identify picture

[johngosnell]

I stuck the camera down the front of thed car , and I was wondering if what I am looking at, is the top of the steering box and can anybody ID which box it Is it . If any body is wondering why I cant climb under the car to look, it's not possible being in a wheelchair

Regards John
1B1257BW

DSC00304.JPG (6.28 MiB) Viewed 1801 times

[cass3958]

John this is the top of the Adwest Marles variomatic power steering box.
We covered it here http://jagstyperegister.com/forum_new/v ... =pas#p5528 with some photos of the system without the engine in the way. (Added again below.) The visual difference between this and the older Burman system is the Adwest had an aluminium top with four bolts where as the older Burman had a cast iron top with six bolts and the hydraulic system pipe popped out the top as well.

Adwest Marles Varamatic.jpg (105.33 KiB) Viewed 1794 times

Burman box.jpg (146.34 KiB) Viewed 1793 times

[Glyn Ruck]

There were 2 different Burman PAS Boxes fitted to the S Type. Three boxes in all including the the Varamatic.

Rob shows the so called Burman Type 2 above with the torsion bar "quill valve" on the input shaft.

This is the Burman Type 1 fitted to early cars.

pas_box Type 1.jpg (31.95 KiB) Viewed 1791 times

[johngosnell]

Thank you both for the info, I believe that the power steering was added at a later date purely because the car ID is 1B1257BW , if it had PS from the factory it would have had The Letter P in the ID. And also because the car is a very early 1964 car it would have had the first type of power steering not as confirmed the very late Veriomatic box that you have identified, this I thank you for.


Regards John

1B1257BW

[cass3958]

John you are right your chassis number should start with a "P" to indicate it was a factory fitted PAS system.

To retrofit the PAS steering box to the MK2 or S Type there has to be an indent in the front subframe cross member for the box to sit in as the PAS steering box is that much bigger than the standard non PAS box. When you do the conversion to PAS it is quite easy as long as you have all the parts and one of those is to change the front subframe over to the later one with the indent. I have seen some where the original cross member has been cut and then rewelded to create the indent for the PAS box to sit in but then you have to trust the welding skills of the fitter to get it right.

I think I am right in saying the later Adwest Marles PAS did not come in until 1966/67 on the S Type when it was fitted to the Jaguar 420 and 420G.

Taken from Wiki on the Jaguar 420

A novel mechanical feature that the 420/Sovereign shared with the 420G was Marles Varamatic power steering,[4] which was offered as an option on the 420 but was standard on the Sovereign. Built by Adwest Engineering Co Ltd of Reading, England, it was a "cam and roller" system in which the non-constant pitch of the cam resulted in a variable steering ratio, with the lowest gearing being at the straight ahead, rising rapidly to either lock. The rise in gearing (equivalent to a drop in ratio from 21.6:1 to 13:1) occurred almost entirely within the first half turn of the steering wheel from the straight-ahead position. The effect was to give very light and relaxed steering at the straight ahead, with quick reaction when cornering. There was no adjustment in the behaviour of the steering in reaction to road speed. A very few of the last S-Types were similarly equipped.

[johngosnell]

The change to power steering was done long before I bought the car, when I get the opportunity I will have it put on a a lift and see how the change was done. The car had a major restoration in the early 1990's so I suspect it was changed then along with the neg earth mods. As you will know over time I have banged on abought tightening the power steering But now knowing it has the Adwest box It looks as if I will have to get it rebuilt because it definitely does not adjust at different speeds .

Regards John


1B1257BW

Edit,
I have just read an article on the Adwest Veramatic box and a major criticism of the box was the light vague feeling at speed, so after all this time I guess that there is nothing wrong with the box at all.