I've done this and what do you know wrote an overview of the process. It's not a how-to as you need a manual really for all the interim steps I've skipped over.
Also interestingly the exchange rack I fitted might be an ST one as the steering lock is crap compared to the rack that came off.
Overview posted below (posted elsewhere but it IS mine!). If you need any help, give me a shout!...
Thought I'd put up a few words and pictures on my adventure in changing the steering rack on my old MK1 TDDI.
The reason I did this that I had a 'dead' spot on the steering just off of centre where resistance was felt when turning the steering wheel.
Anyway, I changed the lower arms and track rod ends a few weeks ago which needed doing anyway but did not cure it. I thought there may have been a tight balljoint etc.
Anyway the steering rack change.
This post should only be viewed as an overview of the process as if your attempting this type of job on your car you will no doubt have a workshop manual. Both me and the forum assume no responsibility if you use this guide and mess either your car or yourself up !
Special tools: Subframe alignment pins (bought mine for £16 off ebay). Balljoint splitter. Also you will need a 21mm socket, most sets only go up to 19mm. 15mm, 18mm spanners as well, most spanner sets don't have these and jump from 14mm to 17mm. a 7/32 AF spanner / socket to undo the hose clip bracket on the rack, again metric tool kits won't have this!
Time: Allow a day if doing this single handed, maybe less if your less fastidious about cleaning than I am, about half of my time was in cleaning.
Pic below; The venue, my garage, with the inspection pit I dug! In fact I built the garage as well!
Pic below showing the most important tool, a good workshop manual..
Pic below showing the car jacked up. There is lots of info on here about this. Best to jack from the cills and prop on the chassis rails that run about 300mm in from the cills. Note that due to the configuration of the inspection pit I could only do this on one side. I also like to go belt and braces when working under any car and you will see some old steel wheels with blocks of wood packed up to the chassis rails as well. This is a fail self as there are some very tight bolts that need to be undone and I didn't want to risk pulling the car off the axle stands.
Pic below shows the location of the subframe bolts. What cannot be seen are the upper subframe bolts. All of the subframe are very tight and you will need a good breaker bar to undo them..
Next two pics below cunningly shows the subframe alignments pins in place BEFORE I undid anything. I wanted to confirm all was well BEFORE I dropped the subframe to save grief later. If they didn't go in at this stage they wouldn't after!
Pic below showing the subframe pin kit, new ball bearing washers, a set of new 'o' ring seals for the hoses and possibly the pinch bolts for the column. What isn't shown is the new column plastic funnel / weather sheild / female urinal type type thing.
Pic below shows the column pinch bolt before being dismantled.
Pic below shows the column separated from the rack stub. Undo the 10mm bolt and then simply pull the sleeved section off the stub. There is no need to do any dash dismantling at all.
By this stage the car should be jacked up and safely supported with the wheels off and the column released from the rack. You will need to separate the anti-roll bar drop links from the antiroll bar. I chose to split the lower joint and leave the links on the car so they wouldn't get in the way. You will also need to undo and release the lower arm to hub balljoint. And quite obviously the track rod ends from the hubs!
At this stage as well it's a good idea to drain the fluid out of the system. I have a Pella oil extractor / suction pump so recovered as much oil as possible out of the reservoir, then removed the resrvoir and extracted as much oil as I could out of the hoses. I then undid the 10mm bolt holding the swash plate in place which turn holds the spiggots of the hoses into the rack. Once undone wiggle out the hose ends from the rack and prepare for spillage. I left an old washing up bowl under and went and had a cup of tea while it was draining. Pic below of the Pella, a really useful tool with a multitude of uses!
After my cup of tea, I released the the hoses that are clipped on to the rack via a plastic holder. You will need a 7/32 AF socket / spanner to undo the tiny bolt that holds this clip to the rack.
Then the fun part. Place your trolley jack in the centre of the subframe to support it. Then undo the the six subframe bolts which are very tight, a good breaker bar helps! Carefully partially lower the subframe with rack attached enough so you can remove the plastic funnel. The funnel pulls off the rack, this will expose the column stub. You can leave the column stub in place or remove it now. I didn't but but remove it at this stage if I were to this again as it makes it easier to remove the subframe from under the car.
Lower the subframe down, counter holding it as you go so it doesn't fall off the jack head. Once down, manhandle it off the jack.
Pic below shows the subframe lowered.
Pic below shows the subframe pulled out from under the car, be prepared for more spillage!
What I did at this stage was to move the whole lot onto my bench for cleaning, which took ages! I also decided to remove the lower arms from the subframe as it would make the thing more manageable when re-installing as I was doing this on my own. With an assistant this wouldn't be neccessary. My second reason for doing this was to fit a new pair of bearing washers to the lower arm mountings which I omitted when I changed the lower arms a few weeks earlier.
I also changed the antiroll bar inner bushes as well whilst it was all off. The anti roll bar needs to come off anyway to remove the rack from the subframe. The rack itself it simply held on by two bolts.
I spent a very long time cleaning everything up and fitting up the subframe.
One important thing is to set the design height on the antiroll bar at 98mm. Pic below gives you an idea but refer to your manual for more details.
During this mega cleaning session I also cleaned the fluid bottle which was rotten inside. I'd have bought a new one but forgot. It took a lot of carb cleaner, brake cleaner and careful use use of cotton buds on sticks to get clean!
Once the subframe is built up (Rack, ARB bushes, trackrod ends etc) its time to put back in the car. Which is a reversal of the removal HA HA ! (lots of manhandling but easier as there were no lower arms on it. Again if there were two of you it'd be a lot easier.
Pic below shows the subframe jacked up back in place with ALL the bolts in ready to be torqued up. Spot the mistake, I didn't fit the bloody funnel! I turned round to get the torque wrench and then noticed my error! I had to drop the subframe down again and fit it.
For those that are considering re-using the old funnel, the pic below shows the old a new side by side. I'd doubt the ability of the old one to suitably weatherproof again. The new one was about £14 from Ford.
That is just about it, re-filling the system is simply filling the bottle. I ran the engine with the car up in the air and went lock to lock to bleed the system.
The most important thing now was to get the tracking set so a trip to the tyre fitters is vital. I got a 4 wheel laser alignment done. The tracking on the way there was shockingly out depite me thinking I had it there or there abouts with transfering the measurements from the old rack to the new! The steering wheel was 90 degrees out LOL! After me and the tyre fitters having a good laugh about that, they did the business and the drive home was like being in a new car.
That about it for now. I'll post up some torque settings unless someone else could oblige.
Also any comments, or bits to add are more than welcome as you may have done this and may have a better way, a dodge or a workround that could be useful.