Re: Extended shackles

[Tom Mandera <tsm1@domain.elided>]

ScoutIIMan@domain.elided wrote:
> I was thinking (can be dangerous) that the diff wouldn't rotate from the
> extended shackles, only the frame would rise. I visualized that the distance
> from the ground to the bottom of the shackle would stay the same, no matter
> how long the shackle is. Since the diff wouldn't be rotating, but the frame
> would go up an inch or two, the driveshaft would angle up more, thus a
> greater pinion to driveshaft angle.

Close, Steve.

The diff "won't" move.. but you'll lift just the FRONT of the frame. 
Which means either the back end of the frame has to squat some more,
*OR*, far more likely, the frame will remain relatively level, and the
extra distance will be taken up by the front axle (and diff) "rocking"
slighly.  In this case, instead of lifting the frame, you're really
pushing the front of the springs down, which will make the pinion tip
upwards.

Like taking a "U" so it sits "level", then adding a little to one end..
you need to keep the tops of the "U" level (like your frame, give or
take), so the bottom of the "U" rocks a little, and instead of the sides
of the "U" being perpendicular to the ground, they are angled slightly
towards the longer side.

-Tom