There are a few reasons why I
wanted to convert my stock Land Cruiser manual steering to Saginaw
power steering. The main reason is the stock manual steering
has 6 tie rod ends, tie rod, relay rod, center arm, drag link and
steering box. A little bit of wear in each of these
components can add up to a lot of 'slop' in the steering system
and leads to wandering, darting and involuntary lane changes.
A lot of the slop can be removed from the steering system by
replacing all of the tie rod ends and adjusting the play out of
the drag link and center arm, but you can only adjust them so
much.
I must say that I did not have any
difficulty with the stock steering system on normal wheeling trips
with minor rocky sections, but after running the Rubicon Trail
this summer, I was determined to have power steering. I was
physically exhausted at the end of each day just trying to turn
the wheels. The only mechanical problem I had with the stock
setup was when the driver's side tire was under compression and at
full steering lock to the left, the lugs on my 33" tires would
rub the drag link.
The 4 main components you need for
this swap include a 4 bolt / 4 turn Saginaw 800 series power
steering box from a late '60s GM passenger car, power steering
pump, pitman arm and steering shaft assembly. I got my
Saginaw box off of a '68 Chevy Impala, which has 4 mounting bolts
and 4.25 turns lock to lock. These boxes usually have the
casting number 5691676 stamped on the top of the box. The
steering box is mounted to the inside of the driver's side frame
rail just behind the bumper and is recessed into the front
crossmember.
Removal of
the Stock Steering Components:
I started this project by removing
the driver's side fender from the vehicle. This will give
you lots of room to work on this project. Disconnect all the
electrical connectors from the steering column. Unbolt the
steering column floorboard mounting flange and the dashboard
steering column retaining clamp. Loosen the rag joint clamp
from the steering box and remove the steering column form the
vehicle.
Remove the front bumper, drag link,
center arm, relay rod, and steering stabilizer. Remove the
steering box from its pedestal. The steering box pedestal is
riveted to the frame and is easy to remove if you have a torch.
If you are not that fortunate (I was not), grind off the tops of
the rivets and pound them out with a hammer and a punch. You
will also have to remove the front bumper brackets on the driver's
side so you can weld the steering box mounting plate (scab plate)
to the frame.
Steering Box
Mounting Plate (scab plate):
The Saginaw box is recessed into
the front crossmember and the output shaft is tilted up towards
the firewall to relieve the u-joint angles on the steering shaft.
The box is held onto the scab plate by 4 mounting bolts, which two
pass through the frame and two below the frame.
You will need to make or purchase a
scab plate (1/4" to 3/8" thick) which mounts the Saginaw box
to the inside of the driver's side frame rail. In order to
mount the Saginaw box level with the frame, the scab plate has one
1/4" spacer and three 3/4" spacers welded to it. I made
my own scab plate from a 1/4" thick steel plate and used a 1
3/8" hole saw to drill out my spacers from 1/4" and 3/4" bar
stock. Do not use washers for this!
Drilling the
Crossmember:
Bolt the box to the
scab plate making sure all the bolts are centered through the
spacers. Measure the distance from the center of the output
shaft to the back of the scab plate (the side without the
spacers). Using that measurement, scribe a mark that
distance from the edge of the inside frame rail to the center of
the crossmember. Drill a pilot hole at that mark and then
use a 3" hole saw to drill out the crossmember. This is so
you can recess the steering box (up to the return hose boss) into
the front crossmember.
Next you have to drill
another hole in the back of the crossmember to get clearance for
the steering shaft u-joint. The size of this hole depends on
what you are using for your steering shaft and related components.
Some people use a spud shaft that extends a few inches from the
Saginaw box input shaft through a smaller hole in the rear
crossmember. Instead of using a spud shaft, I used a
36" long Borgeson slip yoke steering shaft that mounts
directly to the input shaft of the steering box. Since I
already had a 3" hole saw I just cut another 3" hole in the
back of the crossmember to make extra clearance for the u-joint.
Remove all the bolts
except the lower bolt near the output shaft on the steering box.
Insert the tip of the steering box into the 3" hole and mount
the scab plate up to the inside of the frame rail using some
C-clamps. Exact mounting locations depend on what you are
using for a pitman arm, steering shafts, motor mounts and other
accessories in the engine compartment so do not do any welding at
this time.
Steering
Column and Shaft:
I used the stock
steering column for this conversion. Cut the rag joint off
the steering column shaft as close to the rag joint as possible.
I used a chop saw, but a hacksaw will work. I used 2 keyed
Spicer yokes (p/n 10-4-13) and u-joint (p/n 5-170X) to attach the
stock steering column shaft to the Borgeson slip yoke steering
shaft (p/n SL15N-836).
The Borgeson shaft and the Spicer yokes are for 3/4" round
stock.
The Land Cruiser
steering column shaft is slightly larger than 3/4" and the lower
few inches need to be sanded down to 3/4" so the pillow block
bearing (or Teflon bushing) and Spicer yoke can slide onto the
shaft. The u-joints are held onto the steering shafts by a
set screw. I machined 3/16" keyways into each of the
steering shafts and drilled and tapped the Spicer u-joint so I
could use a smaller set screw to hold the 3/16" key stock in
place.
