.
Everbody
who have had a
bomber Chevy ( -49 - 54 ), knows about the center steering pivot arm
who easily get
some slack,, specially when front suspension etc. is modified.
After
some years strugling with this , I´d decided to do a major swap
of steering parts.
The
decicion was to fit a modern steering rack, with the most suited from
the German
Opel
Vectra / Calibra. Point of using this is that the hole middle section
is the movable part
(
with steering rods connections ) who would be pretty easy fitted
in use of orginal steering rods...behind the front framesupport,
and a use of Chevy Van
steering column. Both resonable priced at junkyards here. In
this chapter I´d try to show how this swap is done.
If you
dont
have a lot of time, garageintrest and creative sulotions thinkin´
, DONT DO THIS! exactly
measurements are of need!
The swap
uses lot of time for check,recheck and measurement before mount, and
this is crucial
for good
behavior on the road.And Rackmounting is´nt half the work. What
about get the right fanbelt wheel on the servopump, or rework another.
Get oilhose,tube and relocate it?
For shure, if used not powersteered type, half time was used. . .
.
RIGHTCLICK
ON PICTURE AND CHOOSE VIEW, TO SEE LAGRER SIZED PICs
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Here is an
overwiew of the
rack, fastners at side ends, steering column connection, AND
the middle section ( between the grummets ) who moves in sideways
direction as
steeringwheel is turned. At the middle section is also the orginal
connector for the tie
rods. Possible this needs a rework, or another bracket fabricated.  The
minimum widht of the racks fastners is approx. 8cm longer than between
frame, so some brackets under framerails should fit for secure
fastning. The right mountingclamp is adjustable sideways.
The orginal
opel steering rods have a total of 11.4cm shorter wideness
to use theese ones
directly at
wheelconnections., testing will show
possibility for to adjust this or new ones must
be made, or
that
orginal Chevy rods could be a easier fit.Because the forward middle
angle of Chevy tierods, a midsection connector must be
fabricated, and then the reversed Rs <> Ls Opel steeringrods is
used.Thats because of the rackjoints ( see Tie Rods )
*Tube outlettube near
the columnjoin nearly interfearence with the frame. |
CHEVY VAN TILTCOLUMN is in use, after orginal
steering
column/ box is removed.
The hole in
firewall needed a small adjustment to get axle and
gearshifter trough.
The upper
support at dashboard doesnt fit the larger tubesize, and
needs a new one.
This
column have tilt, and is easy to get cheap on aftermarket or
junkyards.
 
Left pic
shows the reworked lower columnmounting who got a bigger
square plate,
and to
right the
hole column, with all secure mounted complete. The bolts also holds the
pedalmount to firewall mounting.
Because of
beaty, the upper mount get a bracket plating to hide
mout to dashboard.
And
oldstyle wooden steerinwhell is modified to fit the column. |
 RACKMOUNTs is
fabricated.. For easyness of mounting, this has
got bolts welded secure in mounts.
If not the frame must get holes for the bolts exaggering inside.
The mounts is bolted with 4 bolts each, trough the frame sideflanges.
Mounting is measured for excact location, this is necessary for
straightness without binding.
On the Chevy the rack is mounted under frame, and needed adjustment on
angle to get goog connection to steeringcolumn. This angle shouldnt be
over 35 degrees re: experts.
At Chevy Van this reaches 40 - 45 degrees, and with the Van connect, it
seems no problem.
To get clearence for
the highpressure
hose connection, the
framerailflange
was cutted of 2cm x 5cm.
The rack is
finished bolted in the mountings. Middle tierod
connector
is seen in lower picturepart
Speed Direct - Delivers
a Stereoid TM Rack conversion for ex. the Corvette, who is similar to
the Opel rack used
here.
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ABOUT MOUNTING so far:
the rack needs rotational adjustment 
clockwise
from orginal Opel
mounting to get the steeringcolumn
mount the nearest possible,
without interference.Sideway adjustment to get the clearence of
framerail for
pressurehose, and handbrake
connection with ragjoint.
A notch in frame is the possible sulotion.
Cupling from the Chevy Van steering shaft to the Opel rack ragjoint
difference with 1mm,.
 To
use the orginal Chevy Van steerlinkage,
a rod with double D
.and other end D
needs fabricating. One end in 19mmØ , and other18mmØ., 70
mm long, to get this connected
to the Opel ragjoint.
