Hello,
I have an '05 250 Super Duty and it has the over load spring in the rear. Is this really?

Russ

 

Really what?

Yes, superduties do have "overload" springs. I believe it is part of the camper package, but could also come in a towing package.

 

This is what I wanted to write.

 

Do you plan on installing a camper top or overloading the truck? If no, then no. Is there any reason you want to get rid of them?

 

I glad I got my overload spring, the 05 F250 CC PSD does not have much load capacity, put some weight in the back sinks right down onto the over load,hook up a trailer sinks right down to the overload. The overload saves it from sinking even further.

 

I wouldn't call it an overload spring. It's a helper spring. With a helper spring they can have a softer spring rate on the main spring pack until enoungh weight is on the springs to have the helper engage the blocks.

 

Yes , overloads are a good thing to have !!

 

I see the purpose of the overload, but my problem is this:
I do not drive the truck in a fully loaded condition. At highway speeds (70mph+), when I hit a bump or pothole, the rear axle teters (death teter) on the overload springs stops and will not stop unless the truck is coasted down in speed. I brought in into a Ford dealer and they told me that I did not have a problem, but I am almost positive that the combination of shock, spring, and shock placement are what is causing this issue.

The truck is a 2005 4x4 5.4L CC 7ft bed. The suspension is the non-FX4. Not sure if it matters with the options on the truck, but the truck came with a trailer hitch.

I swapped out the stock shocks with Bilstiens and it seems to have improved some of the control, but it does feel like it is capable of tetering. I remember reading on this forum and others that the reason the F150 was redesigned with regards to the rear shock placement was due to this reason, or at least an unstable rear axle; the shocks were relocated outwards towards the tire instead of towards the centerline. I also thought about removing the overloads, since I do not plan on really loading the truck. Also, after looking around at other SD years, the overloads were not installed on all trucks.

Is there a shock kit that can be installed towards the tire similar to the F150?

The truck is great with only this exception. I understand that this is a 3/4 ton truck and it was designed to haul.

 

Not sure what problem you believe to have. The springs are supposed to hit the stops on the frame during suspension travel. Is it the noise that is the problem?

 

It is not noise, but very hard bouncing like a teter totter or see-saw. For example, the right side will go up and hit the stop, come back down, while the left goes up and hits the stop; back and forth until the truck is stopped.. The result is loss of driveability and not too mention very dangerous.

 

Have you tried lowering your tire pressures? I run 50 psig front and rears when I am not loaded. Philip.

 

Welcome to the world of Heavy Duty trucks with a straight axle. This is a normal occurance and has been for many many years across all manufactures Heavy Duty trucks. A stiffly sprung vehicle will bounce around alot when it is empty. This truck will not drive and handle like a softly sprung car, with independent suspension and a 50/50 or 60/40 weight split.

As philips said, you can lower the air pressure in your rear tires when running empty and this will help some along with your Bilstien shocks.

But bottom line the truck is sprung to carry a heavy load properly. When you are running empty and on a rough road you May have to Slow down for the road conditions. This is normal, don't over drive the road conditions.
If you don't carry or pull heavy loads, and you want a better ride you may want to think about trading down to a 1/2 ton truck with a much softer suspension. The Super Duty's were meant to be used to carry or pull heavy loads.

Hope this helps

 

I understand the purpose of heavy duty trucks, but is it a common occurance to have a straight axle teter or see-saw like this (hitting the stops, back and forth)? This is not a complaint of harsh ride, or bounce, this is an axle that is out of control and does not stop unless the truck slows down.

 

Yes this is normal! And more than likely if you were riding along behind it you would see the rear wheels lose contact with the ground. 10 wheel dump trucks will do this on a rough road, and if the road is rough at a traffic light you will see skid marks in short choppy patterns with spaces between the marks where the rear wheels were in the air.

Also the rear end the truck can step out and move to one side or the other. This is do to the fact that the rear end is "loose" (in racing terms) do to the fact it is bouncing up and down and has lost traction with the road surface.

Don't know if you are familiar with racing but if you ever hear the term "Aero Loose" it is caused by a another race car coming up close behind you and taking the air (down force) off the rear of the car, causing the rear tires to lose grip with the road and then let the wild ride begin.

Hope this helps

 

I just added some timbren overload rubber springs on my F350 to take the place of the rubber bumper cusion. They really really help the side to side teeter totter effect. I dont' see how I'll ever touch the helpers again with a legal load. I had about 2000 - 2500 lbs on it the other week and it was still about an inch from touching the helpers. I think I need to take the 1/2" shim out of them though as it is rough riding due to the rubber springs riding on the bumper stops. My springs have some sag in them as the kit is designed for about 1/2 clearance between the rubber springs and the bumper stop steel.

You could also add a heavy torsion bar to the rear axle, but I don't think you want to remove the helper spring unless you replace it with some other type of helper.

Tony