Metal Guru

After I increased the size of my front tires recently I encountered a problem with tire/wheelhouse rubbing when turning. A little research turned up an improved steering stop from Porsche to address the problem. The enhanced stop is thicker (10 mm vs. the O.E. 6 mm stop). Installing the stops involved the removal/re-installation of the tie rods.
The improved stop is on the right:

Metal Guru

Here is the procedure I used:
Tools required:
Open end wrenches 32mm, 22mm, 19mm, 15mm
Socket wrench and 12mm socket
Torque wrench
Ball joint press
Bentley manual (optional)
Brass mallet (tool of mayhem and destruction)
Scale

Metal Guru

Jack the front of the car and support it safely with garage stands.
Remove the front wheels.
Spray the tie rod jam nuts and ball joint nuts with PB Blaster or Kroil (my favorite).
Go make and drink some coffee while the penetrant soaks in.
Measure the tie rod length with the scale. I measured the distance between the two chamfers at either end of the rod. This will help you during installation so you can drive your car to the alignment shop when you are done.
Go back into the garage and remove the 12 mm lock nut from the tie rod end ball joint.

Metal Guru

Loosen the tie rod jam nuts (this will aid in freeing the ball joint from the steering arm and it's easy to do at this stage).
Put the ball joint press on the steering arm. Get the ball on the press rod into the recess on the bottom of the stud. When everything is seated and secure use the 19mm wrench to turn the rod and press the ball joint out of the steering arm.

Metal Guru

It's important to resist the temptation bang on the stud with a mallet; damage the stud end and it will be very difficult to remove it.
Ok, now lift the ball joint stud out of the steering arm toward the rear of the car, rotating the ball joint as you do so. Otherwise the coilover will interfere and prevent the removal.
Once the ball joint is free, take it off completely. This will make removing the tie rod from the rack rod easier.
Now go to the rack and pull the gaiter back. You will now see the steering stop.

Metal Guru

If you start on the left side of the car, turn the steering wheel to the right, full lock (I ended up tying the wheel to the door handle to hold it over). This will give you room to do this next step.
The steering stop is onto the tie rod end and tightened onto the rack rod. To break it loose counterhold the rod with the 19mm wrench and turn the steering stop counterclockwise with the 32mm wrench.

Metal Guru

Once the tie rod is loose, turn it counterclockwise until you can remove it. It's easier to remove with the ball joint off.
Now, install the new, improved steering stop. The Bentley manual says that a gap of 4 to 5mm must be set between the stop and the shoulder of the yoke. You can see it here. Depending on which side you are looking at, there will be between 1-2 threads showing at that gap. This is important to know as you will have to turn the stop to tighten tire rod to the rack rod and this will let you estimate the proper gap. You could make yourself a feeler gauge out of cardboard if you don't want to eyeball the gap.

Metal Guru

Now, thread the tie rod back into the rack rod. Set the gap and tighten the stop against the rack rod counter holding the rack rod with the 19mm wrench and turning the stop with the 32mm wrench (reverse of removal). Make sure when you have it tight (70 N-m) that the yoke is perfectly horizontal to the road.
Thread the ball joint back into the tie rod. Swivel the ball joint around and put it back into the steering arm. Thread the 12 mm lock nut back on. As you turn the nut the ball joint will rotate too so take a wrench and wedge it between the top of the ball joint and the bottom of the coilover. Torque to 65 N-m.

Metal Guru

Adjust the tire rod length to the value that you measured before you removed the tie rod (remember that the jam nut closest to the steering rack is a left hand thread). Tighten up the jam nuts. Now you are ready to tackle the other side.
When you are all done, reward yourself with your favorite adult beverage as you just saved yourself 2 hours of Porsche shop time ($100/hr here in Michigan). You can now re-set the toe yourself (strings and jackstands method) or take you car to a good alignment shop that works on Porsches and other exotics.

Marc Shaw

Great thread - thanks for the great instructions.

Copied to the 964 DIY forum.

Marc

ThomasC2

I hate ball joints, they stuck, threads break etc. When I do this operation a undo the toe-adjustment "pipe" instead and leave the ball joint in place. Just measure the distance between the inner fork and the tie rod first so you can put it back as it was. I find this method much quicker and easier.

LA964RS

excellent post and info.

Metal Guru

Thanks everyone.
Thomas, at some point you will have to replace your ball joints. What then?
I like a soaking in PB Blaster or Kroil, followed by the press tool. When you install the new ones coat them with a copper-based anti-seize.

ThomasC2

Yeah, that's true! What I meant is that I try not to split them if I really doesn't have to :-)

Your DIY-guide is really good, I just wanted to mention an "alternative route".

Gecko911

Metal Guru,

Thanks for the imformative post; images are very helpful.

I have the same issue running 235 tires on the front of my '89 C4; just a slight rubbing at full steering lock. I would like to install the "wider" steering stop. Do you remember the part #?

Thanks in advance,

Jeff

'89 964 C4 - White - Not Quite Stock....