2010 Hyundai Sante-Fe 4cyl auto

[watkins]

Technically its a live/driven/powered solid axle. A solid axle refers to one in which the axle shafts do not have joints, regardless of whether it is powered or not.

[Shadow]

Technically its a live/driven/powered solid axle. A solid axle refers to one in which the axle shafts do not have joints, regardless of whether it is powered or not.

A true solid axle is one solid shaft from hub to hub. The axle in my 4Runner consists of two axle shafts connected to a differential. That's not a solid axle.

Here's a solid axle for you:

[theholycow]

I thought that "solid" in this context refers to the direct connection between the two wheels (not necessarily the part that transmits engine torque though; rather, the structural part); that is, non-independent.

[watkins]

Here's a solid axle for you:

Thats a solid non-driven axle.

I thought that "solid" in this context refers to the direct connection between the two wheels (not necessarily the part that transmits engine torque though; rather, the structural part); that is, non-independent.

Yes. Hence the need to classify between solid driven/live and solid non-driven.

[Rope-Pusher]

So now I gotta tell Uncle Joe and Aunt Velma that they were sitting in a cartoon vehicle.

One of the benefits of a live axle over a dead axle is that when you drive over an object, the differential is lifted as well, helping to keep the minimum ground clearance constant. If you don't drive over tree trunks and such, this benefit is largely lost. Yes, I drove my Cherokee over a telephone pole (the pole was laid on it's side, of course) just for grins - I could have entered the parking lot in an approved manner without too much extra effort. On the other hand, articulation of the suspension with a dead axle is typically superior, so maintaining traction and stability on uneven surfaces is better than with a live axle. Unsprung mass is also reduced with dead axles, which helps out on washboard roads and other uneven surfaces.

While some of the cute utes are criticized for not being durable enough, you can rip the wheels off of anything that's been built if enough speed is involved, since the energy of the collision between the wheel and a rock/stump is proportional to the square of the speed of the vehicle. If you buy an entry level Jeep vehicle, like the Patriot, you shouldn't expect it to be as durable as a Liberty, or the Liberty to be as durable as the Wrangler, but if you slow down they'll all be in one piece at the end of the trail. There isn't anything inherently stronger or weaker for a live or dead axle, or for a unibody vs BOF construction. It may be cheaper and easier to design a live axle hung on a set of leaf springs for a certain level of durability, and the same can be said for BOF construction, but that doesn't preclude there being a durable coil-sprung, dead axled, and unibodied vehicle. It just takes more engineering time and money to reap the benefits w/o sacrificing durability. You get what you pay for and you don't get what you didn't pay for, one way or the other.

[Shadow]

I thought that "solid" in this context refers to the direct connection between the two wheels (not necessarily the part that transmits engine torque though; rather, the structural part); that is, non-independent.

The term is "solid axle", not "solid axle housing". But like I said, people use the terms interchangeably. That doesn't make it correct though. Do some research and you'll find plenty of info out there on solid axles, live axles, straight axles, etc... Its mostly semantics and it doesn't really matter what you want to call it. My whole point is that the live rear axle in my 4Runner is inherently more heavy duty than a typical IRS that you get in most other SUVs these days.

[Shadow]

Here's a solid axle for you:

Thats a solid non-driven axle.

I thought that "solid" in this context refers to the direct connection between the two wheels (not necessarily the part that transmits engine torque though; rather, the structural part); that is, non-independent.

Yes. Hence the need to classify between solid driven/live and solid non-driven.

All solid axles are non-driven. Think about it. You see solid axles on trailers mostly. Anything from a small utility trailer to a large tractor trailer. People don't generally classify axles as driven or non-driven because that's obvious when they're part of a vehicle. There are really only two common axle configurations for most of the passenger vehicles on the roads today--IRS or live axle.

[Shadow]

So now I gotta tell Uncle Joe and Aunt Velma that they were sitting in a cartoon vehicle.

One of the benefits of a live axle over a dead axle is that when you drive over an object, the differential is lifted as well, helping to keep the minimum ground clearance constant. If you don't drive over tree trunks and such, this benefit is largely lost. Yes, I drove my Cherokee over a telephone pole (the pole was laid on it's side, of course) just for grins - I could have entered the parking lot in an approved manner without too much extra effort. On the other hand, articulation of the suspension with a dead axle is typically superior, so maintaining traction and stability on uneven surfaces is better than with a live axle. Unsprung mass is also reduced with dead axles, which helps out on washboard roads and other uneven surfaces.

