Re: Buggy Springs

[Tom Mandera <tsm1@domain.elided>]

Daniel Nees wrote:
> Actually, thinking about the dynamics here, with a normal front
> shackle/buggy spring, at full droop the driveshaft will pull apart more
> than it would with a reverse shackle and buggy in the rear. Just because
> of the direction of axle deflection. Therefore, I would think a front
> shackle driveshaft might be easier to make.

Dan - are you on medication for that knee?  That's two slip-ups this
morning!  Two conflicts - normal setup results in more "pull apart" than
a reversed shackle and rear buggy.  That's wrong.  "A front shackle
driveshaft might be easier" is *right*  

Stock setup (forward shackle) results in very little slip joint movement
- since as the spring compresses the axle moves forward.. closer to the
t'case (moves up) and farther (forward).  Droop, and the axle moves
down, but also towards the t'case as the shackle is flipped in-line with
the spring and the axle slides rearward some.

With a typical reverse shackle, as the spring compresses the axle moves
*rearward*.. so it gets closer to the t'case (up) and closer to the
t'case (moves rearward).  Droop, and the axle moves down and forwards..
away from the t'case in both directions.

With a buggy spring, forward shackle, the axle droops down and closer to
the transfer case.. since the buggy allows the forward part of the
spring to actually move rearward as it droops.

With a reversed shackle & buggy spring, the axle will droop down and
forward.. and then MORE forward as the buggy lets the entire leaf spring
"pivot" a bit and the axle moves even farther forward.