I'm getting ready to replace my manual steering rack with a fresher used unit than the original on my 83 944.

I've got new tie rod assemblies as well, and was looking for pointers on doing this.

Can I mount the tie rod assemblies on the rack and put everything back on the car as a unit, or do I need to do the rack first and then the tie rod assemblies? Are these threaded all the way on the rack end before applying pressure with the locking nut, or is their position on the threads related to the alignment?

Also, I'm replacing the middle steering shaft with the U-joints as well. If I undo the bolt for the top joint first, will it come loose by pulling back on the steering wheel, as someone suggested? I guess I should attempt this first to avoid stranding the car from not being able to get that shaft out.

How do I center the rack itself? I've heard of people using a "measuring tool" when installing a steering rack. Since the rack is longer on one end and the pinion assembly is in an offset position, I'm not sure what I need to measure. How does the bottom U-joint attach to the rack? There's a white marking that I assume must be lined up with something on the steering shaft.

Lastly, can I get a temporary alignment by counting the threads on the present tie rod ends and the steering knuckle, or is there some other way?

TIA

 

Um, I'll give a couple of these a go.

Yes you can install everything as an assembled unit.

I don't understand what you mean by the second question. I would remove the old rack and assemble the new rack as similarly as possible to what you removed from the car. Measure overall length with a measuring tape. Maybe even remove the tie rods from the old rack, making sure you count how many turns they were threaded onto the rack ends.

The rack gear has a dimple on the bottom side that a special tool with a ball end locks into to indicate the rack is centered. I made the special tool by grinding down the tip of a bolt. I don't remember the size, but I think it had a fine pitch thread (like that helps at all). Anyway, the bolt threads into a hole on the underside of the rack near the pinion gear. I'm not really sure you will need it though as long as you get the rack and tie rods assembled roughly the same as the existing rack and rods.

I have never heard of anybody pulling the steering wheel to disengage the steering shaft from the intermediate shaft. I can tell you that you should soak the splines at that connection with PB Blaster or something similar before you try to pull them apart. I pulled mine apart by dropping the rack and tapping the u-joint and tugging the rack. You may need to pry the female side of the connection open a bit with a fat screw driver through the split where it pinches together (sorry if that doesn't make sense, you understand when you look at it).

Yes, count the threads (or number of turns) on both the inner and outer ends of each tie rod.

 

Thanks for the advice. What I meant by "pulling back on the steering wheel" was that since I'm also replacing the steering shaft, I need to disengage the top U-joint and I've heard they're usually more stubborn than the bottom joint to loosen.

adie repeatedly indicated in a past thread that he does this by undoing the bolt on the top joint and getting in the car to give the steering wheel a strong jerk backwards. He said this helps disengage the U-joint and that he did this without loosening the rack bolts.

So how should the dimple on the steering rack gear be positioned for the rack to be centered? Should I align it with the (apparently) factory white marking?

 

Adie is a guy?

Anyway, look at the rack. On the onderside, near the bulge for the pinion gear there is a hole that may or may not have a plastic plug in it. You thread the special tool/ground down bolt into the hole once the plug is removed and the end of the tool/bolt will engage the dimple in the rack gear. If you get the position close you can simple tighten the tool into position until it just rubs the rack gear and wind the steering back and forth a little bit each way until you just feel the resistance of the tool release when it reaches the dimple (does that make sense). Or better yet, shine a light in the hole until you see the dimple and then thread the tool in to lock the rack into the centered position.

Make absolutely sure the round end of your home made rack centering tool (sorry I can't remember the bolt size) is super smooth if you use the "by feel" method I describe above. You don't want to scratch the smooth side of the rack gear.

 

Bolt for the tool was M10x1.25.

 

Thanks Michael.

Another question. What wrenches did you use on the tie rod assemblies? The lug at the end of the assembly seems to take a 33mm? However, the notches on it are too narrow to fit a conventional combination wrench -the Craftsmans are noticeably thicker.

The locking nut takes a 27mm and seems fairly straightforward to tighten against the lug.

 

Fortunately I used to help run a bicycle shop, so I have a bunch of thin open end wrenched. The wrenched I used are actually designed to be used on bicycle headsets and bottom brackets.

 

The centering bolt is often over looked on front alignments. Good call.

If the new replacement tie rods are the same as the worn ones they screw all the way into the rack and jam nut. Seen some parts listings where you have to use an adaptor and newer tie rods.

No mater how careful you are in measuring you should get the toe in redone if not camber and caster too.

As to the steering link; you only have to drop the rack. Don't mess with the steering column at all. Leave it attached. If you have to replace the steering link (it has u-joints) you can take it off of the end of the steering column after you remove the rack. Again don't mess with the steering column.

Also be aware of the brown grounding wire. This comes off of the steering rack and screws into the cross member. It's for the horn. In two recent occasions I've had to chisel the head of the screw off to remove this wire. Drilled and taped another hole into the cross member.

 

Oops, forgot about that ground wire. You need to reconnect it for the horn to work.

 

Socal and Manning, Thanks.

I'm replacing the tie rod assemblies because one is broken and has enough play to where the alignment is affected.

The parts I'm using are Porsche original equipment for the 944 manual steering rack. New old stock with the factory OE stickers (PN 944.347.033.01) that I picked up in an eBay auction. I was surprised to find that the PN stickers are the old kind with the Porsche crest on them.



I knew about the horn wire, but I need to replace the steering shaft because the U-joints have worn to the point where the horn doesn't sound unless I turn the steering wheel 1/4 left or right. Pretty dangerous for driving conditions here, where a working horn is essential.

As for the alignment, I found the dimple, thanks Michael! I was planning on taking the car in for that afterwards, but now that finding the proper wrenches is proving a major obstacle, I might have to give in and let them do the whole swap.

 

Luis,

Go to a good local bicycle shop and see if they sell tools. I know Park tools make a size that will fit, part number HCW-6. It is 32MM.

 

Michael, I found a suitable wrench, thanks. I also found 2 suitable M10 bolts and had one cut to 10mm to use as a plug, and the other machined to use as a tool like you mentioned.

It came out pretty nice. I'll post a pic later. To use it, do you just look for the dimple on the rack through the hole and tighten the tool into it until it holds the rack in a fixed position?

 

Visually locate the dimple, thread in the tool until you feel it touch the rack gear, then see if you can turn the wheels at all. If not then the tool has engage the dimple, if so then you need to move the gear just enough so the tool engages the dimple.

 

Thanks for all the helpful advice. You're becoming quite the authority on 944 manual steering.

Now if I can only interpret Zero10's write up well enough to rebuild my old one...

 

There isn't much to rebuild except for replacement of the bearings that support the pinion gear. I imagine it would be cheaper to buy a rebuilt rack than try to source and purchase the two gears. If you figure out the part number for comparable bearings though let us know what they are.