While some of the cute utes are criticized for not being durable enough, you can rip the wheels off of anything that's been built if enough speed is involved, since the energy of the collision between the wheel and a rock/stump is proportional to the square of the speed of the vehicle. If you buy an entry level Jeep vehicle, like the Patriot, you shouldn't expect it to be as durable as a Liberty, or the Liberty to be as durable as the Wrangler, but if you slow down they'll all be in one piece at the end of the trail. There isn't anything inherently stronger or weaker for a live or dead axle, or for a unibody vs BOF construction. It may be cheaper and easier to design a live axle hung on a set of leaf springs for a certain level of durability, and the same can be said for BOF construction, but that doesn't preclude there being a durable coil-sprung, dead axled, and unibodied vehicle. It just takes more engineering time and money to reap the benefits w/o sacrificing durability. You get what you pay for and you don't get what you didn't pay for, one way or the other.

Years ago I saw the Flintstone Flyer at Universal Studios in Orlando. No, it wasn't a cartoon, but of course it was based off the cartoon. LOL

You're correct about your IRS vs live axle vs unibody vs ladder frame assessment. However, you seem to be missing my point. I don't use speed to pull stumps, I use force. Torque multiplication (in low gear) combined with traction from four wheels is what I need to do something like pull a stump out of the ground. I'm sure you'd agree that a fully boxed frame and live axle are more suited to this kind of force than a unibody vehicle with IRS. And that's my whole point--I use my vehicle as a workhorse. I'd never even attempt that kind of stuff in a vehicle that didn't have a true frame and a live axle in the rear.

If you think there are any unibody vehicles out today with a chassis as strong as a fully boxed ladder frame, you should name them. I'd be interested to hear your opinion. There's a good reason why fullsize pick-ups like the Ford Super Duty are still body-on-frame vehicles. Years ago, Jeep came up with the "uniframe" chassis, which was basically a typical unibody chassis with frame rails welded on to the bottom. The whole purpose of doing this was because Jeep engineers realized that the unibody chassis wasn't strong enough to cope with some of the stresses that these Jeeps would endure. It's still a compromise though and everyone knows that it's better than a regular unibody chassis, but not as strong as a ladder frame.

[Rope-Pusher]

^ Having a body on frame construction doesn't denote a specific level of strength. I'm sure brand A's frame is stronger than brand B, but the one that brand C is coming out with next year will be stronger yet, but the ones in some little pick-em-ups coming out of India or China are like cooked pieces of pasta. I just don't believe that there are any strength limitations with unibody designs. They may actually be stiffer and stronger than some BOF constructions, owing to the added framing being welded directly to the unibody rather than just being bolted to the body through isolators. Solidly mounted as such, the frame rails strengthen the unibody and the unibody strengthens the frame rails and the net strength and stiffness is greater than either alone could have provided. Specific to stump pulling or snow plowing, trailer hitch and suspension attachment loads can be fed into rails welded to the unibody in such a way that the loading is spread over a wide area. Folks have been drag racing with unibody muscle cars for years and as the power levels go up they find ways to add to the structure to make them live without the trouble of throwing a full frame under them.

[Shadow]

^ Having a body on frame construction doesn't denote a specific level of strength. I'm sure brand A's frame is stronger than brand B, but the one that brand C is coming out with next year will be stronger yet, but the ones in some little pick-em-ups coming out of India or China are like cooked pieces of pasta. I just don't believe that there are any strength limitations with unibody designs. They may actually be stiffer and stronger than some BOF constructions, owing to the added framing being welded directly to the unibody rather than just being bolted to the body through isolators. Solidly mounted as such, the frame rails strengthen the unibody and the unibody strengthens the frame rails and the net strength and stiffness is greater than either alone could have provided. Specific to stump pulling or snow plowing, trailer hitch and suspension attachment loads can be fed into rails welded to the unibody in such a way that the loading is spread over a wide area. Folks have been drag racing with unibody muscle cars for years and as the power levels go up they find ways to add to the structure to make them live without the trouble of throwing a full frame under them.

I'm not trying to say that a unibody frame can't be built up to handle more stress. Speaking of drag racing, subframe connectors were a popular mod back in my old 5.0 Mustang days. Why? Simple--the chassis needed them when you got up in HP and started using sticky tires. Guy could really do some damage to the unibody chassis.

But still, lets use some common sense here. Every heavy-duty truck is built BOF. Why exactly do you think that's true? Have you ever seen a fullsize truck with a unibody chassis? A fully boxed ladder frame is inherently stronger than a unibody chassis, ceteris paribus. That's not really even debatable. C-channel ladder frames are even stronger than unibody. I suspect you already know this, but for some reason you're posting replies that skirt around the issue without addressing the facts. I can't quite figure out if you have an agenda here or if you're just looking to make conversation. If you want to get into a more technical discussion on frame/chassis structure, I'll be happy to continue chatting with you. If so, lets talk in more definitive terms instead of generalizing.

