" track & 4.88:1 diff-ratio
2) Rear Axle to full-Floating with Auto Lockers/LSD i.e 48.5" track 4.88:1 diff-ratio
3) Upgrade tyres to Maxxis Mudzilla 31-10.50-15
4) MM550XD style Skid-Plate under transmission Cross Member.

Stage - 2
1) Upgrade steering system to 1996 Armada type, it bolt on for CJ & MM540s
2) Shock Absorbers - Bilstein 5100 series
3) Steering Damper
4) Front LSD

Stage - 3
NGCS MM550XD and start all over again.

Regards,

Arka
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Old 14th July 2009, 14:36   #6
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Quote:
Originally Posted by GTO View Post
to maximise the tyre size
Talking from a CJ\CL 340 perspective, the way to go was - SPOA + Spacers, dependng upon the upsize, the lift and spacer dimensions had to be calculated.

Another thing when it came to tyres is, the more you upsize with better offroading tread the weight of the tyres increases.

But the costs were too high and the engineering finesse of the Garage was suspect.

Maybe a project for another day.
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Old 14th July 2009, 14:47   #7
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You can raise a Jeep by 2 inches by various methods.

Use bigger tyres / rims - You are making the gear ratios taller, not very good for off road where a 4:1 first gear ratio is desired and particularly the 2nd gear ratio gets taller which is a bad thing.

Lift the suspension - In an Indian Jeep a 1 inch lift can be managed by altering the tension and U bolt in the leaf springs - But again for an off road vehicle raising the CG makes it that much prone to rolling offroad, a sand roll is manageable but a roll on hard mud incline is best avoided.

My opinion is let it be as it is, we dont exactly need a rock crawler here. If we do then a roll cage, tyres, gearbox change and everything else to make a Jeep rock crawler needs to be considered, not half measures.
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Old 14th July 2009, 15:07   #8
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Quote:
Originally Posted by GTO View Post
..
1. Taller tyres : The simplest & cheapest. You can go as long as your stock setup will allow, such that the tyres don't rub against the body / components.
As you said that it is the easiest way to increase the height. Here are some things to be aware of :
  • This can reduce your articulation if the clearance between the wheels & wheel wells is not adequate for tyres to move up. I think in a MM, this should be less of an issue in the front but may be an issue in the rear (not sure but do check)
  • It will impact your final drive ratio. Taller tyres will reduce your crawling speed (assuming rest things are same as before).
  • From a pure off-roading perspective I don't think one would be too worried about speedo error etc etc
Quote:
2. Alter leaf springs / suspension + larger tyres. Simpler than SPoA, but limited potential (only bend the leaf springs). Also, the ones I've driven have had a very stiff ride (not that stock ride quality was comfortable to begin with!!).
Apart from that, I have heard that recambering also makes the leafs more brittle and they become prone to breakage. But this is a very common way to go to achieve clearance using after market springs from EMU etc etc..

Quote:
3. SPoA : A modification that's only getting more popular with Team-BHP's offroaders. Massive tyres permissible. Downsides?
This allows you to start from where the previous 2 ways would reach their end. Downsides or points to be aware of:
  • Need traction bar to prevent axle wrap (especially in high torque vehicles)
  • Longer brake lines, either new DS or DS spacers, Steering (Most important)
  • With a SWB vehicle, the body roll would increase
With same tyres, your diff height would remain same as before with SPoA BUT the quality of the GC would increase manifold. This is because the leafs are now out of the way and you can take angles that you couldn't take before and your leafs would hit.

Can easily give you a minimum of 4-5" of lift.

Quote:
4. Suspension Lift kits : Most complicated. New coils, shocks etc. etc. need to be sourced. Not the simplest job to calculate bump stops wheel travel etc. Better for IFS than our setups (?). While new Jeep Wranglers may benefit from ready after-market support, it's not necessarily the case for our Mahindras.
Shacke reversal, longer shackels, RUF (rear springs up front) are also some ways for leaf spring vehicles and at times these are also passed of as suspension lift kits.

Coil conversion is complex (from calculating exact measurements) and fabrication needs to be 100% precise else it will ruin the vehicle forever literaly. Then welding etc etc are also complex things here as a weld just off by few mm could make a difference.

