Solid axle vs. IFS

[BPage]

Hey guys
I read forums all the time and hear people go back and forth on why they feel solid axles are better or why they feel IFS is better, but I have yet to hear anything concrete? can someone enlighten me to the pro's and con's with regard to expedition travel and light to medium exploration within the states?

I am not trying to open pandora's box, I am just looking for some solid facts one way or the other.


Note. I have a similar post on diesel vs gas engines...

Thanks in advance.
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[7wt]

There is no one better than the other all in all. On more technical trails a solid axle is going to give you more articulation and more importantly, constant and predictable ground clearance the entire way through. IFS changes ground clearance as the suspension compresses. This is most troublesome on hills that require a little more speed to carry you over, with speed comes more suspension compression and more chance of kissing a rock or something else you don't want to kiss. Another issue with IFS is trails with a crown in the center, any bit of compression will bring you closer to finding the ground. IFS are better for washboard roads, highway driving, high speed (or at least higher speed) dirt roads. Another plus side with IFS is they tend to not have as bad an issue with bumpsteer as the suspension geometry stays fairly constant through it's travel. Certain solid axles with leafs up front will have some bump steer that will walk you one way or another as the wheel goes up or down. This forces you to add corrective steering in the very place you want to keep your wheel straight. My take is to learn the limitations of what you drive and drive it. I have an IFS and despite it's limitations, I am happy with it's performance.

 

[chasespeed]

I have had both IFS, and solid axle rigs, and each has pros and cons as mentioned....

I think it comes down to personal preference, your rig, and intended use. My last 2 IFS trucks were a Rodeo, and a Trooper, both, very capable, easy to drive, etc...

BUT, my last 2 Solid Axle rigs, were a 7.3 Super Duty, and my current Cummins powered Ram... NEITHER of these rigs with IFS would be reliable, too heavy, and too much torque for IFS..

Chase

 

[93BLAZER]

If you ever want to "Lift" your vehicle a lift for an IFS vehicle usually is quite a bit more expensive than for a solid axle vehicle.

Also, you can get WARN manual hubs for your solid axle, and if you're not using 4x4, switch them to free spool and save a bit on gas mileage.

 

[ExplorerExplorer]

I prefer Ford's TTB system... As comfortable as a SLA system on road, with relatively identical performance off road to a solid axle...

 

[CJCA]

One of the advantages of a solid axle vs IFS is the solid axle is a simpler design with fewer, more robust parts and less likely to have problems out in BFE. They are easier to work on as well in most cases.

 

[Capt Sport]

Depends how you use your truck. I've had a solid axle Jeep and now have a IFS Chevy. While a solid axle is stronger than IFS, the IFS rides much better. And, if your burning up the road miles and not rock crawling, running rediculous sized tires/lifts for a true expo truck, or mud bog'n the IFS is a better choice IMHO. IFS is much more comfortable to ride in for hours at a time. However, if you are going to be doing serious offroading then go with the solid axle.

The way I use my truck is driving out to where I want to camp, and then exploring the rougher areas either on foot, mountain bike, atv or motorcycle. And, I eat up a lot of road miles getting where I want to go so IFS works better for me. That and I find it much easier and more secure to explore via atv or motorcycle, that way if I break something the truck is still in good shape to get me home as I explore solo most of the time.

 

[Wonderland]

I couldn't decide, so I have both on my truck.

IFS in the front, solid in the rear.:elkgrin:

 

[Desolation]

Application, application, application...
Specifying stock or near stock (OE) configuration.
Smooth terrain high speed (Highway) IFS.
Moderate terrain Moderate Terrain IFS/Solid
Rough terrain 'Road' Light load IFS/Solid
Rough terrain 'Road' Heavy load Solid
Rough terrain 'No Road' Solid.

Just my opinion. If modifications are factored in then I would change some of those positions and there are overlaps.

 

[jeepmedic46]

I have IFS on my Kj and love it. As was stated earlier you just have to learn the capabilities of your vehicle.

 

[78Bronco]

Front sump gaurd and skid plates are a necessity for an IFS truck to protect the motor, etc. Solid axle is more durable, less moving parts, no bumpsteer with proper steering/trac bar setup and has consistant ground clearance. Solid axles are made from steel while the newer IFS have an alloy axle housing which cracks & breaks under severe stresses. CV shafts limit wheel travel, lift kits are more $$$$ and offer little performance improvements over the stock setup.

Both have there pros and cons but overall I think a solid axle, sprung with coils and links has far more pros when compared to IFS.

 

[ntsqd]

As others have already said, to use should dictate the choice.

If going slow over really rough stuff is the use, then the solid axle makes more sense.

If going fast or even moderately fast down washboard roads is the dominate use then IFS (TTB or otherwise) makes more sense.

At the two extremes, the time and effort to make an IFS work well in crawling is significantly more than what it would take to make a solid axle work for this. The same time and effort to make a solid axle work well at speed, if put into an IFS, would see the IFS running away and hiding from the solid axle.

I've seen and been in both used at both extremes. I'm not saying that either can't be made to work in the others area of dominance, just to do yourself the favor of picking the more appropriate form for your use.

If you do choose IFS, know that a "lift kit" is NOT what you want. Those are for Mall Crawlers. You're looking for a suspension kit that increases wheel travel and may also have high quality damping included in the kit (you'll want that regardless). In older Toyotas that means Total Chaos, and it may also apply to Taco based rigs. In full sizes that used to, and may still, mean RCD.

 

[zimm]

I prefer Ford's TTB system... As comfortable as a SLA system on road, with relatively identical performance off road to a solid axle...

are we talking the twin i beams?

i thought it was great in theory. expensive to get even remotely close to aligned though. tire eaters, they are.

 

[zimm]

real world use dictates the prevalence of ifs. single use platforms are rare and expensive, and its easier to make an ifs more off road worthy, than it is to make a live axle more high speed road worthy. (ya really cant, truth be told). solids will be relegated to 3rd world markets (or hyper expensive limited production) if the heep becomes unprofitable.

crash testing is no friend to solid axles either.



that having been said. why do you think solid axles are still marketable in 3rd world nations (and Oz)?

 

[Scott Brady]

I am a fan of the solid axle. There is a reason why the Defender, 70 series, G-Wagen, etc. all still use that configuration. Of course the compromise is high-speed performance and comfort.

The newer Jeeps do a nice job of balancing both IMO.

I am not saying that IFS is inappropriate for long-distance, rough-road travel, as I had great luck with my Tacoma.

I just prefer the simplicity and robust nature of the beam axle on my trucks, for the same reason I like a manual transmission, transfer-case with a real shifter, etc. I just want fewer moving parts and better serviceability.