The steering rack removed with the Metalastik mounts
The steering rack is mounted to the chassis using two quite large Metalastik mounts. The rather worrying part of this is that when the car arrived from the US the metal and the rubber of the nearside mounting had parted completely and that the other one was well on its way. You can see in the photo that the rubber/metal joint is starting to fail. The car wasn't steerable with one failed so..............
I considered buying an rebuilt rack but it's a pretty simple unit and relatively easy to dismantle. So I thought I'd have a go at it myself. As things turned out it was the last item that I was able to work on in my garage.
It was quite tricky to remove the tie rod ball housings from the rack as, in the absence of the special tool, I had to improvise a means of holding the housing. Once these are removed the rest is fairly straightforward and covered in the service (shop) manual.
The bushes in the rack tube and the housing were worn and had to be replaced. It took some time to get the ones in the rack tube out simply because it is so long. The bush is thin and it's difficult to get behind it with a long drift to drive it out.
I had hoped to re-use the old rack and pinion but the pinion was worn in one place. As can be seen in the picture one tooth has thinned considerably. I think that this must have been in straight ahead position where the rack and pinion chattered together as a result of the wear in the bushes.
I bought a new rack and pinion and a new bush kit which came with the bellows and all the lock tabs etc.
Once cleaned and painted everything was ready for reassembly. The new sintered bronze bushes are very thin and it is important not to damage them when inserting them into the ends of the rack tube or the housing. I made up a mandrel the same diameter as the OD of the bushes and after soaking them in oil used this to press them into the tube.
As this point in time (April 2004) events overtook me and I had to stop work on this project and ultimately lost the use of the garage. This meant packing all the smaller parts of the whole car into boxes and then figuring out what to do with a vehicle just about a dismantled as it possibly be. A bare chassis, a freshly painted body on a trolley with all the closing panels removed, engine, gearbox, rear axle etc. are all a huge embarrassment if you suddenly have to move them.
Click here if you want to know what happened next.
It is now 2012 and although a crude assembly of the car was done by Broomstick Cars in 2006 to make it mobile, I have now re-started work and am having to re-do, properly, much of what they did.
The upper steering column in its unrestored condition had been fitted without any attempt to clean it up. Also, the cap that retains the spring at the bottom and the spring itself had been left off.
To remove the upper column is a relatively quick job once the taper pin that locks it to the lower column universal joint has been removed. This took quite a lot of effort. Eventually it came and out not too badly damaged. I was able to clean up the threads with a die so I intend to re-use it.
The end was a very tight fit in the UJ but I persuaded it out by tapping on the brackets with a mallet.
It is impossible to withdraw the inner from the outer tube with the brass slip ring in place so the top bearing has to be removed. This bearing has a lip so it is possible to prise it out of the outer tube and once done the inner tube can be withdrawn with the bearing still on the shaft. I had removed the contact that connects to the slip ring through the hole in the outer tube about ten years ago but luckily it was still bagged up in my collection of parts.
It was evident that the slip ring was very worn so I took a large soldering iron to it and once the solder was cleaned off removed it. As expected the insulator under the slip ring disintegrated. The picture shows the remains of the insulator with the wire that goes up the centre of the column to the horn push. Also in the picture are the upper and lower bearings. The only difference between these two appears to be the lip on the top one.
These bearings come apart. The two halves are held together with an 'O' ring but this is just so that the balls don't fall out. It was my intention to clean them up and replace the balls but once they were clean and I could inspect the tracks carefully I could see that they were not worth saving as the tracks were full of little indentations.
I try to be mean and not spend more than I have to but I didn't want to put the whole column back together only to find that I didn't like the feel of the steering so I opted to replace them with new ones.
The bearings are available from the usual Jaguar suppliers but I couldn't find them in any of the bearing warehouses which means that they cost a lot more than expected. Often if you can find the source of the parts you can save some money but in this case Coventry Auto Components were the cheapest at the time but I still had to pay over £100 for a pair. This really upset me for two very simple bearings. nevertheless, it had to be done.
The way the horn connection works is that the wire from the horn push runs down the centre of the column, then turns through 90 deg. and terminates in a little brass stud. This stud is held against the inside of the brass slip ring by a spring. The stud and the spring live in a moulded tube which is part of the insulator that insulates the slip ring from the column. Fixed to the outer tube in the lower bracket is an assembly that holds the slip ring contact, also insulated, which rides on the ring as and thus the horn connection is made regardless of the position of the steering wheel.
SNG Barratt sell a kit of parts to repair the horn connections although this kit does not not contain the insulators that go in the bracket. Also, the spring contact appears to made from copper and is thus quite soft and not very springy. Beryllium copper or phosphor bronze would have been a better choice and so I shall re-use the original contact which, in comparison is much springier and will maintain a much better contact.
Also, in my kit the spring is too long and had to be shortened and there seemed to be many more parts than I needed. Maybe this kit does other models but I have no idea where the second copper contact, the long brass plunger with a grove which I suppose is for the circlip or the reddish insulator go.
Assembling the upper column is not particularly difficult. The new bearings are not a tight fit on the inner column so I degreased the surfaces so some bearing fit compound could be used to hold them to the column. First the top bearing has to be fitted to the inner and then the wire for the horn has to be fed into the column. At first I tried pushing it through through the exit hole and trying to persuade it t go up the inside of the inner. This didn't work as the wire just bunched up. Then I tried starting at the top and pushing the wire down. This didn't work either because the wire met an obstruction part way down. I then hit upon the idea of pushing the wire down a short length of 15mm copper pipe which I then fed into the top of the inner. Once I could see the copper tube through the exit hole I just pulled it back out a little bit, hooked the wire through the hole then held the end while I pulled the copper tube out and that did the trick.
The new plastic insulator needed a bit of fettling as the contact was very tight in its tube. It's important that the spring can easily push the contact onto the inside of the slip-ring. When I was satisfied that the contact was a good fid in its sleeve I threaded the wire through the insulator tube then through the shortened spring onto the wire and finally soldered the contact on to the end of the wire. Pulling gently on the other end of the wire I was able pull the spring and contact assembly into the insulator tube which I then fitted over the inner column. At this point I realised the the insulator was not a a tight fit on the inner and so I took it off again and wrapped a couple of turns of camera tape around the inner column in a similar way that I found it originally. This made it a snug fit and I was then able to push the slip ring over the the top of the insulator. The insulator has a groove cut in it and the slip ring has 'teeth' formed in one end the grip in the groove to top it sliding off the insulator in use.
Before going any further I checked to make sure I had continuity between the slip-ring and the end of the wire and that nothing was shoring to the inner column itself. All was well so I offered up the inner to the outer tube and refitted the upper and lower bearing into the tube. These are a tight fit and had to be tapped into place with some care.
The contact supplied with the kit is made of pure copper and is simply not springy enough. It is also too thin in comparison to the original part and I have serious doubts about its ability to maintain contact reliably with the slip ring. Fortunately I had the original contact and the two insulating mounting blocks. They are made of hard rubber and although mine were in good condition these are essential and in my opinion, should be included with the kit.
A final check to make sure that the complete assembly was electrically sound and the upper column is ready to be refitted to the car.
Jaguar XK 140 Restoration