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[jarekjeep]

Hi everybody,
Just one long question:
I have shocks 4x, springs 2x, shackles for rear leafsprings 2x, tyres 31 5x. Do ineedanything else to lift my xj? Some people say ineed lower control arms, some say i dont. I know i needto relocate panhard. Anything else?thanks

[jarekjeep]

The second short question is: do i need change the ratio. I'm driving on 31 some time and feel less power butmaybe im wrong. Ireadsomewhere ishould change axles from 2.5 l. I have 4.0ho. It would be shame i justbought front axle which loose with tree. Already on.
Please.give me some advice

[bigjeepzj]

axles of a 2.5 will give you 4.10 ratio
but you will need to swap the your shaft and abs sensors over as 2.5 had no ABS i belive

[isle of man]

4:10 I concur...

[jarekjeep]

Sorry lads i still know nothing. I not to mechanical.

[jarekjeep]

Can anybody explai. Me what is the ratio ?

[The Transporter]

I have 31 x 10.5 s on mine with a 2 inch lift at the front and 2.5 inch lift at the rear.... this is the bare minimum lift for these wheels so 3 inch is better..... The axles are standard and the increase in diameter has made the car a fair bit more leisurely and right on the limit of the axel.... On lock the tyres do rub on the lower control arms but I have temporarily cured this by adjusting the bolts that limit the steering lock

[jarekjeep]

Thanks, now i know more. Still dont understand all this ratio, regearing etc. maybe its better.

[The Transporter]

I don't think that regearing for 31s is too important though our wiser and more experienced posters may wish to correct me

[jay140285]

Jarek,

The tires on my black XJ that you saw are 31's and on standard 4litre axles and as you saw I had no issues with performance so I thnk you will be ok.

I only have a 2inch lift and as you witnessed we did have to take a saw to the bumper but this was more to do with the offset of the wheels I have on.

[Dave69]

the rear axle ratio will not be anything to worry about at this stage. the ratio for the 4.0l is 3.55 and the ratio for the 2.5l is 4.10. this is to take into account the output characteristics of the engine.


you might want to adjust the front track bar to bring the front axle back in the center line of the jeep
when driving the jeep after the installation you might notice a grumbling, this will most likely be the drive line alignment. an easy fix is dropping the gearbox/transfer case by 1" using spacers and also adding 2 degree shims between the rear axle and leaf springs to raise the nose of the diff up.

at 3" lift you will be near the limit of the length of the brake lines, longer lines will be needed for the front and one fro the rear.

[jarekjeep]

Hi, over Easter time I've been visiting one snow country and during play in the forest green lane have stopped on the tree. Upss
Life... Anyway I have 4.0 petrol with 3"lift and 31 tyres. I replaced the front axle for the same. Was it mistake? I feel sometimes my xj has not enough power. Maybe I'm wrong but maybe not. Does axle with rating 4.11 from 2.5petrol make my vehicle drive faster, or rather accelerate better? What about mpg? I don't really care now- just want to know. Without regearing on 31tyres with 3"lift and trimmed under the front bumper full tank lets drive just 175miles, and I know it lie a bit(10per cent I suppose???)
Do change the axle for one from 2.5 or not?

[The Transporter]

With the axle ratio that you suggest, your car will be lower geared and so will accelerate quicker.... If you feel that the engine is lacking in power with your 31 inch tyres then a lower ratio axle may be the way to go but I don't feel that mine needs it..