Jaguar Power Steering

Hello,

I am looking to sort out my power steering on my Jag MK2 3.8, it came to me with a very crudely fitted rack & pinion power steering set up, this not only looks horrendously bodged but fouls & rubs etc, the rack from the research I’ve done is from an XJS, my dad has a Daimler series 2 and the rack looks identical apart form the tie rod rack ends, the rack brackets are home made and not square etc etc, I’m thinking get a jag xj6 series 2 subframe cut off the factory brackets and make good to fabricate to the mk2 existing subframe once all lined up and made good, making sure wheels aligned, I have read stories about cutting column, tie rod ends etc, anyone who has done this or knows the pitfalls any help, pictures etc would be greatly appreciated, regards Paul.

My 1965 3.8S has had a rack fitted for 20 years or so. The shop that did the work in the San Francisco Bay area acquired the bracket which fits well. I do not know their source. I acquired the rack from a supplier in San Diego and specifically asked for a ZF rack as from my years in Jaguar warranty I knew these late XJS racks were more reliable and less leak prone than the earlier ones which I think were Adwest. The steering column did have to be shortened slightly but the splines matched up to the rack OK. I run the standard generator mounted pump which powers the rack with no issues. New hoses had to be made up by a hydraulic shop to connect to the rack. The downside of an rack on a Mark II, S Type or 420 is that you loose the Ackermann effect that the old pitman arm and linkage provided, This results in some tire scrubbing on turns, more severe the tighter the turn. My research indicates there is no solution for this. Due to the loss of the Ackermann effect the turning circle is reduced and early tire wear on the inner edge of the tires is an issue if you drive the car a lot and more if on twisty roads, The up side is there are no leaks and the car steers with the precision of a modern vehicle with no play in the system. Moss Jaguar sells a complete kit to convert, hoses, mounting bracket, rack, tie rod ends, etc to do the complete job. Search Moss Jaguar, early sedans, steering for full details. Not sure what type of rack they include.

I have had M&C Wilkinson rack conversion since 2002. See:


It has been OK, with same downsides John described. The kit was not so complete in those days, I kept original dynamo & pump. Later I put Dynamator in, original pump still working.
Köpi

Hi John, thanks for the reply, it’s a shame you don’t know where the brackets came from, yes I think mine is the ZF rack, if the column is shortened how about the horn assembly in the column tube, my column was cut down to fit the rack & UJ and they fitted an aftermarket horn on a crude cheap plastic rocker switch under dash! Turning circle on mine, tyre scrubbing and bad handling were many of it’s issues as well as bump steer etc, do you happen to have any photos of the rack on the car to get an idea of how it’s positioned on the subframe and how it sits in general with regard to position near chassis legs and suspension setup, any pics would be greatly appreciated John, Regards Paul.

Many thanks for the reply Kopik, I have requested fitting instructions to see what’s entailed, there kit is a lot cheaper than others I have seen available, interesting to hear your kit has been fitted a long time and all ok, again is there any chance of any photos of your kit fitted on the car, to gauge an idea of how it looks position wise etc, it would be greatly appreciated, regards Paul.

If you call Mc Wilkinson they might sell you the brackets, I know a garage that did.

Thanks Phil, I’ll give them a go, regards Paul.

Sorry I do not know where the shop I used obtained their bracket but I may have come from XKs when they may have sold a bracket as a separate part from the complete kit. There was no issues with the horn since all the column modification took place forward of the firewall in the engine compartment. The horn (at least on my 3.8S) is fed by a wire that attaches to a contact through a oval hole in outer column casing just above the floor boards. The whole horn operation set up is a bit complex (I know, I have, over the years, had it apart a few times). You will have to study the WSM to understand how it all works.

I’ll attach a few pics of my rack mounting but some are really poor photos. I need to take better ones when the car is on a lift. It all works without anything fouling other components.

.Center of vehicle with Rack installed, small

Paul Shields, Further to my earlier comments here is a picture of the inner column and the horn components and wire in the column, As I said it is a bit complex and takes a while to get your head around how it all works. BTW, you have not identified where you are located in your header.

Paul Shields: And still more photos.

My latest Mk2 had the Wilkinson system installed when I bought it and initially I was quite impressed however a couple of points worth noting.
it is not a progressive system despite their claim. the electrically operated hydraulic pump would normally be connected to the vehicle ECU to receive the relevant signals. What I think they did from tracing the wiring is simply connect the alternator out to the pump thus giving some kind of signal as speed increases (capped at 14.5 volts) which gives a totally undetectable variance in steering assistance.
Secondly you do get uneven tyre wear as has been stated above.
Lastly and this is the reason I removed it all, try driving it quickly on a twisty road and I just didn’t feel I was in control, you get very limited feedback through the steering and the steering feels ‘dead’ which I don’t like.
one other consideration you must inform your insurance company of the mods and in theory given the extent of the modification you should have to obtain an MOT every year.
I reverted to a totally original manual non power steering using a higher geared mk 1 steering box and love it. its a pig to park as the steering is heavy but on the road I just love it. This is all very subjective and depends how you want your classic to behave and feel.
best regards
Phil D

Thanks for the info Phil, I was looking at the Wilkinson kit last night, we have decided going to try make what we have work but obviously a whole lot better, as the kits are so expensive and a shame to throw away what we have, if we can re-engineer whats already with the car, regarding tyre wear etc it seems all the kits have similar traits and it is just a case of compromise to get the best drivability possible, regards Paul.

Thanks John for all the pictures really close up and can see the lot, really gives a good indication of what’s required, we are going to speak to MC Wilkinson about brackets if no joy there my brother is going to make templates and fabricate them, your pictures are a real good indicator of what’s needed and how it should look, as for the horn like you say a real complex goings on, I initially had all my column apart to see whey wasn’t working then found out column had been chopped for steering rack as well as lots of parts missing of it, I now have a replacement column which will remain untouched any mods will be done after column on the u/j’s, Sorry I am based in the UK, regards Paul.