[Rope-Pusher]

^ Having a body on frame construction doesn't denote a specific level of strength. I'm sure brand A's frame is stronger than brand B, but the one that brand C is coming out with next year will be stronger yet, but the ones in some little pick-em-ups coming out of India or China are like cooked pieces of pasta. I just don't believe that there are any strength limitations with unibody designs. They may actually be stiffer and stronger than some BOF constructions, owing to the added framing being welded directly to the unibody rather than just being bolted to the body through isolators. Solidly mounted as such, the frame rails strengthen the unibody and the unibody strengthens the frame rails and the net strength and stiffness is greater than either alone could have provided. Specific to stump pulling or snow plowing, trailer hitch and suspension attachment loads can be fed into rails welded to the unibody in such a way that the loading is spread over a wide area. Folks have been drag racing with unibody muscle cars for years and as the power levels go up they find ways to add to the structure to make them live without the trouble of throwing a full frame under them.

I'm not trying to say that a unibody frame can't be built up to handle more stress. Speaking of drag racing, subframe connectors were a popular mod back in my old 5.0 Mustang days. Why? Simple--the chassis needed them when you got up in HP and started using sticky tires. Guy could really do some damage to the unibody chassis.

But still, lets use some common sense here. Every heavy-duty truck is built BOF. Why exactly do you think that's true? Have you ever seen a fullsize truck with a unibody chassis? A fully boxed ladder frame is inherently stronger than a unibody chassis, ceteris paribus. That's not really even debatable. C-channel ladder frames are even stronger than unibody. I suspect you already know this, but for some reason you're posting replies that skirt around the issue without addressing the facts. I can't quite figure out if you have an agenda here or if you're just looking to make conversation. If you want to get into a more technical discussion on frame/chassis structure, I'll be happy to continue chatting with you. If so, lets talk in more definitive terms instead of generalizing.

Until you have data in your hands, it's all generalizing. There is nothing inherently stronger about a BOF construction. Either design can be built to whatever level of strength and stiffness you desire. The old Durango was BOF. The new one is a unibody on roids. To make any claims about one vs the other without having experience in the structural analysis of each particular one is just a swag. Did the old Durango have a SOTA hydroformed HSS frame? What was the gage of the steel? What were the section dimensions of the rails? How were the longitudinal and lateral rails joined? Does the new Durango have an equivalent frame welded to a well-designed unibody? If they were both successfully designed to the same criteria they would be functionally equivalent. It's like debating whether 4 wheel disks are better than disk-drum brake systems without looking at how well each was designed to perform, or like saying overhead cam motors are superior to cam in block motors.

[theholycow]

Gotta agree with Rope-Pusher here. The reasons that pickups are BOF do not necessarily include hard design limitations on unibody, but rather:
- There exists no reason for a pickup NOT to be BOF, unlike a car/small SUV/minivan.
- The engineering, lab testing, and real-life market testing has already been done so it doesn't need to be done again.
- Marketing...nobody's going to buy a unibody pickup!
- Modularity: Pickups are offered without the bed as chassis-cab trucks for custom truck outfitters. Utility bodies, dump bodies, etc; then in bigger trucks, EVERYTHING comes from the manufacturer as a chassis-cab and gets its box from another company.

The marketing and modularity issues aren't soft issues that you can work around, they are absolute.

Those reasons are just off the top of my head.

[watkins]

- Modularity: Pickups are offered without the bed as chassis-cab trucks for custom truck outfitters. Utility bodies, dump bodies, etc; then in bigger trucks, EVERYTHING comes from the manufacturer as a chassis-cab and gets its box from another company.

The marketing and modularity issues aren't soft issues that you can work around, they are absolute.

Oh yeah. We have a few 2011 Ram 5500 chassis-cabs hanging around the lot from time to time. My favorite part: all of the ones that have come through have manual transmissions.

[Shadow]

Until you have data in your hands, it's all generalizing. There is nothing inherently stronger about a BOF construction. Either design can be built to whatever level of strength and stiffness you desire. The old Durango was BOF. The new one is a unibody on roids. To make any claims about one vs the other without having experience in the structural analysis of each particular one is just a swag. Did the old Durango have a SOTA hydroformed HSS frame? What was the gage of the steel? What were the section dimensions of the rails? How were the longitudinal and lateral rails joined? Does the new Durango have an equivalent frame welded to a well-designed unibody? If they were both successfully designed to the same criteria they would be functionally equivalent. It's like debating whether 4 wheel disks are better than disk-drum brake systems without looking at how well each was designed to perform, or like saying overhead cam motors are superior to cam in block motors.