Finished orginal linkage have 3cm slidetravel
in/ out All fastens with setscrews as orginal.
 Orginal
gearshift connection rod is mounted with orginal mount on the
Van column.
Powersteerings need a pump..............and this needs a place on the
engine.....when no mount is in garage, then fix one myself! Also took a
day to finish ,for pump
and adjustable generator
Mount. |
 OIL
,PowerSteeringtubes
- theese go around spooking the chassie?
Theese tubes has the lenght to lower the oiltemperature, and
because of pressure the tube dont like to be bent otherwise than
orginal, breakdown is possible with much altered curbs.
The tubes needed major rework and is now located reaching from
reservoar to pump,from pump, forward on
inside framerail lefttside.cross in front of radiator and back again to
the rack.
And thats the high pressure hose/ tubing. Return hose is easy, from
rack to reservoar |
TIE
RODs - 
Theese
are the
Opel orginals., they have roundeye connections in midsections,
and is made to connect to the rack.
TIE ROD
Connection- Outer end connect
as
orginal Chevy, same size on steering
arms,
bracket for the tierods inner connect needs
manufactoring, must be angled to get
tierods straight . To avoid using this, need of cutting from underside
of the frame to get the rack high enough, and rack must be mounted at
orginal forw / rearward rotated angle.
Instead Im using a bracket
between tierods and rackconnection, ( tierods MUST
have the same angle as lower wheelsupport to avoid bumpsteer, when car
stands on ground)
(rightclick and choose
wiew
image to get bigger pictures)
 
The
major
items to measure or verify to do a rack conversion will be:
1. Do you have clearance in a straight line across side to side between
the two tie rod centers and under the engine? If not the rack
will not work. Remember you can space the rack DOWN to get it
level, but you can't angle the ends but very little.
2. What is the exact length between the two tie rod ends now?
3. You'll need to make sure the steering linkage connection can be
accessed on the rack, so measuring from the left (driver's) side tie
rod end, between what points can this linkage come up toward the column?
If
you want to go
power, there are two
choices - box or rack. The box works fine if you have the space
to put it and can find one that will function in conjunction with what
you have. Of the problems that come up are incompatability
between the pitman arm and either the box or linkage.
Also,
you have to consider the column linkage because of the
combination column /box I believe is used on your car. Modify or
replace the column and linkage...
The rack has its own problems. First, you need to have one
the
right width tie rod end center to center and have the distance between
the main body of the rack and the tie rod roughly the same as the
length of the A-arm from pivot to ball joint to prevent bump steer.
Fortuneatly, Chris Alston makes racks in I believe 1-inch
increments so this can be solved if you can't find a suitable donor
with the right dimensions.
Second, you have to get linkage between the column and the
rack.
I believe your Chevy has an integral box/column shaft and so you
will have to modify this or go with a late column and linkage.
Third, you have to align the rack between the two tie rod
mount points
on the spindles in a reasonably straight line. This could be a
problem with clearances - either with the pan or with frame members.
1. Use the power assist
ram setup with
directional valve from a Granada. The ram attaches to the frame on one
end, the cross-shaft or tie rod on the other, and the spool valve is
placed near the Pitman. It's a bit of fabrication, but it might be a
way to go and keep the OEM front.
2.
Use a rack out of a Cavalier or Beretta or something like it that
has the center pivot - similar to what the Chevy already has but delete
the bell crank in the middle as well as the OEM box and attach the tie
rods directly to the rack.
1951
Chevrolet suspension works quite well and was actually used in the
Corvette thru 1962
the
A-arms must be the exact length of the
steering actuator arms to prevent "bump steer." Bump steer varies
the front wheel toe alignment as your wheels go up and down. So
if the A-Arms and steering actuator arms are not matched lengths you'll
almost always be out of alignment, affecting your traction and
impacting your handling.
Steering
Rack Spech:
New
ASTRA 1455kg. A Mondeo 2.0
weighs
almost
100kg less,
GM
Saturn L 2000
, has the Epsilon platform like the Opel Vectra
Newest
Malibu (2004) is built
on the same chassis ,General Motors' Epsilon global architecture,as the
Saab 9-3 and the Opel Vectra &
Calibra.
Same
rack on Saturn Aura, Opel Mervia, Opel Cavalier, Saab 9-3 &
9-5, with 3.0 V6
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