Coil spring question.

[gonzalo medina]

Will the original coil springs on my 72 f-100 fit in the 75 suspension I'll be using on the disk brake swap? The reason I ask is because they were replaced before I knew about the disk brake swap.

[FORDification]

The lower pigtail on the '73-up springs is larger, so the lower spring seat is different. The bumpside springs won't fit the dentside spring seats. You have to use the seats that match the springs, but if you also use the dentside radius arms, the bumpside seats will require some modification to sit flat...which is exactly what I had to do when I used bumpside springs with my front disc brake conversion:


On the left is the '79 spring, on the right is the '70, with the '79 spring pad sitting on top of each spring. You can see how the '70 spring will not fit onto the '79 pad.



You can see the modification to the '70 spring pad to allow it to sit flat on the '79 radius arm. This pic was taken while trial-fitting the pads. I dressed them a bit more, then they both got sandblasted and painted. I also had to install a large thick flat washer under the seat to allow it to sit flat, without cocking to the side.

[gonzalo medina]

So in order to use my bump springs that are brand new on the 75 dent equipment I must grind the end a little right. I have a bench grinder that I could use to notch the end. And the washer serves what purpose? I want to get my truck to a rolling chassis again?

[FORDification]

To eliminate the problem you could just use the forged bumpside radius arms, springs and seats.

The large washer was necessary when using the bumpside springs and seats on the dentside radius arms. The bumpside radius arms were a little longer on the front end and supported the spring seat just fine. The dentside radius arm, however, is just a little shorter on the forward end, and wouldn't support the forward-most section of the spring seat, so the washer was used to widen the 'contact patch'. Without it, the spring seat will 'hang off' the end of the radius arm and be tilted.

[gonzalo medina]

You said it buddy