High Altitude Gladiator for highway use?

[Wheelin98TJ]

Coil springs are better. But they still work the same way as leaf springs. (Go drive a F150 with leaf springs, it rides far better than a jeep). Spring rates affect ride hugely. (spring rate is essentially how many lbs it takes to compress the spring a given distance. typically lbs per inch.)

When you hit a bump while driving, how much the suspension compresses depends on 2 factors.

1) spring rate - the bump generates an upward force into the spring. the lower the spring rate, the more the suspension will deflect for the bump.
2) Compression damping - this is how hard the shock absorbers resist upwards movement (compression). Shocks have a separate value which is rebound damping. Which is how much the shocks resist the suspension extending or rebounding.

The voodoo of suspension tuning is selecting spring rates, compression damping and rebound damping that matches the conditions and vehicle requirements.

Coils don’t work the same way as leafs at all. There are good reasons leafs are going away and coils are replacing them. I agree coils are better.

I have a 2020 F150 that has 22k miles on it and it replaced a 2010 F150 I put 190k on. I know how those drive and ride. And they do ride and drive nice.

Springs do not deflect bump. Shocks do that. Take a ride with no shocks and see how soft and uncontrolled it is.

There’s no voodoo with spring rates. You get it close and pick the spring that gives the height you want. If it sags, replace it.

Shocks make more difference than springs when it comes to how you feel the ride. I can’t repeat this enough.

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[UTRZRDOG]

Sold a Platinum Tundra to purchase the Rubicon Diesel. As far as ride the Tundra rode better and was quieter driving down the road at 80 mph but the Gladiator is funner and easier to get around town in and easier parking at the stores. If I were going on a 2000 mile road trip I wouldn’t have any problem taking the Gladiator in that 26 MPG vs 16 MPG is worth a bit of a loss in ride. In my opinion the biggest difference is the available room in the Jeep vs the tundra. The Tundra Crewmax is amazing for the rear seat passenger compared to the Gladiator but still the Gladiator is not bad. We also have a Lexus RX450 Hybrid that gets 28-30 MPG. Since we purchased the Diesel Gladiator we still take the Gladiator on road trips more often in that it is cheaper to drive since the RX require’s Premium fuel that is .30 more per gallon in our area. Not only that, if we see a mountain road we want to take, off we go. Don’t be scared of the Gladiator and the diesel is just and added bonus in my opinion. Good luck with your decision and if you get the Gladiator I am sure you will be very happy with it! The High Altitude looks like one sweet ride.

 

[ShadowsPapa]

As far as space - my daughter-in-law made the comment shortly after getting into the back seat of my JT "wow, this has a lot more room in it". She was thinking of my Silverado. My son, over 6', said the same thing. Plenty of leg room, more roomy back seat.

 

[Aonarch]

Late to the party, but I drove my lifted Gladiator on 35s, on a 5,000 mile trip and it was fantastic. I get zero wander and can easily one finger drive.

When people complain about the wander, I wonder, how is there alignment, what kind of tires, what tire pressure, how is the tire wear? Then ultimately adding the Mopar extended LCAs for ~$60 will add caster, helping highway feel.

 

[Wheelin98TJ]

I'm interested in links.
I will also go through my college suspension books to refresh things.

Check out posts from mrblaine who is the mind behind Savvy Off-Road and owner of Black Magic brakes. He is a suspension, steering, and brakes genius.

Not a suspension thread, but shock talk from mrblaine in posts #104 and beyond:
https://www.jeepforum.com/forum/f9/2003-wrangler-alignment-4331385/index3.html

Coil spring thread:
https://www.jeepforum.com/forum/f9/coil-springs-4324027/

Fox shocks thread (post #60 starts the talk about springs):
https://www.jeepforum.com/forum/f9/any-fox-tuners-east-mississippi-4196514/

Here is what Blaine builds:

https://www.jeepforum.com/forum/f9/everyone-critic-critique-one-627417/

https://www.jeepforum.com/forum/f9/everyone-critic-critique-one-ii-4325633/

 

[MPMB]

Leaf springs and coil springs, for the purpose of automotive suspension, do, in fact, perform the same thing. They carry the weight of the vehicle and absorb weight transfer.

