Mike, Steve,
As with the first rule of medicine, the first rule of engineering is, or
should be, "Do no harm." In this context, you don't want to add any more
weight transfer to the front of the car during braking, which some setups,
including the DWTA, do big time. This is the nice feature of the bolt-on
traction bars; they should only really function during acceleration,
primarily limiting axle rotation and transferring some weight aft,
depending on the angle of the traction bar. If you clamped the spring too
tight, then you would essentially duplicate the problem of the weld-on
bars. Some friction may be good to keep the end of the bar from slamming
into the spring eye, but rely on the spring eye to really limit the
movement during acceleration, and with relatively little impediment during
deceleration. In fact, you may want to add grease or Teflon, or some other
type of friction stabilizing material between the clamps and the springs. I
would not expect this loose setup to cause any particular stress to the
springs either.
Bob
At 12:01 AM 3/1/99 -0500, MWood24020@aol.com wrote:
>In a message dated 2/28/99 4:51:26 PM Pacific Standard Time, laifman@flash.net
>writes:
>
><< Next question: Can you really tighten it enough to prevent
> sliding on the leaf spring? What keeps the clamp from
> sliding on the leaf spring on high torque applications?
> How does it return? Should it slide?
>
> If it's clamped hard enough, does it distort the leaf
> spring., causing premature failure (hard to get new
> springs).
> Does the continual flexing fatigue that leaf spring?
>
> Of course the weld-on type is unequal length with the spring
> arc, which causes it's own problems, but the front weld can
> be cured with a doubler.
>
> Your thoughts?
>
> Steve >>
>Steve-
>I'll give your questions my best shot, but as you probably know by my other
>posts to this list, I'm kind of a seat of the pants guy; i.e. no engineering
>expertise.
>Anyhow, the front clamps are just tight enough to keep them from rattling.
>Mine don't seem to move around at all, at least that I can see by inspecting
>them. I have never considered fatigue of the leaf, but I run two primary leafs
>(a crude way of stiffening the rear springs) and don't see that as a real
>possibility. I'm not sure how to account for the lack of fore/aft movement, it
>would seem that either the clamps are tight enough to prevent it or maybe with
>my stiffer spring set-up (with the back of the leaf pack unclamped, which I
>copied from the old Mopar "Super Stock" springs) the pinion angle doesn't
>change much. After 6 years of use, including lots of autocrosses and track
>work, I haven't encountered any problems.
>Now a question for you: Were the Jag/Salisbury posi's labeled "PowrLock"? Or
>was that a Spicer term? I was trying to remember when I responded to the
>original question. I do know that when I got my posi, it was NOS Rootes, still
>in the box. I just can't remember who made it or what it was called...I do
>know I got stabbed, paying $350 for the piece!
>Mike
Robert L. Palmer
Dept. of AMES, Univ. of Calif., San Diego
rpalmer@ames.ucsd.edu
rpalmer@cts.com
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