Rebuilding Steering Box


Rebuilding Steering Box

The hardest part of the rebuild was to get the gearbox out of the car. To remove the gearbox You have to do the following:

Wash the PS-gearbox area.

It makes your hands less dirty. Well, as they said, the fluid is a perfect hair conditioner. After washing, jack the car and remove the driver side wheel. Wash under the fender too as the gear mounting bolts are there.

Drain the PS pump

The draining was quite easy. Put a towel under the pump to soak all spilled fluid. No matter how careful you are, there is always some wild drops that seem to have a will of their own.

Disconnect the return line from the pump AND plug the pump end with wood stick, another hose or something. There will be no pressure in this connection.

Stick the return hose into a large enough bottle and tape it there. Leave a hole for air to come out as the fluid enters the bottle. There is at least as much fluid in the gear as there is in the pump reservoir. Loosen the reservoir cap to allow replace air come in.

Start the engine. The PS pump will blow the fluid out of the gear as it pumps air into it. However it will be drained more effectively if you SLOWLY turn the steering wheel. This requires that you have jacked the car.

Note that the gear does not drain completely but this procedure blows most of the fluid out of it.

Pull out the hose from the bottle and tap it. Disconnect the other hose and tap it and the PS-pump connector. Don't tighten the reservoir cap as this might form pressure inside the pump causing the tappings to leak.

Disconnect the steering wheel flexible connection

There is two ways (at least) to do this. I removed the two bolts since I assumed the it would be easier to restore the alignment at installation time.

Remove the BIG nut under the gearbox to disconnect pitman arm

There is a big nut under the gearbox. I didn't have a large enough tool to loosen this one but fortunately my friend had one. It was not so tight as I had assumed it to be. The pitman arm sits VERY tight and the easiest way to disconnect it is to use a puller that fits under the edges of the arm / shaft connection. The arm sits VERY tightly on the shaft. Do not use hammer because the pitman shaft is made of some soft material. It is easy to deform it. Once loose, you have done the most demanding part of the job.

The steering linkage is flexible enough to allow you to disconnect the pitman arm while the gearing is at place. Do it now because after you have loosened the three fitting bolts the whole gearbox will come down. If the arm would be in place at this moment, it would be a nasty job to quide the gear away from the motor compartment.

Remove the three bolts fitting the gearbox and remove the gear

The gear is fitted with three bolts under the fender. After removing these bolts the gearbox can be quided away under the car. I tried to lift it but there is not enough room that way. There are shims that MUST be put back to make the gear straight. Don't loose these. It seemed to be easiest to leave the top-bolt last to be removed.

Uninstall the gear

Fortunately mine fluid connectors came out easily. Good flare tools are a must. Here are some hints if the nuts refuse to loosen:

  • Spray them with CRC or some other rust solving agent, let them soak one hour. Shake the fluid tube to make the soaking more effective.
  • If the nut does not come out and if You have a replacement tube, cut the original and use normal tools to loosen it.

Turn the steering to other end to memorize the position of the steering shaft flexible joint. Failing to do this can cause a lot of job in vain.

There is a large cup at bottom end of the gear. It is held in place by a large spring that sits in a groove. There is a hole that can be used to remove this spring. Just push a screwdriver through that hole and the spring should be easy to remove. The cup comes out by turning the steering rod. At this point there comes a LOT of fluid after the cup. Also the hose ends tend to squirt fluid.

Remove the nut over the cover. This is a lock nut for over center preload adjustment. The manual says discard the nut. I didn't.

The cover can be removed by removing the four bolts. One of them does NOT have a washer. It should be that way. Remember the one that didn't have the washer. After removing the bolts the cover can be removed with the pitman shaft. Just push the shaft gently.

The Big piston comes out by turning the steering shaft gently counterclockwise. The worm balls come off at this point so be careful not to loose them. There is 16 of them and they come in 2 colours. 8 bright and 8 black balls. The order of the balls isn't important at this point.

Remove the steering shaft flexible joint and loosen the big ring that holds the steering shaft gaskets in place. The shop manual shows a picture with a hammer and screwdriver. I used plumbing tool to remove this one. Don't squeeze it while turning since squeezing locks it.

After braking the gear apart wash it, wash it and once more wash it.

Putting the gear together

The only tricky part of the installation of the gear are the worm balls. The shop manual describes how to use a special tool for this purpose but I found that there is an alternative method to do this.

Install the gear at a point where You have all the axial components in. Don't put the steering shaft sealings or the bottom cup. Move the rank piston to a point where you can see both ball holes through the cover opening. Move the steering assembly to a point where the worm screw just appears in the hole nearest to steering shaft. If the steering assembly tends to break apart (mine did), "glue" it with grease (not too much).

Insert 12 balls one by one turning the steering shaft clockwise. Put the balls in alternating black-bright-black. After inserting the 12th ball, you should see the first ball coming out of the other hole. If not, you didn't do it right. Use a little grease to "glue" the remaining 4 balls (check the order) in the ball return guide (which split into halves), and put it into place. Tighten the return guide screws and there you are.

Install the bottom closing cup. I used tiny amount of silicone to ensure this against leaks. Put the spring in it's place to hold the cup.

Install the steering shaft sealings. Ensure that the steering assembly is fully in. You should see an oil return hole. I used silicone to ensure tightness.

Install the pitman shaft sealings. Again I used tiny amount of silicone. Put the pitman shaft in place.

The pitman shaft cover sealing can cause truble because the seal itself is a ring but the groove where that seal belongs is merely square formed. I used (again) some silicone to fix the sealing in it's groove. Also the silicone compensated the small deformations on the cover.

I think that You can imagine the rest of the gear installation.

Oh, one more thing:

Adjusting the over-center preload

The over center adjustment is critical since if this is done wrong, the gear can crack.

The idea of this adjustment is simple. The tighter you turn the adjustment the more force is needed to turn the steering over the center line thus making the steering more stable at straight position. There should be a noticeable increase in turning force near the center. Don't make it too noticeable. Recheck the force after tightening the lock nut.

Putting the gear in car

The procedure is opposite to the removal. Bolt the gear in place checking that the steering wheel aligns properly. Remeber those shims, it's their turn before you tighten the fitting bolts.

Remember how hard it was to remove the pitman arm? You will be surprized how easily that piece of metal slips into place. Just check that the arm alignment is right before you tighten the big nut (remember the locking washer under it).

After doing all the plumbing work it is time to put the fluid into the gear.

As you noticed, there is more fluid in the gear than there is in the reservoir. I used the following procedure to fill in the fluid:

Start the engine. With engine running pour fluid SLOWLY into the reservoir. You hear a funny slurping noise as the gear soaks the fluid. There is a mark on the reservoir neck. Fill it up to that mark. SLOWLY turn the steering to the extreme left, and then to the extreme right. Refill fluid. Continue until the fluid level remains constant drops. In my case, the first lock to lock maneuver completely refilled the gear.

[ Thanks to Esko Ilola for this information ]