Lift kit


#1

I have a 96 Jeep Cherokee Sport and do some mild to moderate off-roading. I was thinking about getting a lift kit. However, since the axles are the lowest part of this vehicle, and a lift kit would have no effect on the axles, I was wondering, what would be the advantage of a lift kit? I wouldn’t have any more ground clearance. I guess with the kit I could put on larger tires which might give a slight increase in ground clearance, but is there any other advantage?


#2

Suspension lift gives you two benefits: room for larger tires (greater ground clearance) and more importantly, more suspension travel for better wheel articulation. The farther you can get a wheel to droop when the opposite side is compressed up in to the rig because of the terrain, the better traction you will have.

Most of the time in off-roading, you don’t really want the rig to be all that high off of the ground. You want the bottom to be as far from obstacles as possible, but you want the roof to be as close to the ground as possible to make it more maneuverable and less prone to roll-over. Do as much suspension lift as you need to clear tires or what-have-you, but not so much that you’re scraping the roof under overpasses.

Edit: Here’s a decent page on lift and RTI.

http://www.erau4x4.com/TheRamp.html


#3

Thanks mr josh-I had never thought of the wheel articulation.


#4

That jeep has a big solid front axle-- you’re right that the ground clearance will only improve as much as the increase in tire size. A lot of the old timers out here in Montana used to keep a winter truck with 4wd and a summer 2wd truck because the 4wd’s have a solid front axle, whereas the 2wd’s had independant front suspensions and better ground clearance. Of course, today you have the best of both worlds with IFS 4 wheel drive trucks that have CV joints like a front-drive car.

You can probably lift your jeep a couple inches to sandwich in some bigger tires without installing a full-blown lift kit. A jeep-specific forum can probably tell you details.


#5

Well, you are partly right about the axles, but remember that at every point other than at the wheel they will be higher and all the other parts of the car will be higher. So for the most part you will have additional ground clearance. It is even better than that because if the high point is need a wheel and close to that low point the axel, it also means that the wheel is likely also going to hit it and raise the car up out of the way at that point.


#6

The solid front axle in his Jeep is better for most off-road applications than IFS. IFS has terrible articulation and less strength compared to solid axle arrangements. As for ground clearance; the IFS clearance is non constant under the diff. whereas the solid axle is constant. As the suspension compresses on an IFS truck the ground clearance decreases under the diff. IFS rides nicer primarily due to less unsprung weight and is better for high speed off road activities such as the BAJA or many military applications. For most of us though the solid axle is the superior off-road setup due to reliability, strength, articulation and the ability to accept a front locker (most IFS setups are not strong enough to run a front locker).


#7

Another thing to consider is that when you increase your tire size your effective gear ratio gets higher (numerically lower) If you run anything larger than a 31 or 32in tire on your jeep you will probably want to re-gear the differentials to correct for the tire size change. As an example; I went from 3.42:1 gears to 4.10:1 when I swithed from 31" to 33" tires, which gave me a great all-around ratio for both highway and offroad.

Here is one site that you can check out for more info:
http://www.jeepforum.com/forum/index.php


#8

Lifting the body and putting lager tires on would hav ethe advantages that others have stated, however it’s important to be aware of some tradeoffs. Lifted bodies increase the universal joint angles and most of the srticulated angles in the suspension, increasing wear on the joints. Larger tires are heavier and, assuming you get something more aggressive, will have more rolling resistance. These things combined do create more load and thus more wear on the drivtrain. And, of course, your gas mileage will take a hit.


#9

But the biggest “benefit” of all is you raise the already high center of gravity making a roll-over accident even more likely than it already is. If you are like most SUV drivers and operate your vehicle on dry pavement 98% of the time, leave the suspension alone.


#10

Well here’s the thing: the XJs have Dana 35 rears and I think a Dana 30 front axle. I wouldn’t run anything over 33" tires on anything less than a Dana 44 because they’re pretty weak. Small ring gears, small axle shafts, weak ball joints. 31" tires would be perfect for an XJ, and I think you can do 33s without trimming the fenders, but if you only do mild offroading, there’s no need to go that route.

A 2" suspension lift will not change your u-joint angles enough to cause a radical change in wear. If you go much more than that in a short-wheelbase rig, then you absolutely do need to clock down the transfer case to flatten out the u-joint angles.

A set of 31 x 10.50 tires are not that much larger than the stock tires on an XJ and should fit without a lift. BF Goodrich makes a good all-terrain tire in that size. As for larger tires causing extra wear, that’s somewhat true, more specifically in the front and primarily on ball joints on these smaller Dana axles. Like I said, 31s aren’t that much larger than stock, and won’t cause any noticeable extra wear. Bump up to some heavier 33x10.5 or 33x12.5 and you will start to see ball joint wear come more quickly.

All just thoughts, plenty debatable.