<E30> ps rack replacement (longish)

[Evan Arnerich <arnerich@xxxxxxxxxxxxxxx>]

I recently replaced the steering rack in my '87 325 eta. I had
discovered that ps fuild was leaking into the steering rack boots (no
external leaks, but I could hear the fluid slosh around in the boots).
Wanting to keep the power assist, I opted to replace the leaking rack
with a rebuilt unit.

For your reading pleasure, I'll describe the steps:

1.  Clean the gunk off at the do-it-yourself carwash both from top and
bottom, taking care not to get any electricals soaked.

2.  Disconnect battery.

3.  Center the steering wheel, locking it in place by removing the key,
then safely raise the car on jackstands.

4.  Disconnect tie rod ends from strut housing. I had to remove calipers

then rotate the backing plates for enough clearance to get a gear puller

type tie rod removal tool on the nut, YMMV.

5.  Disconnect the steering shaft-to-rack u-joint assembly by loosening
both ends and pushing assembly up on steering shaft (coming through
firewall). The bottom part of the u-joint should then clear the rack.
Tighten upper bolt to hold u-joint assembly in place.

6.  Drain ps fluid, most easily done at the lower end of the hose from
the res to the pump, then replace the crimp-type clamp with a
screw-type.

7.  Disconnect hose fittings at rack (catching any fluid) and move hoses

out of the way.

8.  Unbolt the rack from subframe (bolts drop down).

9.  Bentley neglects to tell you that the oil pan and the subframe (at
least with my eta 6-cyl) are too close to allow the rack to just slide
out, so you must either:
    (a) lift engine 1-n inches (you're on your own here), or
    (b) carefully bend the lower subframe tabs down (1/4 - 1/2 inch at
the most) until the rack has enough room to clear the subframe and oil
pan, and is free to drop down. I had to turn it in multiple ways to
finally snake it out. BE VERY CAREFUL IF YOU DECIDE TO BEND THE TABS.

10. If you're also replacing the tie rods, remove the rubber boots from
the old rack, and adjust the new tire rods to the same length as the
old (each side may be different). This will get your wheel alignment in
the ball park. When I took the old boots off, several fluid ounces of ps

fluid was found, so be ready to catch this.

11. Assemble and torque everything just like the old rack, with new lock

plates, rubber boots, and clamps.

12. Center the steering rack (I counted turns lock-to-lock, then divided

by 2), and mark the shaft and housing to align in step 17 below.

13. Snake the new rack assembly back into place, and either (a) lower
the engine (see step 9a above), or (b) bend the tabs back up. I used my
floor jack and was _very_ careful here, YMMV.

14. Using new nuts, install the subframe-to-rack bolts and torque the
nuts per Bentley.

15. Connect the hydraulic lines using new copper (or aluminum) sealing
washers. Since the hollow bolts are different sizes, you can't mix them
up, however the BMW parts CD incorrectly shows 14mm washers on both the
14mm bolts and 16mm bolts. You'll need two 14x20mm washers and two
16x22mm washers, no matter what your parts supplier says. Steve D at the

Ultimate Garage is now aware of this, others may not be (like you local
dealer). I don't have a part number for the larger washer, but any good
parts guy should be able to match it if you bring in the old one.

16. Connect the tie rods to the struts, using new nuts (again per
Bentley) and torque to spec.

17. Loosen the top u-joint assembly bolt you tightened in step 5, then
slide the u-joint assembly all the way down on to the shaft on the rack,

making sure that the alignment marks you put on in step 12 are still
lined up.

18. To make sure your steering wheel and rack are lined up properly,
turn the wheel from lock to lock, and notice the position of the wheel
at full left and right lock. The steering wheel positions should mirror
each other. If they don't, disconnect the lower u-joint connection,
adjust, reconnect, test, repeat as necesssary. Don't rely on tie rod
adjustments to make up for a mis-alignment on this step. otherwise
you'll end up with a different number of turns to lock in each
direction.

19. Torque new locking nuts on both ends of the u-joint assembly.

20. Reassemble any brake backing plates, calipers, rotors, wheels, etc.
torquing per Bentley.

21. Fill steering reservoir to full mark.

22. Reconnect battery (reset radio code, etc.) and start engine.

23. Turn the wheel from lock to lock, adding fluid as needed, and check
for any leaks.

24. Turn off engine.

25. Lower car, recheck wheel bolt torque, eyeball alignment and adjust
tie rods if necessary.

26. Test drive, again check for leaks, and top off fluid if necessary.

27. Drive directly to the alignment shop.


As well as fixing the leak, my steering now feels a little "tighter"
with less on-center free play.

I got my parts from Steve D (no affiliation, etc.). I got a ZF rebuilt
unit and also replaced the tie rods. Parts cost was about $480. The
labor would run 3-4 hours at your friendly neighborhood BMW tech. I
didn't keep track of time because I started work before all the parts
were in, doing what I felt like each evening as parts arrived, until
complete. I haven't had the alignment done yet, since I'm setting it
by eye to some toe-out for an autocross this weekend.

If you try this, make sure you have all the parts you need on hand,
before you start. It will cut your downtime. Here's my list:

One new/rebuilt steering rack (duh)
Two steering boots
Four boot clamps (crimp type)
Two 14x20mm sealing washers
Two 16x22mm sealing washers
Two locking plates
Two tie rod assemblies (with new nuts)
Two subframe-to-rack self-locking nuts
Two u-joint self-locking nuts


Cheers,
Evan  '87 325

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