Also, all calculations are done with a tyre size in mind. So if you later change to a tyre with different spec then your coil job could be off from a measurement perspective.

Quote:
5. Body lift kits : Never been too keen on this. They only lift the body up (and not the suspension). I call this "artificial ground clearance", if done alone, though it may have some value if the body lift is complimenting a suspension lift job.
Virtual lift. One can easily get upto 1" of lift -- easy and simple but not used much by folks

Quote:
Are there any other ways that I've missed out on? How much (max) should a Mahindra / Gypsy's ground clearance be increased by?
For a Gypsy I have read somewhere that upto 8" of increase is OK and not an issue. That would be good enough to run 34-35" tyres. But that would then call for host of other mods also.

Last edited by khan_sultan : 14th July 2009 at 15:09.
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Old 14th July 2009, 15:30   #9
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My 2cents here (I am a newbie to jeeps, so please feel free to ROFL if its stupid)

1) Hummer Technology:

I remember reading some where that Hummer's GC is acheived by the drive shaft not driving the center of the HUB like ALL other vehicle's on the road. It instead drives a 'sort of' 2nd transfer case which is conected to the wheels... See Hummer front axle pic and 'CAD' pic below.

2) Now - if someone can break their skull out and design something similar on a Jeep Chassis (I made a DUMB Picture using Ganesh's gbanavar chassis) it MAY increase the GC.
Attached Thumbnails
Raising a Jeep's ground clearance : Options?-fheads-chassis.jpg  

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Old 14th July 2009, 15:54   #10
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Quote:
Originally Posted by svsantosh View Post
My 2cents here (I am a newbie to jeeps, so please feel free to ROFL if its stupid)

1) Hummer Technology:

I remember reading some where that Hummer's GC is acheived by the drive shaft not driving the center of the HUB like ALL other vehicle's on the road. It instead drives a 'sort of' 2nd transfer case which is conected to the wheels... See Hummer front axle pic and 'CAD' pic below.

2) Now - if someone can break their skull out and design something similar on a Jeep Chassis (I made a DUMB Picture using Ganesh's gbanavar chassis) it MAY increase the GC.
this can be achieved only with an all 4 wheel independent suspension ( the other way round also works)

tryin to retro fit this kind of set up on our older generation jeeps/ gypsies would be very tough.

Last edited by siddartha : 14th July 2009 at 15:56.
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Old 14th July 2009, 16:05   #11
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I don't think I can add much, everything I can think of and more has been covered by the Gurus.

But one has to keep in mind that SWB has less tolerance towards any kind of lifts, it can increase the body roll easily.

Quote:
Originally Posted by ex670c View Post
My suggestion.
Stage - 1
1) Change Front Axle/Diff-Housing to MM540 i.e 51" track & 4.88:1 diff-ratio
Arka, didn't the Classic come with 4.88:1 ratio and 51 inch track? GTO has a Classic.
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Old 14th July 2009, 16:06   #12
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Quote:
Originally Posted by svsantosh View Post
design something similar on a Jeep Chassis
Thats called Independent suspension.

This is not an option. It would require serious engineering to convert a solid axle vehicle to a Independent suspension one.

And then there is a raging debate as to whether Independent suspension or solid axle is the better way to go offroading.

There is a thread somewhere on that too.

Quote:
Originally Posted by Samurai View Post
the Classic come with 4.88:1 ratio and 51 inch track?
Correct about the axle ratio. Crown/Pinion:44/9 - 4.88:1

But the track is 48" - 1230mm, 51" - 1290mm is MM540.

Last edited by Spitfire : 14th July 2009 at 16:19.
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Old 14th July 2009, 17:07   #13
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Thanks for the detailed comments, fellow offroaders!

Quote:
Originally Posted by ex670c View Post
SPOA helps the maximum, but is the most complicated to execute.
Quote:
Downsides
1) Steering Angle
2) Differential Pinion Angle & Traction Bars
3) Setup of the Steering Linkages
4) Induced body roll.
5) The leaf spring wears out faster in a SPOA setup.
Considering how much I value reliability, and that my work schedule does not permit me to visit garages frequently, this is the only put off. I've been toying with the idea of an SPoA since May, but the complications have me sitting on the fence.

