difficulty of this DIY in a scale level of 1-10 (10 being hardest) is a
Quit few numbers of 993 steering racks are starting to leak out here, the leak is generally very minor leaks around the rack seal area. It does not cause any steering malfunction unless the reservoir is drained of the fluids, which means if you are suffering a steering race leak you will need to check your power steering reservoir often. Since the leaking area is covered by a protective rubber boot the leak is generally not noticed until a much later time when the power steering fluid actually eats through the rubber boot and cause it to crack.
There are few places that offers remanufactured 993 steering rack for sale, you can easily find these places on line by doing a search for "993 steering rack" in yahoo search. After doing some telephone inquiry I found out that a remanufactured 993 steering rack costs around $450, and the core charge is anywhere from $150-$350. Just out of curiosity I checked with the local Autozone and found out that they also sell a remanufactured 993 steering rack for $455 ($150 for core charge), so I just decided to buy it directly from Autozone to take advantage of their life time warranty.
During the same time Hank was researching
a steering rack for his 993 RS project and found that the 993 RS steering
rack is a steering rack from a 964 unit part number 964 347 009 04.
I am not sure if this information would be helpful, but I have been told
that the 964 remanufactured steering racks are considerably cheaper than
the 993 units.
Steering rack removal procedures:
Remove driver's seat (This is optional, it will give you more room to work with under the pedal cluster area if you remove the seats)
Remove pedal cluster floor board. Go to this DIY for the floor board removal instructions.
Jack the front of the car up and placed on jack stands and remove the front wheels. Go to How to jack the car up for front jacking instructions.
From the center position of the steering
wheel turn the wheel until the steering shaft universal joint bolt is exposed
in a position where you can get a socket to loosen it. Once the bolt
is removed you will need to tap a chisel of a flat screw driver into the
split opening of the spline clamp and tap the universal joint upwards to
make sure that the spline clamp can move freely. (Example in right
hand side picture) But you do not want to remove the spline clamp from
the shaft at this time, because you will need to turn the steering wheel
in later procedures.
Unbolt the 10mm bolts from under the front
plastic pan and remove the pan
Unbolt the tie rod bolt on the left and
right side hub.
Use a tie rod remover to push the tie rod
out from under the hub on each side of the car.
Loosen the tie rod locking bolt (when loosen
the locking bolt you will need to use two wrench to prevent putting pressure
on the steering rack)
Loosen the tie rod from the ball joint
(count the exact number of turns it takes for the tie rod to comes off.)
My count was 18 on each side.
Slide the rubber boot off the ball joint
and loosen the ball joint (Also using two wrench at the same time)
Unbolt the hydraulic feed and return line
(17mm) on top of the steering rack unit from under the car. (Difficult
to get to) At this time you want to have some rags and a drain pan
ready because as soon as you loosen the bolt the power steering fluid will
come pouring out. Also have something ready to cap the lines
with. I used the cut off finger section of my latex glove tied with
a wire tie. (It's messy!) Be careful not to loose the brass
seal rings when you remove the hydraulic lines. There are two brass
rings on either side of the line connector on each line.
Remove the 4 allen steering rack mounting
Did not have a chance to take any pictures during these following procedures, so you will just have to use your imagination.
Have someone turn the steering wheel all the way to the right, and drop the steering rack on the right side down first. Once the right side have cleared, turn the steering wheel all the way to the left so that the left side of the steering rack will clear the cross member and drop down.
Once the old steering rack is out you will
need to swap over the mounting rubber/metal bracket and the hydraulic line
holder bracket and boot over to the new rack.
When I removed the rack I made a mistake
of taking off the complete steering column universal joint with the rack.
The reason why it was a mistake was because it was very difficult to reinstall
the universal back to the steering shaft correctly. But it did help
me in positioning the steering rack arm in proportion to the original position
prior to installation, so that I only had to do a very minor adjustment
of the steering wheel to center it back.
Reinstall the steering rack left side up first and line up the spline shaft with the spline clamp from the top side and then once the spline clamp is secured turn the steering wheel all the way to the right side to get the right side of the steering rack up.
Install the steering rack mounting bolts just hand tighten. Only one side of the steering rack bracket touches the cross member of the frame, so you will need to tighten those bolts first so that the mounting bracket almost touches the cross member, and then tighten the longer bolts on the opposite side until they bring the bracket up evenly. And then go back to tighten the bolts on the cross member side to 45 Nm, and then the long bolts facing the front of the car also to 45 Nm. (The factory shop manual recommends that the steering rack mounting bolts to be free of debri and oil when it is reinstalled, also now it would also be a good opportunity to perform the TSB on the steering rack bolts on earlier model 993s, it also states to replace the bolts once they have been removed.)
Install the feed and return hydraulic lines tighten to 20 Nm.
Under the left side of the steering rack
gear box you will find a hole that either have a black rubber plug on it
or has been filled with some sort of silicon on a remanufactured rack.
Remove the plug so you can observe the steering rack centering hole.
Now you need to turn the steering wheel so that you can see a dimple through
the pilot hole. Once the dimple is lined up with the pilot hole you
know for sure that the steering rack is at the absolute centered position.
There is a taper head bolt that is used to lock in the center position
of the steering rack, I didn't use it during this DIY because I didn't
have access to that special bolt.
Now is time to center the steering wheel.
Disconnect the negative terminal of your battery. Remove the two
torx T30 bolts behind the steering wheel on each side to remove the air
bag, (The factory shop manual recommends
that the air bag bolts to be replaced each time they are removed.) disconnect
the air bag and place it with the padded side facing up. Remove the
steering wheel bolt and and spring washer. The wiring connection
behind the air bag works like a spiral spring "Coiled contact unit", it
will allow only so much wind-up in each direction. So it may be damaged
if it is not reposition to relieve the tension from the incorrect position
of the steering wheel. The 993 steering wheel assembly have a device that
automatically locks the "coiled contact unit" when the steering wheel is
pulled back. To center the "coiled contact unit" properly
you will need to place the contact unit in the end stop position.
Starting from end stop position, turn back contact unit by two turns and
continue turning to the center position mark. The exact center position
is indicated by two arrows in the picture below #1. Once the "Coiled
contact unit" is centered you can now mount the steering back. After
centering the steering wheel, install steering wheel bolt tighten to 45
Nm, air bag, and air bag bolts (10 Nm), and then connected the negative
terminal of the battery.
Reinstall the ball joint tighten to 70Nm
and install rubber boot, replace any cracked boot. It will help with
the installation of the rubber boot if you use some grease on the lip of
the boot. You will need to slide on the rubber boot first and then
have someone else turn the steering wheel to either direction so you can
get enough access to slip the boot over the locking lip. (Very
frustrating process that took me over an hour!)
Install tie rod and count the numbers of the turns that you wrote down when you first removed it.
Tighten the tie rod locking bolt to 45 Nm.
Install the tie rod back into the hub and tighten the tie rod hub bolt tighten to 75 Nm.
Install the steering column universal shaft spline clamp bolt and tighten to 23 Nm (Factory shop manual said to use new bolt)
I then test the system for leaks prior to installing the front pan back on the car.
Here is the procedure to bleed the power
Reinstall the front pan, and then the front wheels. Lower the car and you car done!
(It is recommended
that you will still need to get the front toe-in checked on an alignment
machine just to be sure)