triumphs
[Top] [All Lists]

RE: Do it yourself alignment question (TR3A)

To: <triumphs@autox.team.net>
Subject: RE: Do it yourself alignment question (TR3A)
From: "Randall Young" <Ryoung@navcomtech.com>
Date: Mon, 24 May 2004 21:54:53 -0700
> On a TR3 it may not matter, but (for what it's worth) it can make a
> minor difference on a Spitfire or GT6.  As the steering lock is
> increased, the steering geometry becomes non-linear, which is to say
> that the amount of steering angle dialed into the road wheel per
> input of the steering wheel isn't constant thoughout the turning
> range.

It's called Ackerman steering, and the TR3 has it as well, so it does make a
difference.  But as I said before, it's not a large difference when the
steering is nearly centered, so just visually centering before doing the toe
adjustment, then correcting centering as desired after a road test, is fine.
If you want to be really anal, recheck the toe after doing the centering ...
but it will be OK (within the repeatability of the car anyway, which
generally isn't all that good unless you've just gotten through replacing
everything).

> Suppose
> you were to rotate the steering wheel one notch in its splines at the
> top of the steering column, and compensate by adjusting both tie rod
> ends to re-center the steering wheel.

At least for the TR3, the book gives a reference for where the steering box
is centered, and the steering wheel should match.  But that's a different
topic, and not normally considered part of a front wheel alignment.

Being assembled correctly is an unspoken pre-requirement to any adjustment.

The steering only approximates the Ackerman angles ... and there's one
school of design that says it shouldn't even attempt it, because at the
limits of adhesion (which is where it matters the most) the tires will have
different slip angles anyway.  As I recall, Triumph Herald & derivatives
implement "anti-Ackerman" steering ... don't know about the Spit & GT6.

Randall





<Prev in Thread] Current Thread [Next in Thread>