Quote:
to make it more maneuverable you will have to go for MM540 front differential (51" vs 48.5").
Noted.

Quote:
The its advisable to Lower you diff-ratio to 4.88:1 or 5.38:1, to compensate for the heavier tyre.
Truely. I've actually used 1st low at times and can't afford a taller ratio. Will go low on the diff.

Quote:
Why do you want to get more room above the tyre is it articulation or to put taller tyres, and get better under the differential clearance, and belly clearance?
My immediate requirement is ground clearance. Classic's never left me wanting on the articulation front.

Quote:
1) Change Front Axle/Diff-Housing to MM540 i.e 51" track & 4.88:1 diff-ratio
2) Rear Axle to full-Floating with Auto Lockers/LSD i.e 48.5" track 4.88:1 diff-ratio
3) Upgrade tyres to Maxxis Mudzilla 31-10.50-15
4) MM550XD style Skid-Plate under transmission Cross Member.
Most probably, that's what I'm going to start with. Can my Classic take the 31-10.50-15 in stock form? If so, how much additional clearance will I get?

Betweek the leaf spring kits, and the suspension lift kits, that you say are bolt on, which one would you recommend? What's the additional ground clearance, and maximum tyre size that I can go for with them?

Quote:
1) Upgrade steering system to 1996 Armada type, it bolt on for CJ & MM540s
2) Shock Absorbers - Bilstein 5100 series
3) Steering Damper
What is the advantage of each of these 3 points?

Quote:
Originally Posted by Spitfire View Post
Another thing when it came to tyres is, the more you upsize with better offroading tread the weight of the tyres increases.
Something on my mind for sure. I've seen how larger tyres sap the engine of performance, and my CJ, even with the 2.5, isn't exactly a scorcher. One of the reasons I don't want to go in for an overtly large / fat tyre.

Quote:
Originally Posted by desertfox View Post
My opinion is let it be as it is
I'm going to severely damage my Jeep unless I get more ground clearance.

Quote:
Originally Posted by khan_sultan View Post
Apart from that, I have heard that recambering also makes the leafs more brittle and they become prone to breakage.
Would those CF leaf springs help in anyway here?

Quote:
Coil conversion is complex (from calculating exact measurements) and fabrication needs to be 100% precise
Not keen on coil conversions.

Quote:
That would be good enough to run 34-35" tyres
You have the horsepower, we don't!

Quote:
Originally Posted by Samurai View Post
But one has to keep in mind that SWB has less tolerance towards any kind of lifts, it can increase the body roll easily.
True. After reading up on everyone's responses, I'm thinking of a modest lift (rather than the original SPoA plan).

Sitll going to think it through though.
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Old 15th July 2009, 09:21   #14
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Quote:
Originally Posted by ex670c View Post
to make it more maneuverable you will have to go for MM540 front differential (51" vs 48.5").
Quote:
Change Front Axle/Diff-Housing to MM540 i.e 51" track & 4.88:1 diff-ratio
Arka, another thought : Should only the front be changed to 540 spec or the rear as well (for equality)?
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Old 15th July 2009, 10:11   #15
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Default Part2 - The Explanations

Hi GTO,

I believe your JEEP is running 4.27:1 as you had changed it earlier.

1) MM540 Front Axle/Housing & M&M Classic Knuckles & Disc Brakes - Improves the front track and the vehicle follows with in that track i.e less steering wander.

2) The MM540 Rear Axle/Housing can be fitted - but not worth the trouble.

3) If you are pushing 31-10.50-15 then you will need a beefier steering box.

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

5)Bilstein Shocks - Better rebound.

6) Leaf Spring Kit vs Suspension Lift Kit - essentially the same, suspension lift kits come with Shock absorbers, leaf spring Bushes and little tid-bits.

7) The max size on a CJ3B/CJ5 stock is 7.50X16 i.e 31", with out trimming the rear fenders/wheel arches.

8) For a 31" tyre you will get 31-28 = 3" by 2 = 1.5" at least, so from 8" you get 9.5" = 241mm . That is Gurkha Territory

Regards,

Arka

PS - Check your XD3P if it is a XD3PU then get a MM550XD FIP rated 76bhp at 4600rpm & 15.5kgm

Last edited by ex670c : 15th July 2009 at 10:20.
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