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Re: Leaning Spits

To: Michael Hargreave Mawson <OC@46thFoot.com>
Subject: Re: Leaning Spits
From: Nolan Penney <npenney@erols.com>
Date: Sun, 15 Apr 2001 21:51:28 -0400
Those numbers sound like mounted and loaded numbers, which  really don't tell 
you
anything about the springs themselves.  The only way to measure coil springs
effectively is to remove them and measure their freelength, and then their
compression rates on a bench.  Go ahead and swap the shock units up front, but I
doubt it will do anything good or bad.

If the car has a twisted frame, just as you get cockeyed loading out back that 
you
can see, you get cockeyed loading up front, it just isn't as visible.  You can
detect this cockeyed loading up front by looking at the clearance between the 
wheels
and the fender lips, though that isn't terribly precise.  Another way to detect 
this
sort of twisting is to measure the lengths of the shocks with the car sitting 
on the
wheels, which is actually what you did.  You didn't actually measure the 
springs,
you measured shock extension.  A usefull number for determining that the two 
sides
don't match in their position, but it doesn't tell you anything about the coils
themselves.

So you've verified that there is a cross chassis twist of some sort, but we 
still
don't know the actuall cause of it.  You've got more investigation to do.

You can get a pretty good idea of frame twist by parking the car somewhere that
allows you to get back from it a ways and look along its length from either 
end, at
a distance.  Look for perfect parallelness.  If you don't see perfection in how
things match along the frame, you've got a twisted chassis.

Open the bonnet and examine the two front suspension sides.  Make sure 
everything is
parallel or at least reflective of each other.  If one tower is collapsed in
compared to the other, or something like that, this will probably be at least 
part
of the problem.  You're looking for accident damage pretty much.

Examine the front springs to ensure they are a matched set.  Take a spanner 
wrench
and select one that barely fits over the wire the spring on one side, and 
compare it
to the other.  With the bonnet up kneel on that ledge below the bonnet latch and
deflect that side of the car, repeat on the other.  If the springs measure up 
the
same, and the car deflects pretty closely to the same amount, the springs are a
pretty close match.

Unbolt the sway bar as another mentioned and check it like he (she?) described.

But don't go buying new front coils, I doubt you need them, and you haven't 
actually
checked them yet.

P.S.
While you're having fun with your car, jack up the rear end by the differential.
The rear wheels should be hanging exactly the same.  If they are not, you've got
something buggering up the rear.  Now go try to lift each wheel on the rear, the
reaction to your efforts should be idential.  Again, if they are not, you've got
something buggering up the rear.  This doesn't eliminate front end troubles, 
but it
does help you zero in on at least one aspect of the problem (there can be 
multiple
sources).

Michael Hargreave Mawson wrote:

> I measured my front springs today.   The dimensions from the top to the
> bottom of the dished locating whatsits are... <cue drumroll>...
>
> Left Hand:      221mm (8.7")
> Right Hand:     209mm (8.2")
>
> She sags a lot more than half-an-inch overall, but this can't be
> helping!   I presume I need to replace my front springs? :-(

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