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There is a possibility that there are two end caps. Both with the return pipe at the top but one with the feed pipes going to the bottom in the case of the S Type RHD and one for the 420 and LHD cars.
For adjustment there are two screws that you can turn to tighten up any play. There is one on top with a locking nut and on the left side (Making it impossible to get to on a RHD car without removing the steering box or removing the engine.) there is a grub screw which pushes against a mushroom shaped metal bar that in turn pushes up against the worm drive cutting out any play.
Yes, the sector screw was correctly set when I took delivery of the box (and of course I've played with it since). As I understand it the second one adjusts free motion between the drive from the power piston to the sector, so the assistance comes in nicely.
All the Jaguar literature covers play at the drop arm end of the system and doesn't consider the input end. Because the worm is much more efficient in the one direction (driver to road wheel) than the other, that doesn't detect any wear on the input end.
If you look at the end of the input shaft (second photo in Cass's post timed at 9.03am), there appears to be one shaft inside another. The outer is the splined input and (I think) the inner is the end of the torsion bar. A pin (obscured in the photo by the alignment disc) joins the two together. If I gently rotate the outer splined shaft, there's just detectable movement of it relative to the torsion bar.
I don't think there should be lost motion there. But Jaguar doesn't tell you to check for it. And early PAS systems (prior to the introduction of the torsion bar) used such play to operate the valve to apply the assistance. Though it seems unlikely to me, it's not totally impossible that Adwest designed it in to make the system work more smoothly. Anyway, unless someone tells me otherwise, my intention is to replace the pin (or have a machine shop do it for me).
I should now apologise as we're taking the thread a bit off topic.
Yes, there was play there and in a UJ. I decided against using any of the 420 column that came attached to the box. There's a pin that connects the splined input shaft to the torsion bar. I suspect the wear is between the pin and the torsion bar. Of course, all that is assuming a small amount of lost motion isn't intentional.
Interesting. The problem usually lies in the worn nylon rollers in the CV joint. And your present lower column actually reaches the splined input shaft of the Varamatic box? There are varying lengths of lower columns dependent on steering box used.
Last edited by Glyn M Ruck; Mar 30, 2024 at 03:01 PM.
Interesting. The problem usually lies in the worn nylon rollers in the CV joint. And your present lower column actually reaches the splined input shaft of the Varamatic box? There are varying lengths of lower columns dependent on steering box used.
The present lower column shouldn't fit. I've not decided exactly what to do. There are several possibilities for making up column sections. Putting the steering together is still a long way ahead. Also, looking at the size of the steering box, some small modifs to the adjacent channel sections might be required.
The motor sport and kit car suppliers have a good range of parts for steering columns including adjustable sections. Hopefully they'll not have all been put out of business before I reach that stage. When the body is more advanced, I'll take the engine out and do some trial fitting. For the moment, the engine provides a useful counter weight for keeping the body aligned.
Some early cars had this rubber gubbins at the top of the lower column & twin UJ's.
My Mk2 has the rubber thing. It has survived over 60 years, shows no signs of failing, and seems to still work perfectly. On the other hand, being rubber, it could be much more brittle than it looks and suddenly crack into several pieces ... .
Rob - that makes a lot of sense. I guess I'll find out more when I get around to taking mine apart. I hadn't initially planned to dismantle it as it seems quite dry and clean and I can adjust out the play at the drop arm. However, there's a small amount of lost motion at the input shaft. I'd guess it would amount to 5mm at the perimeter of the standard steering wheel. I appreciate it's almost negligible, but it's sufficient to make me want to find the source.
I find most of the info in the old service manuals to be excellent, but there's the odd item that's either missed or seems to have been written by someone who never actually took the item apart. The section on Varamatic boxes seem to fall into the latter category.
JJSandSMS - the usual sources for these boxes and associated gear in the UK are eBay, Jaguar breakers and secondhand parts dealers, and ads in the Jaguar Clubs. I'd guess that you'd have to follow the same sort of route in the US. UK eBay has a couple at present, but transport to Florida might be prohibitive due to the weight.
I'm reviving this old thread to close out a comment I made on my Marles Varamatic box. I mentioned that it has a small amount of play between the splined input shaft and the input end of the torsion bar. I've since discussed this with Ken Jenkins of the JEC. He says that, provided it's small, it's normal and reduces when the box is full of fluid under pressure. Something not to worry about, but it would have been nice if it had been mentioned in the service book.