Slide the pillow block
bearing over the steering column shaft and bolt it to the
floorboard mount. It is necessary to use a pillow
block bearing (which centers and supports the steering shaft at
the firewall) since the stock steering box has been removed.
A cheaper way to go is to use a Teflon bushing (instead of a
pillow block bearing) which slips over the shaft and squeezes into
the steering column. I chose the pillow block bearing since
it is has a grease fitting on the top. Reinstall the steering
column into the vehicle.
Mount the Borgeson
steering shaft to the Saginaw box and the Spicer yoke assembly to
the end of the steering column. The Borgeson shaft will have
to be shortened by a few inches (or more if you are using a spud
shaft). Before cutting the Borgeson shaft, make sure the
slip yoke is in the middle of its travel. Remember the
golden rule: measure twice, cut once. After cutting the
Borgeson shaft shorter, remount it to the Saginaw box and the
steering column shaft.
Turn the steering wheel
back and forth a few times to make sure there is no rubbing or
binding of the steering shaft assembly. If there is any kind
of interference or binding of the steering shaft assembly, loosen
the C-clamps and reposition the Saginaw box. It is normal
for the steering shaft to be 1/4" to 1/2" away from the motor
mount on a stock motor.
Welding the
Scab Plates:
When you are satisfied
with the position of the steering box, remove it from the scab
plate. Weld the scab plate to the frame. Drill two
1/2" holes through the frame for the upper mounting holes.
To prevent the frame from crushing when the steering box mounting
bolts are tightened, cut two lengths of 1/2" ID black gas pipe
and weld them inside the frame so the bolts can pass through them.
To help strengthen the
passenger's side front frame horn I boxed it in with another scab
plate. For this I used a 1/4" thick steel plate cut to
match the contours of the frame horn. I also cut a hole in
it so I would have access the tow hook and bumper mounting bolts.
Pitman Arm:
There are numerous
choices for pitman arms and your selection depends on how much
lift your Cruiser has and just how far the steering box is
recessed into the frame. I used a 2" drop pitman arm from
a Jeep YJ and it is about 5 3/4" long.
I found a few pitman
arms that would work great for different lifts. The Jeep YJ
(the one I used) had a 2" drop, the Cherokee had a 3" drop and
the Grand Cherokee had a 4" drop. All of the Jeep pitman
arms I saw had the indexing teeth off center by one tooth. I
used a triangle file and cut each indexing tooth in half to create
two teeth. This allowed me to center the pitman arm on the
box.
The 2" drop pitman
arm put my relay rod almost parallel with my tie rod to minimize
bump steer. I purchased a special 26" relay rod which had
a left hand metric thread to use the Land Cruiser tie rod end and
a right hand SAE thread to use a tie rod end to fit the pitman
arm. You can also cut the stock Land Cruiser relay rod to
26" and tap it for an 11/16" x 18 thread.
PS Pump:
Since my Cruiser's fan
belts are very wide compared to other vehicles, I wanted to find a
power steering pump pulley which would work with them. I
found a wide pulley which would work from a mid '80s Jeep or AMC 4
cylinder engine. I bought a remanufactured power steering
pump from the local auto parts store after the one I got with the
pulley leaked fluid.
I had a hard time
figuring out where to mount my pump on my engine. Most of
the conversions I have seen with stock motors, the pump was
mounted where the smog pump used to be. Unfortunately I have
to keep the smog pump where it is due to California smog
regulations.
The bracket I made for
the pump mounted to the driver's side of the engine using two
bolts form the water pump and two bolts from the head.
Unfortunately, I had to remove my York air compressor to fit the
pump on the engine. The belt is still tensioned by the smog
pump.
I bent a coat hanger to
mimic the bends I needed for my new power steering hoses and had
an industrial hose shop make new ones. The pressure fitting
on the pump I used requires a special metric o-ring seal, fitting
and crimp that most hose shops can not duplicate. I had the
shop splice the used pressure line I got with the pump to the used
pressure line I got with steering box.
I bought a little
automatic transmission cooler and mounted it to the front of my
radiator. I ran the return line from the steering box into
the cooler and then another line from the cooler to the pump.
This should help keep the steering fluid cool on those really
tough trails.
Results,
Impressions & Thoughts:
The hardest part or this conversion
was designing and making the power steering pump bracket. I
think it would have been easier to buy a power steering pump and
bracket assembly from someone rather than making one myself.
I even contemplated swapping in a V8 just so I would have a pump
and bracket already installed. I also would have had
an air compressor mounted instead of having to fabricate a new
mount for my York.
I am shocked at how nice it is to
have an 'over boosted" (as someone called it) steering system.
The Saginaw power steering conversion has made wheeling though
tough rocky sections easier on me and my rig. I can now
drive on the trails and the freeways without having to fight the
steering wheel. No more wandering, darting or involuntary
lane changes. My Cruiser has a totally new feel. I
consider this to be one of the best upgrades that one can do to a
Toyota Land Cruiser.
I want to thank Park Owens, Al
Kiecker, Jack Rice and the members of the TLCA's Land Cruiser
Mailing List (sponsored by Off-Road.Com) who helped answer all of
my questions during this conversion. They were a huge help
and it would have been more difficult and expensive if I did not
have their help. Thanks everyone.
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