You keep saying that unibody “can” be built just as strong as BOF and I’m not arguing that. Anything can be built (or overbuilt) to be stronger than necessary. That’s not the point here….the fact of the matter is that unibody vehicles are not built as strong as a fully boxed BOF chassis. Hmm….how can I prove that to you? Well, I guess it’s impossible to prove without having access to the specifications of each and a structural analysis. So lets use the next best thing—logic. I’ve said several times already that all heavy-duty work vehicles are still BOF. So far you haven’t denied that, but you continue to ignore it. So tell me, why would anyone bother to still build BOF vehicles in this day and age if strength and longevity weren’t an advantage?

Lets consider fullsize pick-ups that were built for work. They are used as plow vehicles, tow vehicles, and to haul heavy loads. And they are BOF, every last one of them. If it made sense to manufacture them with unibody chassis, someone would have done it by now. After all, unibody does have its advantages in these days of CAFE.

Lets talk about Jeeps. Why is it that Jeep’s #1 offroad vehicle still uses BOF construction? Why not make it unibody? Hint: BOF can handle the stresses of offroading better than unibody, and Jeep knows that the Wrangler, on average, will spend much more time offroad than any other Jeep vehicle.

Okay, forget the Wrangler…lets talk about the Grand Cherokee. Why do you think Jeep engineers decided to weld rails onto the bottom of the unibody chassis and call it a “uniframe” chassis? Do you think they felt that the typical unibody chassis needed to be strengthened, so they came up with a cost effective way to do that while sticking with the unibody chassis? Or do you think it was just unnecessary and nothing but marketing hype to please the people who wished for BOF construction?

Have you ever noticed that a vehicle’s tow rating typically goes down when it moves from BOF to unibody? Look it up….there are plenty of examples of SUVs that were once BOF and now are unibody. Why would the tow rating be lower if the unibody chassis was just as strong? Even when the engines aren’t downgraded, the tow rating still goes down. Why is that?

[Shadow]

Gotta agree with Rope-Pusher here. The reasons that pickups are BOF do not necessarily include hard design limitations on unibody, but rather:
- There exists no reason for a pickup NOT to be BOF, unlike a car/small SUV/minivan.
- The engineering, lab testing, and real-life market testing has already been done so it doesn't need to be done again.
- Marketing...nobody's going to buy a unibody pickup!
- Modularity: Pickups are offered without the bed as chassis-cab trucks for custom truck outfitters. Utility bodies, dump bodies, etc; then in bigger trucks, EVERYTHING comes from the manufacturer as a chassis-cab and gets its box from another company.

The marketing and modularity issues aren't soft issues that you can work around, they are absolute.

Those reasons are just off the top of my head.

I’m sorry, but your first three points are all very weak. Here’s why: Think about the reason cars went from BOF to unibody in the first place. You do realize that even most passenger cars were built with BOF construction years ago, right? It should be obvious to you that unibody has several distinct advantages. These advantages would apply equally to a small car or a large pick-up. So to say that there’s no reason for a fullsize pick-up to NOT be BOF is just silly. The reason unibody never made it to large pick-ups is because they aren’t strong enough to cope with the stresses that those vehicles are built to endure. If the unibody chassis was built just as strong, it would surely be in use by now on large pick-ups and work trucks, simply because of the other advantages inherent of the design.

You talk about engineering and testing….do you really think nothing has been done in terms of engineering/testing for a pick-up frame? Seriously? I can assure you that the BOF chassis has been updated over the years….it’s not like nothing has changed in the last 20-25 years. LOL. Marketing—nobody will buy a unibody pick-up. That’s probably an accurate statement. But think about the reason why nobody would buy one. If anyone thought a unibody pick-up would hold up, I’m sure they’d be more than happy to buy one. The fact that manufacturers don’t make unibody pick-ups just reinforces public perception that a unibody pick-up wouldn’t last very long. Can manufacturers actually build a unibody chassis that would be suited for a fullsize pick-up? Absolutely. So why don’t they do it then? Simple answer—cost. Imagine what it would cost to build that kind of heavy duty unibody chassis. My guess is that it simply wouldn’t be cost effective.

Modularity—this is very true. It’s easy to configure different bed/cab set-ups with BOF construction. You still have to consider SUVs though….up until recently, there were plenty of SUVs built BOF. Do you know why? I’ll give you a hint: Many SUVs were derived from pick-up trucks, and pick-up trucks were built BOF. Today, the SUV is in a different place, slowly moving more towards car-based than truck-based. Vehicles like my 4Runner are still a stand-out, still built strong like the older versions. And that’s why I can do things with my 4Runner that I wouldn’t even think about doing with a unibody SUV. I have no doubt that the day will come when no new SUV will have BOF construction. And when that day comes, people will have no choice but to go with a BOF pick-up when they need to use a vehicle as a workhorse.