Here is a link to my experience with lack of caster and loose steering which goes back to 2010. To highlight I quote:
"At highway speeds (with no disturbances) one should require only slight pressure changes with no tendency to wander. When there is too little caster there is actually a dead zone between left and right which we are describing as "loose steering"."


https://www.rv.net/forum/index.cfm/f...print/true.cfm

 

to be honest, on the Excursion the last thing I'd even touch would be the steering box.

From the factory the front and rear leafs are simply too weak for the weight of the rig. These leafs allow too much flex while cruising down the road. This amplifies any and all variations of the road and body movements.

My last X, and my current X can be driven with 1 hand (fingers really) with almost zero slop. Below is my list of items to fix/check and the order I'd perform.

1. tire pressure
2. Ball joints
3. Steering linkages
4. new leafs front and rear
5. steering damper
6. very very last...adjust the steering box

 

If you are going to claim that the Ford engineers used the wrong spring rate for the leafs then please share with us your idea of the correct spring rate ?

 

How's it going Brent?

Are the springs strong enough to hold the vehicle weight and perform tasks such as towing? Absolutely.

Are the springs too soft and deliberately designed to provide a "Soccer Mom" ride from the factory? Absolutely


This has been discussed ad nauseum in this forum for 15+ years. Many people have discovered that if your replace the leafs with Superduty leafs (not modified) you see better handling characteristics. I personally have done it twice. This 2000 and a 2002.





And yes, I absolutely think the front springs are utter garbage out the gate. F-250s don't have to deal with axle slap. You can read forums posts from early 2000's about this. And it just gets worse and worse with age. Superduty with a PSD occasionally see this after years and years of hard abusive duty. Not just pavement cruising like 99% of X's perform

 

Yeah I don't see why we need to provide engineering justification for different spring rates when we all know these trucks ride better with stiffer springs under them.

 

Do some 250/350 trucks have the same handling and steering complaints? Or more with excursion?

 

Brent was cheap and created reasons to back up his claims.

There's a huge difference between Brent and Camo's posting when it comes to backing up claims.

In this case I believe it's just a matter of semantics, intent, and specificity when it comes to a claim about Ford using springs too weak for the Ex.

They obviously weren't too weak, and while the end user (all of us) obtains what we feel is a general consensus that the suspension is much improved when we swap springs, the act of swapping to a "better" spring doesn't prove Ford used springs too weak for the Excursion.

Stewart

 

a simple answer of what spring rate you think is best was all I was looking for.

 

I like the V/mod B springs on my truck. They firmed up the ride quite a bit and got the handling issues under control, but aren't so firm that they bounce me around.

 

if we us the forums to educate ourselves on the engineering then people can modify their Excursions to suit their needs.

Ford engineers spec'ed a spring setup on the Ex to meet certain parameters, namely they wanted a lower ride height so they used a spring with less arch.
the factory spring rate is 380 lbs per inch front and 410 lbs in the rear and the springs have about 5" of wheel travel.

the f250 springs on the other hand have 8' of travel and depending on which of the 6 diffrent springs has anywhere from 350 to 410 while the rears have a 320/670 dual rate.

any of those springs can provide the same ride quality as a stock Ex since your ride quality is largely determined by the shocks.

the take away is that the Ex doesn't have "weaker" springs, they have springs with less arch. Less arch is going to give less wheel travel and when you have old worn shocks this is going to allow the Ex to bottom out onto the bump stop.

bottom line is "better handling" is not achieved from stiffer springs, it is derived from a combination of spring rate, wheel travel, shock tuning, and center of gravity.

the real challenge is defining what "better handling" means to you and selecting which components to use to achieve that. the best way I know of to do that is by understanding or "justifying the engineering"

 

My assumption was the 'spring rate' was already given by the suggestion of Ford truck springs. Choose the code that works for your situation.

 

yes they do.

excursions tend to have more wander complains then the F250 and that is attributed to the geometry of the flatter front leaf spring loosing caster when it sags, but the 250 springs sag just as much over time and plenty of F250's wander. The main culprit there is the wide margin of the caster spec ford uses.

loose steering,vibrations and death wobble is a common trait that is inherent in the design and components used on both the Ex and the F250

 

sure, but I see more time then not is people say Ex springs are weak use a stronger spring, then take the f250 rear spring and modify it to have the same spring rate as the stock Ex. usually they haven't put in a stronger spring they have installed a longer spring. which is great if that is what you wanted.

Knowing the rate and length we when can now modify the Ex to better suit our needs. Some may want increased payload, others may want altered ride heights, and other may want better on or off road handling traits while others are perfectly happy with the way ford designed it but need to fix some worn out parts.

 

^Agreed.

Although I've never been able to prove this, I suspect the Excursion spring eye bushings are softer than Super Duty. I think this adds to the issues that some folks talk about. I'm talking about spring eye bushings as delivered from the factory, not replacement.

 

Rob, it would not surprise me if this were true. A softer bushing would transmit less harshness which would result in a "better ride"

Anadotely, all the Excursion leafs I have taken off have had at least one bad bushing. Usually the front passenger which is also the side that the bump stop gets blown off first. Mostly because drivers naturally avoid hitting pot holes on the drivers side and are not as good at missing road hazards on the side with less visibility. Also why the right rear tire is the most common tire to get a flat.