Not that it matters to me, I drive a 2wd X But:

Why would someone want a solid front axle as opposed to the front axle system currently on the X?

And wouldnt a solid front axle make for a rougher ride on pavement?

This discussion came up at work the other day and I had no idea how to respond.

Can some of you 4wd gurus help me out here?
Oh and keep it simple.

Averysx,
My take would be that a solid axle is more robust than the IFS setup that the Xterra has. For example, my Rovers have a solid axle on leaf springs. The only suspension adjustment is toe-in, which can be done in minutes. Everything else just bolts together.

The other thing is that you don't have to deal with CV joints. I just have axles and drive flanges since there's no flexing in the axle shaft. Thats' just more stuff that won't wear out. I should add, that instead of a CV joint in the front axle shafts, there are ujoints, to take into account the steering action.

That all being said, most people would consider that the Rover has a bit of a buckboard ride.

Bogatyr

You are a wise man Sensai.

Here's what Ive learned from both of your replies:

1. A solid front axle provides more suspension travel keeping both tires on the ground more of the time.

2. A solid front axle provides more ground clearance.
Is that the main reasons for a solid front axle?

That being asked, how come more car companies don't offer a solid front axle on there vehicles that are marketed as "off-road" vehicles or in Nissans case "Go-anywhere" vehicles?
Let me add that I am by no means an off-road vehicle expert and there may be companies offering this that I don't know about.

Another advantage is fewer parts to break.

The common though is that most vehicles that are marketed as rugged are rarely used for that actual purpose. A straight axle generally provides a harsher on road ride in that even though you have great articulation, one wheel is allways reacting to what the other wheel is doing. With an IFS vehicle one tire can be slamming through a pothole and it will not affect the other tire.

You can get lots of suspension travel from IFS, you just have to spend lots of money, craft extremely strong parts, and have a very wide track for the length of the arms. For off-road racing IFS is preferred. The Ford I-beam suspension (TTB) is also cabable of great suspenion travel.

But with strength and articulation being paramount to rock crawling type off roading the straight axle is preferred for it's strength and simplicity.

ok maybe i am wrong here but a solid front axle will decrease your front ground clearance due to the pumpkin.... for example whenver you hang up i bet its on the back diff on your X.....

Hence the H1 with no solid axles.... = 22in of ground clearance or something like that

Ground clearance isn't the whole point.

You're right; the solid axle will actually decrease ground clearnace between the wheels. However, the extra flexability will balance that out and the solid axle makes it easier to increase ground clearance for the body. BTW, the Hummer has a very special independent suspension and it was never intended for rock crawling or normal offroading (and it sucks at both). It was built to haul people across the desert and it does that well.

Mainly because most vehicle (ours included) may be marketed as "go anywhere" vehicles, but are NOT marketed as offroading vehicles. That is, they advertise them to be able to go "off the beaten path," but not rock-crawling, mud-bogging, etc. vehicles.

The independent suspension gives a smoother ride than a solid axle, and that's what Joe Public wants. Hence Jeep and Land Rover buckling under that demand and putting IFS and/or IRS in their Liberties, Freelanders, Range Rovers and soon to the Grand Cherokees and Discoveries.

Don't be shocked when about 4-5 years down the line, even the Wrangler has it.

I would crap my pants if they did that to the Wrangler.

Better get your Depends. It will happen.

On the TJ ? Not a chance.
Jeep can continue to introduce new vehicles like the Liberty with IFS if they choose.

and there will be an outcry from the jeep-offroad community the likes of which you have never heard.

Jeep can and will continue to introduce new SUV's w/ IFS - and that will include the Wrangler at some point. The bottom line is a more comfortable and civilized Wrangler will sell more, and that is what Jeep cares about - not satisfying the small percentage of people who actually lift and wheel their Jeeps.

I disagree. I see more lifted TJ's in Colorado than stock TJ's. Jeep spends billions of dollars every year marketing Jeeps as off-road vehicles, not civilized, comfortable cars.

The TJ is the most impractical vehicle ever made, there is no reason to make it practical when the Liberty or a similar SUV will suffice.

I've driven a Grand Cherokee, and prefer the solid axle ride to my IFS Xterra, it's much more civilized and comfortable.

I think Jeep makes all that money by selling the image of capable an uncivilized SUV's. Look at the Liberty - it's been neck-in-neck w/ the Escape for the top selling small SUV in the country every year since it was introduced. It's the image that sells to most people, not the actual capability.

Side note - You really think the WJ has a better ride than the Xterra? My Dad used to have one and I always found it to feel kinda floaty and disconnected. Just personal preferences, I suppose.

DC tends to disagree...

About the Icon (wishbone suspension front and rear):

"Jeep Icon is a creative exploration for a next-generation Jeep Wrangler," said John E. Herlitz, Chrysler Corporation's Vice President of Product Design. "It's solid, stable, built like a rock, and its capabilities have been further enhanced."

