Dave Terrick wrote:
For all following the thread on "rear steering TR6's"... please read
on...
valuable "cents" to be dropped...
NO THE RWD CARD DO NOT EXHIBIT THIS BEHAVIOR AS A RULE. WHAT WOULD
RALPH
NADER HAVE SAID?!?!?!
I have raced many difference forms of vehicle, cars included a full
race
240Z, ITA RX7, my TR6, Tr4A, and many others. I will suggest that
the
problems lie not in the rear suspension but THE FRONT SUSPENSION
Think of it for a moment. Which end has steering control? Which
end is
more heavily loaded under decelleration or braking (or anytime)?
Which end
is most likely to wear out?
I suspect the problem is as follows...
1. forward momentum under decelleration tries to push the body
forward on
the chassis. Since the brakes are hooked on the "outboard end" of
the
frame via
i)wheel bearings
ii) trunnions with nylon seals infrequently inspected
iii) lower inner bushings made of some gooey rubber, long overdue
for
replacement
iv) all mounted to chassis brackets known for failure
v) all directionally located by tie rods which wear out
vi) Are sensitive to camber settings affected by rubber bushings on
the
upper control arm known for 10K lifespan at best.
vii) have ball joints which likely have not been inspected lately
and are
likely loose
All or any of the above weaknesses will cause the weaker side of the
suspension to change more than the other. This imbalance will cause
the
directional instability... the weaker side toes in more and pushes
the car
to the "good" side.
The rear suspension is less sensitive since there are only 4
bushings to
worry about (unless, of course the frame is of the rust colored
variety).
Deceleration REDUCES rear end load so logically, rear steer should
be more
of a problem on ACCELERATING...
Here, the chassis tries to stay in place against the torque of the
engine.
This would cause some toe IN, but not likely enough to worry
about. After
all, that' s what that round thing you hold on to is for... and, if
those
bushings wer so worn out as to cause problems, there would likely
also be a
great deal of negative camber alerting you to the problem already.
...so endeth the lesson.. hope this clears up a point or two.
Dave Terrick
Thanks for the lesson Dave. I will inspect my front end this weekend. I
suspect my tie rods. Since I have recently rebushed the front end and
changed the ball joints.
--
Roger Helman
71 TR6 CC67866L
Digimation Inc.
e. rogerh@digimation.com
v. 504.468.7898
f. 504.468.5494
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