The benefit of coil springs is the weight and space. It's a fraction of what a leaf spring weighs.

Shocks control the rate of velocity the weight (through inertia) transfers and spring oscillation during suspension travel.

Ride "harshness" is usually when the shock is in high-speed travel. The speed is relative to the shock, not mph. The shock is compressing or rebounding at, say 3" per second or greater. Back when we dyno'd shocks, we did 1"/second, 2"/second, and 3"/second for our builds. Translated to road usage, high-speed travel would be hitting a pothole at any mph, a big limb across a forest service road, or the landing after cresting a big rock.

Shocks can make the ride seem harsh if high-speed travel is far stiffer than the spring rate. For example (just pulling #s out), a 350# spring is paired with a shock that has a valving of 1200#/inch @ 3" travel/second. That's going to feel far harsher than a 350# spring with a shock that's valved at 400#/inch @ 3" travel/second.

In racing, shocks are handling a lot more of the heavy lifting in the suspension package, while springs are there just to keep the car off the ground. Lateral weight transfer is controlled by the swaybar. When I got out, cars were running 125# springs upfront with ~2" swaybars. 10 years earlier everyone was running 325#-350# springs and 1.125" bars.

It all does the same thing. In fact, there was a mathematical equation that calculated the effective rates of the springs and swaybars and spat out a number. iirc, that was the roll couple distribution.

I plugged the numbers in comparing the "old" suspension packages and the new packages. The numbers came out almost the same.

 

[Wheelin98TJ]

Leaf springs and coil springs, for the purpose of automotive suspension, do, in fact, perform the same thing. They carry the weight of the vehicle and absorb weight transfer.

The benefit of coil springs is the weight and space. It's a fraction of what a leaf spring weighs.

Shocks control the rate of velocity the weight (through inertia) transfers and spring oscillation during suspension travel.

Ride "harshness" is usually when the shock is in high-speed travel. The speed is relative to the shock, not mph. The shock is compressing or rebounding at, say 3" per second or greater. Back when we dyno'd shocks, we did 1"/second, 2"/second, and 3"/second for our builds. Translated to road usage, high-speed travel would be hitting a pothole at any mph, a big limb across a forest service road, or the landing after cresting a big rock.

Shocks can make the ride seem harsh if high-speed travel is far stiffer than the spring rate. For example (just pulling #s out), a 350# spring is paired with a shock that has a valving of 1200#/inch @ 3" travel/second. That's going to feel far harsher than a 350# spring with a shock that's valved at 400#/inch @ 3" travel/second.

In racing, shocks are handling a lot more of the heavy lifting in the suspension package, while springs are there just to keep the car off the ground. Lateral weight transfer is controlled by the swaybar. When I got out, cars were running 125# springs upfront with ~2" swaybars. 10 years earlier everyone was running 325#-350# springs and 1.125" bars.

It all does the same thing. In fact, there was a mathematical equation that calculated the effective rates of the springs and swaybars and spat out a number. iirc, that was the roll couple distribution.

I plugged the numbers in comparing the "old" suspension packages and the new packages. The numbers came out almost the same.

I agree with just about everything here, but I don't agree coils and leafs serve the same purpose for suspension.

Leafs locate the axle, coils do not.

 

[MPMB]

I agree with just about everything here, but I don't agree coils and leafs serve the same purpose for suspension.

Leafs locate the axle, coils do not.

Coil spring.
Leaf spring.

I specifically stated "for suspension purposes." I did not say mechanical or geometry. Don't try to pull some minutia of semantics which is irrelevant to the discussion to avoid saying you're wrong.

The function that a leaf spring performs in locating the axle is not pertinent.

 

[Wheelin98TJ]

Coil spring.
Leaf spring.

I specifically stated "for suspension purposes." I did not say mechanical or geometry. Don't try to pull some minutia of semantics which is irrelevant to the discussion to avoid saying you're wrong.

