heres what i wanna know. ive noticed this, some hangers go way before others, for no aparent reason. on my 88, hangers are fine, no major cancer on them. i pulled at set of hangers off a 77 i think 250, and they were fine. i bought my 89, hangers are rusted through, and leaves are on the bed. my friend has a 85, and just this weekend he developed a crack in his driverside one. these are all local trucks, and they have no rhyme or reason to why they go out. why is this?

 

I have no idea.

When I restored my crewcab's frame, I found the same thing, though it was very odd to me. The hangers, brackets and the frame itself was much rustier towards the extreme ends of the frame, and the middle was almost damage free. Also, the passenger side has more serious rust than the driver side.

Why? I assumed the rust fairy just wanted to torture my mind.

 

Year to year changes in rust rates could very well coinside with changes in suppliers to Ford (be it raw steel, or finished hangers). Buyers are always looking for cheaper suppliers, or beating up current suppliers to cut prices. That job would suck, because mgmt is always after them to cut cost, and everybody else is mad because they keep trying to cut cost.

Frederic's issues with different areas of the frame being effected differently (front to rear & side to side) probably has a different culprit. OK, this may sound a little weird at first, it did for me, until I saw it displayed. The cooling fan on the engine will effect the airflow under the truck, and at highway speed, will result in more road spray on one side than the other. If you take a look at certain aircraft, this is displayed magnificently. The Beech T-6A is the trainer that the Military buys from Raytheon. It is a turbo-prop with dual exhaust, one on each side of the cowl. The soot from the exhaust coats the landing gear, leading edge and bottom of the wing on the right side of the airplane much heavier than the left side, because the prop wash throws everything to that side.

Most (later model) cars won't see that issue for a couple reasons. (A) They sit much closer to the ground, and have better aero-packages, so the airflow under the car is managed much better. And (B) with front wheel drive, tight engine compartments and electric fans, not as much air gets blown around under cars. Take a look at a car and a truck idling or driving slowly on a dirt road, most trucks (those with engine driven fans) willdisplay a cloud of dust near the right front tire, from the air coming off the fan, whereas a car won't show that tendency at all.

Kind of long and drawn out, but hope it helps.

Paul

89 F-150 SC 4x4, 300, T-18
KANSAS Chapter

 

I know this may be off topic but what you are talking about is called the "P Factor" which is prevalent in all propeller driven aircraft. Some of this also applies to helicopters with downwash. The desending blade pulls more air than the asending blade. Which in turn, when flying the aircraft you are required to apply oppisite rudder pedal to compensate for especially in climbs where there is greater torque. You notice this in water craft also as when you are moving you have to slightly countersteer and if you notice you have to apply more force when first taking off then when on the step and cruising. This is why they came up with hydraulic steering and counter-rotating propellers for twin engine set ups.