jej3

Well, my 1990 S4 is running well but seems to find all the ruts in the road when driving. I would consider it to be a bit loose feeling; definitely wanders on the street (not so much on highway).

Car is approaching 160K miles and I am assuming that it may have gotten a new steering rack in its life but it's not new anymore

As a matter of fact, I figure all of the following are likely closer to original than new....

1. Suspension (dampers/shocks)
2. Bushings
3. Wheel Bearings
4. Steering Rack and Tie Rods
5. A Arms
6. Power Steering Lines

So, with SITM on the horizon, do I bite the bullet and put some new spring in the car's step and dampen everything that moves (i.e. bushings). I am thinking yes but need more advice....

If I do this, should I not replace the rack with a rebuild (leaks a little), and a PS update of lines (probably get rebuilt @ Pirtek) and reservoir?

If I drop the rack, do I also do the Motor Mounts and OPG?

Help me prioritize before I decide to due every project below the car that needs to be done and end up with more to do than time allows

Thanks!

Mrmerlin

first a few questions
how old are the shocks? time for a set of Bilstiens

where is the rack leaking? into the boots depending on how much its leaking into the boots it may be OK if its leaking from the sealing washers or lines thats a different leak

check the ride height,
what is it?
of course do this before lifting the car.

a quick check for steering issues,
running the engine,
lay on the floor look behind the rear edge of the front wheel,
while helper slowly turns the wheel back and forth a few inches,
what your looking for is play in the tie rods and the rack in the cross member

James Bailey

The steering rack bushings when they perish from oil leaks and time make the car feel VERY loose as it "self steers" tramlines..... it could be as simple as that !!

jej3

Thanks for the speedy reply.

I would say shocks are O-L-D

I honestly need to investigate if it is the rack or the lines that are leaking. I am not having to top up PS fluid from reservoir hardly at all.

Ride height is pretty dead on spec (at least in front)... I measured it a few weeks ago (was contemplating lowering front end) but it was approx 165 mm on the fronts. Didn't measure the rear.

Sorry to be ignorant but what constitutes "play" in the tie rods and cross member? Wobbling as wheels turn or ?

jej3

Thanks, Jim! Common sense is telling me I'm not going to go wrong if I DO replace springs/dampers and steering rack bushings.

Just wondering if I need to then contemplate alot of other WYAIT .... YIKES

James Bailey

The steering rack is held to the lower engine crossmember by four bolts which pass through 4 metal and rubber bushings. When worn and oil soaked the whole rack can and will shift from side to side even though your steering wheel stays straight both front wheels will turn together as the rack shifts when they catch an irregularity in the road.
Shocks have little to do with tramlining. Worn tie rods play will allow one wheel to turn and compromise the alignment but the self steering effect is much less than worn rack bushings since only one wheel is self steering.
New shocks will no doubt help the ride but do little for correcting steering looseness...

Alan

It could also be something very simple like unevenly worn tires, wrong size tires, wrong offset wheeels or just a bad alignment.

Check tire wear (esp inside edges) if unevenly worn you need at least a good alignment.

Lift the car and feel for play in the wheels - all planes (left/right, up/down, in/out).

Start with the simple/cheap stuff

Alan

jej3

There is simple/cheap stuff on the 928s?

Good advice. I noticed the problem before SITM last year but I like driving the car more than anything...

Tires on front are correct size and are wearing evenly.

Everyone is giving me good food for thought

Alan

Everything is relative...

Alan

gruffalo

Make sure the toe is correct.

Jack up the pass side wheel. Grab it at 3 and 9 o'clock. Wiggle it back and forth. Have a helper inspect where the movement is.

Most likely you will find the movement in the steering rack bushings or the end of the rack itself. If the latter, you may try to custom fit an extra bushing to the end of the rack, or ultimately overhaul the whole unit.

What tires do you run?

I've got two sets of wheels. One tramlines like crazy, the other does nothing, both are et65. Go figure... And I do indeed have a loose rack end.

Some 928s do this more than others, it can sometimes be hard to figure out.

I know Bill Ball has got some ideas on the subject, others too.

Good luck!

M

NoVector

Probly not the problem, but worth taking a look. If a PO put in a bad batch of poly bushings, this is what happens when poly goes bad. My 84 began drifing - looked at the bushings and holy cow! Replaced with a new set from 928 Intl and it was all better. Good luck.

jej3

Does the rack need to come completely off the car for the delrin bushing install? If so, shouldn't I at least tackle motor mounts and opg?

gruffalo

Nope! You can replace them without dropping the rack

Schocki

Changing to DELRIN does not take a lot of time and is really rewarding!

jej3

Last stupid question....

Sorry, Rennlist search isn't the best.

Is there a procedure for replacing the bushings while rack is NOT dropped?