Toyota Steering Box Rebuild

78-81 Celica

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. 

Caution:  Wear 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.

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 bolts.

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 you.