Our 2004 E450 28 Foot handled terrible until we added additional + Caster to the front wheels.
The Ford Spec for front end CASTER is:
LH +1.3 to +6.8 Degrees
RH +1.8 to +7.3 Degrees
Our unit was:
LH +3.3 Degrees
RH +3.5 Degrees
We added + 2.0 degrees, so we are now at:
LH +5.3 Degrees
RH +5.5 Degrees.
Alignment problems on the E series follow the 80/20 rule in the sense that TOE and CAMBER is 20% of the story while CASTER is 80% of the story. TOO LITTLE CASTER will amplify any external force many fold to the detriment of stability.
If your unit feels like the steering box needs to be tightened up it is because of TOO LITTLE + CASTER.
If cross winds and wind gusts cause havoc it is because of TOO LITTLE + CASTER.
If you think the tail is wagging the dog it is because of TOO LITTLE + CASTER.
If you are needing to drive it all day and never relax it is because of TOO LITTLE + CASTER.
If your unit drives GREAT, like an SUV, it is because you have a proper amout of + CASTER which I am guestimating to be about +5.0 degrees or more. (Note: The RH caster is always more then LH (CROSS CASTER = LH - RH))
The Ford Spec for front end CASTER is:
LH +1.3 to +6.8 Degrees
RH +1.8 to +7.3 Degrees
Our unit was:
LH +3.3 Degrees
RH +3.5 Degrees
We added + 2.0 degrees, so we are now at:
LH +5.3 Degrees
RH +5.5 Degrees.
Alignment problems on the E series follow the 80/20 rule in the sense that TOE and CAMBER is 20% of the story while CASTER is 80% of the story. TOO LITTLE CASTER will amplify any external force many fold to the detriment of stability.
If your unit feels like the steering box needs to be tightened up it is because of TOO LITTLE + CASTER.
If cross winds and wind gusts cause havoc it is because of TOO LITTLE + CASTER.
If you think the tail is wagging the dog it is because of TOO LITTLE + CASTER.
If you are needing to drive it all day and never relax it is because of TOO LITTLE + CASTER.
If your unit drives GREAT, like an SUV, it is because you have a proper amout of + CASTER which I am guestimating to be about +5.0 degrees or more. (Note: The RH caster is always more then LH (CROSS CASTER = LH - RH))