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did you happen to measure the distance from the center of your hub up the the bottom of the wheel arch before you lifted it ?
if so what was the measurement ?
if you didn’t can you go measure it as it is now and also measure the height of the blocks you installed ? ( we can subtract the block height from the current hub to fender height to determine how much you front springs have sagged) This is important because it adversely effects you alignment caster setting.
The spring doesn't look to be too sagged by way of distance between the bump stop and landing pad but I’ll guess it puts the before lift blocks measurement at 22 1/4” And then your caster at somewhere just south of 3.5* I’ll guess 3.1 on the driver side and 3.3* on the pass side.
did you happen to measure the distance from the center of your hub up the the bottom of the wheel arch before you lifted it ?
if so what was the measurement ?
if you didn’t can you go measure it as it is now and also measure the height of the blocks you installed ? ( we can subtract the block height from the current hub to fender height to determine how much you front springs have sagged) This is important because it adversely effects you alignment caster setting.
The spring doesn't look to be too sagged by way of distance between the bump stop and landing pad but I’ll guess it puts the before lift blocks measurement at 22 1/4” And then your caster at somewhere just south of 3.5* I’ll guess 3.1 on the driver side and 3.3* on the pass side.
I didn’t measure it but I can in the morning I’m at work now so I’ll post measurements in the morning. I was thinking caster too especially with the larger tires and added height.
”memory steer”
I think your steering g wheel is not returning to center because of low caster setting, normally 3.5* will allow for decent return to center but not with a dual steering stabilizer, so your “memory steer” is likely a combination of low caster and the dual steering stabilizer. There is zero reason a street driven truck with 34” tires requires dual steering stabilizer. Fwiw I run 37” MT tires and do not have a steering stabilizer even though my rig sees thousands of miles of off road driving a year.
Wander,
plain and simple it is caused by low caster. Your rear bar may be masking it a little bit but it isn’t the cure more caster is.
Bump steer.
true bump steer is caused when the track bar and tie rod are not parallel because each is moving in a different and separate arc from their respective pivot points the difference in those arcs is the amount of bump steer and forces the steering to move without input from the steering wheel. However you did not change the pivot points of either the track bar or the tie rod and are therefor are still using the factory steering geometry so if there is actually any bump steer it is exactly the same as every stock excursion and f250 has from the factory and while it was noted above that almost all vehicles have some bump steer the super duties are know to have any detrimental amount.
I think what you are likely experiencing when you hit a dip or pothole is simply poor handling cause by a soft front spring rate with stiff shocks and a stiff rear spring rate with soft shocks made all the worse by the rear anti sway bar and lower sidewalls on your tires due to the larger rims.
the fix, a simple test would be remove the dual steering stabilizer and go for a drive, if your wheel returns to center then bingo you know at least that part of the theory is correct, next step is get this alignment numbers to confirm.
I have tuned many Excursion with many different suspension and I strongly recommend 4.5* to 5.5* of caster.
if my guess is close on the hub to fender heights then you need new front leaf springs.
i guess we can cross that bridge when you measure but if you do that then you may as well do the rear because that is the other 1/2 of your problem and like I said in your suspension thread you need a lighter rear spring rate not stiffer like you did.
( which btw the 4600 Bilstein might be the right length for a 2” lift but totally the wrong shock for a higher spring rate.
Get the correct springs on your Ex and you will not need the rear sway bar which is added to your current problem even though it is sorta masking your wander.
I didn’t measure it but I can in the morning I’m at work now so I’ll post measurements in the morning. I was thinking caster too especially with the larger tires and added height.
larger tires actually require less indicated caster because the contact patch is further behind the axle center line which increases the effective caster angle.
”memory steer”
I think your steering g wheel is not returning to center because of low caster setting, normally 3.5* will allow for decent return to center but not with a dual steering stabilizer, so your “memory steer” is likely a combination of low caster and the dual steering stabilizer. There is zero reason a street driven truck with 34” tires requires dual steering stabilizer. Fwiw I run 37” MT tires and do not have a steering stabilizer even though my rig sees thousands of miles of off road driving a year.
Wander,
plain and simple it is caused by low caster. Your rear bar may be masking it a little bit but it isn’t the cure more caster is.
Bump steer.
true bump steer is caused when the track bar and tie rod are not parallel because each is moving in a different and separate arc from their respective pivot points the difference in those arcs is the amount of bump steer and forces the steering to move without input from the steering wheel. However you did not change the pivot points of either the track bar or the tie rod and are therefor are still using the factory steering geometry so if there is actually any bump steer it is exactly the same as every stock excursion and f250 has from the factory and while it was noted above that almost all vehicles have some bump steer the super duties are know to have any detrimental amount.
I think what you are likely experiencing when you hit a dip or pothole is simply poor handling cause by a soft front spring rate with stiff shocks and a stiff rear spring rate with soft shocks made all the worse by the rear anti sway bar and lower sidewalls on your tires due to the larger rims.
the fix, a simple test would be remove the dual steering stabilizer and go for a drive, if your wheel returns to center then bingo you know at least that part of the theory is correct, next step is get this alignment numbers to confirm.
I have tuned many Excursion with many different suspension and I strongly recommend 4.5* to 5.5* of caster.
if my guess is close on the hub to fender heights then you need new front leaf springs.
i guess we can cross that bridge when you measure but if you do that then you may as well do the rear because that is the other 1/2 of your problem and like I said in your suspension thread you need a lighter rear spring rate not stiffer like you did.
( which btw the 4600 Bilstein might be the right length for a 2” lift but totally the wrong shock for a higher spring rate.
Get the correct springs on your Ex and you will not need the rear sway bar which is added to your current problem even though it is sorta masking your wander.
Well the reason I went stiffer in the rear is because I tow a 8000 lbs travel trailer and thought it would help and that’s also the reason I added the sway bar cause a lot of guys recommended it to help with crosswinds and trailer sway control. So if I were to make the front stiffer by adding a leaf in the front would that equal things out and putting harder shocks in the rear?
Well the reason I went stiffer in the rear is because I tow a 8000 lbs travel trailer and thought it would help and that’s also the reason I added the sway bar cause a lot of guys recommended it to help with crosswinds and trailer sway control. So if I were to make the front stiffer by adding a leaf in the front would that equal things out and putting harder shocks in the rear?
post up a pic of your rear springs, If they are stock then the spring rate was 410 lbs inch, an 8000 pound trailer with 12% tongue weight would sag the rear 1.1” ......exactly as Ford designed. Your Ex would or should have been level with the trailer hooked up with stock spring rates.
Trailer sway
a rear hellwig bar despite the Internet’s misconception of their purpose does nothing for trailer sway. A correctly setup trailer hitch with proper weight distribution on the trailer is how you deal with trailer sway, If your trailer has more square footage of windage then the excursion has then you will want to look into a hitch that has a sway control mechanism built into it like a Hinsley Arrow.
Anyhow, I suspect at some point in the past somebody changed your front springs and my previous caster guess is null.
If you can get your current alignment specs we can go from there.
if you want to know if those front springs are stock get a measurement from the frame to the bump landing pad ( the blue distance between the red lines ) And post up.
Still no luck on the alignment specs called the ford dealer and once again they said they’d email them still nothing. Starting to think they don’t even have them. I got some pics of rear suspension and measurements on front.
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