The function that a leaf spring performs in locating the axle is not pertinent.

Locating the axle is the job of the suspension.

I'd never say " Leaf springs and coil springs, for the purpose of automotive suspension, do, in fact, perform the same thing ", but if you think it's somehow accurate, carry on.

 

[Capricorn]

The Overland is meant for the road more than any other trim. It's still capable offroad but is build more for on-road than any of the others. You may also look for a Mojave as many who have those in the forums have expressed how much nicer the driving dynamics are, just keep in mind that the softer suspension gives up quite a bit in some trails/rocky terrain for that squishy suspension.

As a Mohave owner, I attest to this - it is the most comfortable Jeep on the pavement. I don't know how it compares to the Tundra, but I found it equal to, if not better than a Tacoma I test drove a few months ago in the way it handles rough asphalt or street/highway irregularities like small potholes, bumps etc.

 

[Gvsukids]

What was a thread about a trim package, turned into a hijacked thread on suspension.

 

[dcmdon]

Coils don’t work the same way as leafs at all. There are good reasons leafs are going away and coils are replacing them. I agree coils are better.

I have a 2020 F150 that has 22k miles on it and it replaced a 2010 F150 I put 190k on. I know how those drive and ride. And they do ride and drive nice.

Springs do not deflect bump. Shocks do that. Take a ride with no shocks and see how soft and uncontrolled it is.

There’s no voodoo with spring rates. You get it close and pick the spring that gives the height you want. If it sags, replace it.

Shocks make more difference than springs when it comes to how you feel the ride. I can’t repeat this enough.

You can repeat it all you want. But you are still wrong.

The main difference between leaf springs and coil springs other than packaging is that leaf springs have a fair amount of internal friction from the leaves rubbing against each other as they compress. So they actually add a bit of unpredictable damping to the springing.

Its better to leave the damping to the dampers.

S;rings of course deflect when you hit a bump. When the suspension is in compression like when you hit a bump there are TWO components resisting the movement. 1) the springs - this is determined by the lbs of force per inch rating of the spring. 2) The shocks. This is determined by the valving on the compression side of the shocks.

Take a ride with no springs and you will find it to be a very short ride because the tires are hard against the fenders.

The fact that you don't understand the magic / voodoo / art / science of balancing spring and damping rates tells me that you are ignorant of this to the point that you don't know what you don't know.

Entire companies have been built on their ability to blend spring rates with just the right compression and rebound damping rates.

Its so Voodoo that car companies will drag a prototype halfway around the world to the Nürburgring to do suspension tuning. (which also includes roll bar, tire, and bushing stiffness, which we aren't discussing here).

Here's a great article on some of the complexities of damper tuning specifically, but it discusses the interplay between springs and dampers.

http://www.theoryinpracticeengineering.com/drift_mag/basic_damper.pdf

 

[dcmdon]

I drove my F250 4x4 (and hd suspension) to Kansas to pick up an antique engine and engine trucks (the cart the engine would be mounted on for transport).
The engine weighs 2,000 pounds. The trucks - I'm thinking 200+ at least.
The winch truck that loaded the engine into my truck literally had the front wheels off the ground to lift the engine high enough for me to back under it.
Anyway, my truck loaded up, me, my wife and my wife's aunt all headed back to Iowa - everyone commented how wonderfully that truck rode. Barbara's aunt commented "this rides like a Cadillac" and it was on the leaf spring overloads.
On the way TO Kansas was a very different story - rough, bumpy, sort of like a truck I guess.

How about the mass of unsprung components -

**I know you know this. I'm just adding for others who may not know

That's typical of "work trucks". Not trucks ike a Gladiator or F150 that has little more cargo capacity than my wife's Volvo wagon. (no joke).

As you know REAL trucks have stiff rear springs that make for a crappy ride when empty. Ha. They need it to prevent the rear from squatting too much when weight is put in back.

Re unsprung weight.

