REPORT: detailed 5k steering rack replacement

[Wallace White <wallace@remdesign.com>]

Last weekend I got around to replacing the steering rack on my 5kcstq.
It wasn't leaking badly, but it was leaking and the steering boot was
split, so I went ahead with the replacement. Here's my version of the
how-to, or rather how-I-did-but-maybe-not-the-best-way-how-to.

REFERENCES:
Samaras, Bill. "My rack replacement experience." Quattro list archives,
Dec. 9, 1993. (http://coimbra.ans.net/qlist/5000_steering_rack.txt)
Many other listers, notably Mike Arman who provided a good how-to.
(Thanks, Mike!)

PARTS NEEDED:
     1 	rebuilt steering rack
	(Jorgen Automotive, lifetime warranty, ~$175 plus $125 core)
     6 	sealing washers for rack and pump fittings (same size)
	(good to have extras around)
     x 	replacement hoses
	(some difficult to replace at other times)
     1  tie rod rock plate ("always replace")
     2 	liters of your favorite flavor of Pentosin
	(I would have more handy)

TOOLS NEEDED:
Just your standard Audi repair tools:
	Bentley service manual (mostly useful for exploded views and 
	 torque settings) (pages 48.2-5 mostly)
	good socket selection (though nothing larger than 22mm, I think)
	a few wrenches
	good torque wrench (44 lb-ft is the max needed, excluding lug nuts)
	chisel and/or Vise Grips (for the tie rod lock plate)
	a generous assistant
	cheap siphon pump (to empty pentosin reservoir)

TIME NEEDED:
Many people have said this is a four- or five-hour job. As a relatively
inexperienced mechanic, I needed more than twice that, which has been my
experience with other jobs as well. 

STEPS:

Center the steering (not crucial to alignment but for ease of removing
tie rod plate).

Remove the things that would otherwise be in the way of the rack: the
windshield washer bottle and the hydraulic reservoir. It is sufficient
to remove enough of the reservoir's hoses so that you can push it out of
the way.

Remove the two bolts holding the tie rods to the rack. You have to bend
the tabs of the lock plate out to get access to the bolt heads. I used a
variety of screwdrivers and a chisel with a big hammer. If you forgot to
get a new lock plate (like me) you should take care that you don't
destroy the one you've got. The nut and bolt running vertically through
the lock plate and tie rod bracket should be loosened but need not be
removed. Then you can remove the assembly from the rack. Tape the tie
rod ends to something, but keep in mind that you'll probably need to
move them around at stages during removal and installation. You don't
need to remove either tie rod.

Remove the flange tube, which connects the steering column to the rack
(see Bentley 48.2). You don't need to remove the dash trim to get to
this, though removing the little storage tray doesn't hurt.

Disconnect the hydraulic lines. I unbolted the pressure line but left
the short little return (which is really hard to get to) connected. Some
people recommend leaving both connected. Either way, pay attention to
their rough angular orientation and to which line goes where. They're
the same thread, but hooking the rack up backwards will destroy it.
(Other listers can vouch for that.)

Put the car up on jackstands (you don't need space under the car, you
just need to unload the wheels). Remove right-front wheel, where the
rack will come out.

Unbolt the rack from the car. It's held on the right side (passenger's
side on LHD cars) with a single vertical bolt and nut and with two bolts
on the left side. The rack is now free.