(though, in fairness, the next generation Wrangler is rumored to be called the VJ, not the TJ)

I didn't find the Grand CHerokee to have such a great ride? I too find them to be disconnected at speed and when the pavement is lumpy they jiggle around a lot. What I hate the most about them is the side to side stiffness when they start rocking. The Liberty suffers from this too. It's like there's a certain amount of loose roll and then when they get to a certain point it's jarring. IMO, the Xterra is the best handling and riding SUV on the road; at least of all those I have driven or ridden in. Even kicks ass against my Brother's Expedition.

Its not why would you want a solid front axle. Its why wouldnt you want a solid front axle. as my sig says, IFS sucks.

All I can add to this is that prior to the X I owned a 94 Ford Exploder. It had the I-beam style front suspension and it sucked, And I do mean it was the worst goddamn ride of any vehicle Ive ever driven. It also ate tires like nothing and it was impossible to align. If the solid front axle acts anything even remotely like that I can't imagine why anyone would ever want one.

But then again I'm almost brand new to the offroading club.

So far I have heard durability, travel, clearance, and ride quality. None of those are the primary reason why someone would want a solid front axle over IFS. The answer is articulation. An X fully locked vs a SFA vehicle fully locked will require a different driving style, but go damn near the same distance. The problem is these things don't come locked from the dealer...bastards. Anyway, articulation allows you to go through more demanding terrain when you have the open diff ailement as most of us do...boo hoo. When you are wheeling your X, when do you generally stop forward progress? I would say in many cases when the opposite ends of the truck are suspended or nearly suspended. (Yes there are a lot of other possibilities, but lets just focus on the IFS vs SFA aspect.)

Does a SFA ride worse, steer worse, have more unsprung weight than IFS? Yes. It is all a trade off. Long travel IFS is used in desert racing because it is more laterally stable. Articulation is less desirable at speed as it causes roll overs at speed. Hummers were made for the desert, for more speed related use than the old Jeeps. They are wide, and relatively low profile given their clearance. Can they crawl? Yes, but... They have the gearing, torque, but rely mostly on their lockers when the terrain really undulates. A military hummer has the following options in its TC:
HI = open diffs, open TC (front to rear).
Hi lock = open diffs, locked TC.
Neutral = duh.
Lo = low range, open diffs, locked TC.
Lo lock = low range, locked diffs, and locked TC.

I had a cherokee that I would take up this rutted and wildly articulating hill. I took off the rear sway bar, used momentum in spots, picked the lines of least required articulation, but could not climb the hill. I had the stock goodyear donuts on it at the time. My friend had MT's on his X and made it further up the hill. Not much further, but egg on my face at the time. Later, I made front swaybar disconnects, and promptly retested the hill using the same donut laden cherokee. It walked up the hill. I went back and chose a more demanding line, and again it walked up the hill. Articulation is king. Having said that, we took a hummer up the same hill. 37" goodyear MTs, low range, and we could not make it. We then simply lock the diffs and it walked right up.

Here is how I figure it, and then I will close this bandwidth disaster with this. You daily drive your X at least 80% of the time. Sometimes you let unwitting loved ones drive it at there peril. Why not have a vehicle that is safer on road for them, more stable, better handling, etc for the 80% of the time? Then simply turn on you selectable locker(s) when the going gets tough the limited amount of time you do spend off road? If you need any more offroad prowess than two lockers, tires, a lift, and skid protection can provide...you might consider building up a trailer queen instead. Food for thought.

Another advantage of articulation is stress on the driveline. Sure a fully-locked Xterra can go all kinds of places, but if it has a wheel or two lifted when things call for a lot of torque, you're focusing all that torque on just one side of the axle and inviting a CV or axle shaft to break. However if both wheels are getting grip, they're sharing the load and the stress isn't as focused.

And of course flex allows a vehicle to safely tackle terrain that would otherwise invite a rollover. It's safe to say that a non-SAS Hardbody would have rolled right over in this situation:



Brent

I'm surprised that one didn't flip right over with how little that front end is doing. The driver side tire should be stuffed in the wheel well instead of where it is, which is almost parallel to the chassis.

Of course offroad x is right about the stress. There are other reasons SFA is better in that one driving wheel (fully locked axle) only has one tires worth of traction. In some cases this is not enough traction to overcome the weight of the vehicle. I didn't want to put too much in as my last post was getting a tad bit long. I still think the X will be very capable with front and rear locked, despite IFS. Once you get past that level in wheeling, I wonder if it would have been better to buy something very street friendly, and have a second dedicated rig. Its hard if you are already dedicated to the X, and have commited the resources to get it modded as far as some have to go back.

going back to the comment on the H1 or as i know it the M998 HMMWV. it is a good vehicle for what we use them for in the army but as for "off roading" only the torque biasing diffs, portal axles with geared hubs, 37 or 36 in tires and good approach and departure angles make it great for mostly flat open terrain with few narrow roads. the old 6.2L diesel is a slug and the 6.5L isnt much better. there is almost no "flex" on the 998 while and old CUCV (chevy 1 ton with Dana 60's) has much more due to solid axles. as for the jeep versue xterra issue. we all have X's bought them knowing its shortcomings and live with them and still manage to have lots of fun. however i would take an XJ, or CJ any day of the week. oh well.