The ratio of sprung to unsprung weight determines how well a wheel can track the road. If the sprung weight on the rear corner of a truck is 1000 lbs and the wheel/tire weighs 100 lbs, then the suspension can accelerate the wheel downwards with a force of 10G to track the road.

Add an engine to the back of the truck and now there is 1500 lbs. The suspension can now accelerate the wheel down at 15g.

That ratio is actually one of the reasons that big heavy cars have always ridden better. Their ratio of sprung weight to unsprung weight was higher.

 

[Wheelin98TJ]

You can repeat it all you want. But you are still wrong.

The main difference between leaf springs and coil springs other than packaging is that leaf springs have a fair amount of internal friction from the leaves rubbing against each other as they compress. So they actually add a bit of unpredictable damping to the springing.

Its better to leave the damping to the dampers.

S;rings of course deflect when you hit a bump. When the suspension is in compression like when you hit a bump there are TWO components resisting the movement. 1) the springs - this is determined by the lbs of force per inch rating of the spring. 2) The shocks. This is determined by the valving on the compression side of the shocks.

Take a ride with no springs and you will find it to be a very short ride because the tires are hard against the fenders.

The fact that you don't understand the magic / voodoo / art / science of balancing spring and damping rates tells me that you are ignorant of this to the point that you don't know what you don't know.

Entire companies have been built on their ability to blend spring rates with just the right compression and rebound damping rates.

Its so Voodoo that car companies will drag a prototype halfway around the world to the Nürburgring to do suspension tuning. (which also includes roll bar, tire, and bushing stiffness, which we aren't discussing here).

Here's a great article on some of the complexities of damper tuning specifically, but it discusses the interplay between springs and dampers.

http://www.theoryinpracticeengineering.com/drift_mag/basic_damper.pdf

Go ahead and swap springs to change how soft or firm your Jeep rides.

I'll do it with shocks like the smart guys do.

P.S. If your tires are against the fenders without shocks, your bumpstops are set wrong. This is suspension 101.

 

[ShadowsPapa]

Max tow springs are a good inch+ SHORTER than the factory Overland springs.
Overland springs are definitely softer - lower rate, than max tow.

When I swapped springs and sat the truck back down on the floor - the truck sat about the same. The curb height was basically unchanged - but - the ride was changed - it's stiffer and doesn't stick to the road in rough conditions like it did with the stock Overland springs. That's because lower spring rates allow the tire to be kept against the road better.
So I gained no height, I lost no height, I changed the ride characteristics and I made the truck stick to the road less with the higher spring rate. But it doesn't sag as much under heavy load. I gave up rough road stability to get cargo carrying.

Bottom line - same exact ride height, bumpier ride, not as stable on railroad tracks and washboard roads.

Rubicon springs, GENERALLY SPEAKING" are a soft ride for the articulation needed and to keep the tires stuck to the ground under rough conditions - responding to rocky and rough ground. But they are a bit longer to compensate for the added weight of the Rubicon (and other reasons)

I'd really set things on fire if I posted clips from my college suspension tech books........... and the links I have when our internet is back up and I'm not tethered to a phone sitting up at the peak of the 2nd story of my shop building 30' in the air.
A tidbit from one of the older books "torsion bars are true springs".......... the books were written by automotive engineers with content supplied by Ford, GM and Chrysler.
My 70 Javelin front springs (yes, COIL springs) - the "go pack" springs were heavier springs. If I had wanted to put new stock springs under it - there was roughly 1 page of springs to choose from. Car always sat at the same height so it wasn't a matter of raising or lowering it - it was for changes in the ride and for turning for different purposes. Shocks were all the same.
My parts books reveal that there were more spring options for cars in the 60s through 80s than almost any other part. Page after page of springs. Some models had full pages of various springs. And it wasn't all based on the engine or AC vs non-AC.
We're not that far off with the Gladiator - the number of springs used under these trucks is pretty impressive. And yet - other than trim level differences, the shocks are the same. Rubicon - all got the same shocks regardless of spring. Overland - same shocks regardless of springs used.

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