Go get your helper, if not already there. Begin the game of getting the
rack out through the tie rod hole in the fender well. We found that you
must:
	- pull the passenger's side end of the rack forward a little, 
	  then up high, and then pushing the big bunch of cables underneath it
	  (those are hard to clear)
	- wiggle the rack from both ends until you get the pass. end out the
	  tie rod hole.
	- rotate the rack (about its lengthwise axis) as needed to clear
	  hoses and such, till the rack is mostly out
	- rotate the rack till the column-end is pointing down, and then tilt
	  the whole rack till it will come out the fender

Before you even think about putting the new rack in, do the following to
the new rack:
	- Practice getting the flange tube onto the new rack. Note that it
	  is sort-of keyed; it only goes on at one angle. The fit will be
	  very tight at first, because of all the paint on the rebuilt rack.
	  Keep pounding the flange tube on (gently) until you can get it on
	  and off easily, because it won't be so easy once it's in the car.
	- Connect the tie rod bracket assembly to the new rack. The tough
	  part is getting the bracket connected to the boot. While one person
	  stretches the boot, the other can push the bracket into one hole at
	  a time. Again, I don't know how you would do this once the rack is
	  in the car. Then screw the two bolts into the rack, just to hold
	  everything in place for later.
	- Connect the return line to the new rack, at the proper angle and
	  with new crush washers. You _may_ want to connect the pressure line,
	  too, because it's tough to do later, but I found it too difficult
to 	  get the rack in with the pressure line connected. You really can
	  connect the line later, though with some difficulty.

Putting the new rack in is, of course, the reverse of removal, but it's
just plain tougher with the hoses and tie rod bracket attached. But it
really is worth it! We actually goofed and put it in without those
pieces, and then had to take it all the way back out. Don't do that. You
may find it necessary to turn the input shaft until you drive the tie
rod bracket to a convenient location for negotiating all the tight
spaces. It will tend to hang up on the wastegate. I even loosened one
tie rod bolt and tightened the other at times, to angle the lock plate
so that it would clear things. It _will_ fit.

Once it's in place, bolt it to the car first. Since you've got that
wheel off, it shouldn't be hard to remember to have the car up in the
air, but in case it isn't, the Bentley says "steering assembly must be
free of strain while tightening."

Now bolt the pressure line to the rack. This is tough, especially with
crush washers to fiddle with. But, it definitely can be done. We
actually put a little piece of tape to hold the washer onto the hose,
after dropping it so many times, and then removed the tape once the bolt
started in the threads. This made it much easier.

By removing one bolt at a time, _loosely_ bolt the tie rods to the tie
rod bracket and all. If you leave one bolt screwed in at all times, it
keeps the bracket lined up on the rack, so that it's easy to screw the
other bolt in. At this point you get your reward for having negotiated
the tie rod bracket past the wastegate and other obstructions. Do _not_
torque the bolts all the way yet: "tighten with vehicle standing on
wheels," Bentley says. 

Connect the flange tube to the rack and the steering column. Since the
shaft and the flange tube are keyed, you have to get the right
orientation--but you don't have to worry about the steering wheel ending
up at some funny angle. Just be sure to put the key in so that the
steering wheel can rotate. And don't put the bolt into the flange tube
until you've already got it on the shaft; it won't go on very far with
the bolt in. You'll need an assistant to push down on the steering wheel
while you connect the flange tube, so that the steering wheel is down
all but 1/8" of the way. Other listers have warned to be careful not to
break off the turn signal cancel tab; I don't know if it's easy to
break, but I'll mention that warning here. I didn't have any such
problems.

Lower the car to the ground. Reconnect the windshield washer bottle and
hydraulic reservoir.

Now torque the tie rod bolts up all the way. Bend the tabs of the lock
plate over the tie rod bolts.

That should finish the reassembly. All that's left is to pour fresh
Pentosin in and bleed the system, i.e. start the car and turning the
steering lock to lock, adding fluid as needed. I would agree that you
should do this with the front wheels off the ground, to be nice to your
new rack. Check for leaks. Enjoy.


That should about do it. There really isn't anything too complicated to
the job, though it takes a while to do (depending on your skill). Good
luck!

This report wouldn't be complete if I didn't give my thanks to my trusty
assistant on this job, my girlfriend Catherine Roller. She's actually
the cousin of a list member, Chris Silva, so maybe that's where she gets
her excellent Audi repair skills. I couldn't have done the job without
her.

- Wallace
  '87 5kcstq 150k