Toyota Steering Box
The Toyota power
steering setup is a nice system with one major drawback, the
steering box it uses is 20+ years old. You may get lucky and
have no leaks for a while, but it will happen sooner rather than
later, puddles on the garage floor and a constant drip of power
steering fluid running down the frame. Mine started the day
after it was installed. I noticed the driver side wheel well
was always shiny. Turns out there was a slow trickle of power
steering fluid coming from the box. Worse yet this stuff is
flammable. It has a high ignition point, but once it gets
there power steering fluid does burn. You can get a new pump,
new hoses, even new coolers, but a new steering box will run you a
cool grand from the Toyota dealer. What to do? I ignored the
problem until it started leaking a couple tablespoons a day while
sitting in the garage. That was the last straw. I took
my new impact wrench and started disassembling the steering box.
safety glasses. There is a lot of fluid in the box, if you
turn the shaft (and you will) it will squirt power steering out when
you least expect it.
2 P/N 64492 O-ring (2mm wide, 10mm
ID, 14mm OD)
1 P/N 64036 O-ring (1/16 wide, 2-3/8
ID, 2-1/2 OD)
1 P/N 64139 O-ring (3/32 wide, 2-3/16
ID, 2-3/8 OD)
1 P/N 7007 Oil Seal (front seal)
(1) 30mm ID X 38mm OD X
7mm Width (4mm also works) Oil Seal (Sector Shaft Seal)
Lots of rags
Step 1: Remove the
pitman arm from the sector shaft and the steering joint from the
front shaft, then remove the steering box from the vehicle. Also
measure how far down the sector shaft protrudes from the bottom of
the box and write it down. You'll want to do the next steps
over a bucket or lots of newspaper. There is a lot of power
steering fluid stored in the box and every time I thought it was
empty more spilled out. Keep those rags handy.
Step 2 : Remove the nut
and sealing washer from the top of the sector shaft, then remove the
4 bolts from the top (see above picture). Once the bolts are
out, use a screwdriver to turn the screw that the nut and sealing
washer came off of and remove the top. The o-ring on the top
should be replaced. Next, carefully pull the sector shaft up
and out the top. You can now replace the lower seal with the
(30 38 04 seal). Set these parts aside.
Step 3 : Take a chisel
or a screw driver and place it in one of the grooves on the front of
the box. Next take a hammer and tap it counter clockwise.
This is just like removing a wheel bearing nut. Carefully
remove the front cap and replace the seal with the Napa oil seal.
Reinstall the cap.
Step 4 : Remove the 4
bolts on the front of the steering box. Carefully separate the
two halves, whatever you do, do not twist the front piece. You
should see a large o-ring around the front piece you just removed
and a small o-ring embedded in the main body of the steering box.
Replace these (I also put a thin layer of hi-temp rtv around the
large o-ring.) and slide it back together. Next replace the
Step 5 : Once you have
the front bolts torqued down, turn the front shaft all the way in
one direction. Next turn it all the way the other direction
and count the number of turns. Next turn the shaft back half
the total number of turns. The ball screw assembly should be
centered, visually verify this by looking at the teeth through the
top hole (see above picture).
Step 6 : Insert the
sector shaft thru the top, carefully slide it down thru the bearings
and thru the new seal. Next take the top piece and reverse the
order of disassembly. Remember, to get it to seat, you'll need
to use the bolt on the top of the sector shaft. Once the top
is seated, make sure the sector shaft sticks out the bottom the same
amount it originally did.
Step 7 : Install the 4
bolts in the top piece. I didn't find a new sealing washer,
instead I placed of the small o-rings over the threads, then the
sealing washer, then thread the nut on.
That's it. If I
missed anything let me know, I didn't think about writing a how-to
until I was halfway done, otherwise I would have taken more
pictures. On Fred Swanson's suggestion I purchased an
industrial strength hydraulic fluid to try instead of power steering
fluid. The fluid is called Hytran Ultra,it can be found at
CASE dealers (lift trucks and heavy equp.). I paid $8 for a gallon
of it. The fluid is supposed to handle heat better. I
can honestly say my power steering system runs a lot cooler now, you
can touch the cooler without burning yourself. So if your are
feeling adventurous give it a try and let me know how it works for