Pardon my ignorance and I have not looked at the ratios for each iteration, but wouldn't a lower ratio be desired for more precise steering input?

Are the racks interchangeable without modification for all MYs?

 

I never said higher or lower?? Just faster... less turns lock-to-lock...

At this point in time I cannot tell regarding the interchangeability between model years (actually it's just a cutoff point, the 4.2 and the 5.0)

Although there is also a crossover into the XF as well, the XFR-S and the XKR-S have the same steering rack.

EDIT

OK i've been informed that all the XK racks are interchangeable. And that it's a typo in the JEPC about the 4.2 XKR-S having a different rack.

 

Sorry I misread faster ratio as higher ratio which would be the opposite of what I would want, I would like a lower ratio to make the steering a bit heavier but quicker to respond.
So if they are all interchangeable, then does that mean the GT one from the F-type would work on the 4.2?

 

The information I got today was that the racks are interchangeable between the 4.2, 5.0 and GT X150's... so the F-Type rack (i.e. the GT one) will also fit in a 4.2.

 

Very interesting. So basically the whole front suspension subframe assembly from the F-Type went into the XKR-S GT, with the exception of the height-adjustable shock/spring setup. Is there anyway to know if the rear floor pan is different from the regular XKR?

 

Any idea what the various ratios are? So far I have found the 2008 XKR is 17.1:1 and the 2014 F-type is 14.6:1

 

I see a couple of different part numbers for the F-type steering rack though T2R1327 appears to be the one I would want, there is a T2R1327E for around $1K USD and also T2P1051 with 3 variations as well.

 

Didn't Jaguar switch from hydraulic to electric steering at some point?

 

2016

 

Wow that's quite a difference!

T2R1327 is the LHD rack from the XKR-S GT / F-Type.

The T2R1327E is an exchange/rebuilt version, there will be a surcharge on top which is refunded if you give them one in exchange.

T2P1051 is the RHD rack from the XKR-S GT / F-Type.

 

Found something interesting about the front vertical links "steering knuckles" in one of the technical manuals...

NOTE: XKR-S vehicles use specially designed wheel knuckles that provide increased camber and castor stiffness to improve the accuracy and weighting of the steering for greater levels of feedback and precision.



There are also different wheel alignment specifications for the XKR-S and those cars fitted with "Dynamic Pack", for both 4.2 and 5.0 cars...

So the 2008 XKR-S and XKR Portfolio's have a different alignment to the regular 4.2 XKR...

EDIT

I have not been able to find any images of the steering knuckles of the XKR-S GT, however this is a good explanation http://www.philip-james.co.uk/portfolio/project/ they are machined from billets of aluminium

 

Is that a difference that I would notice to justify going through the process?

Thank you for the clarification on the part numbers. I found a company that sells remanufactured steering racks for a considerable savings however they can only tell me it is for the LHD F-Type 2014-2015 they can not confirm the part number. Would you consider that too risky?

And finally, are there any other bits and pieces I would need for the installation or is just the rack enough as I can probably reuse the links.

 

There is more to it than just the rack ratio, the XKR-S has the different steering knuckles as well, there are probably some other differences to the front end as well, I haven't been through every little detail yet.

It'd be nice to know what the ratio's of the regular XKR-S models are as well. I'll see what I can find.

There is only one type of hydraulic rack on the 2014/2015 F-Type, so it should be pretty straight forward. If you can get some pictures of the tag on the rack, it might help to confirm the version.

There is one specific item for the XKR-S GT listed, the lower steering column shaft/swing link. It's a unique part number, not the same as the XKR, XKR-S or F-Type.

Item #2 in the drawing;



Why it's different for the GT is unclear to me.

Also for the regular XK models there are different versions for different VIN ranges, without supercessions.

I would think that the end links from the XKR would fit straight on to the F-Type rack.

You've gotta remember, no-one outside of the factory has done any of this stuff, so there's no how-to-guide...

 

I asked them about the stamped numbers on the rack but they claim they were removed during the re-manufacturing process, specifically after it is media blasted, that is what has me hesitating. It has all new seals, dust covers and anything else needed and fully inspected, measured and tested to meet new spec. Price is under $800 shipped and comes with a 3 year warranty. They guarantee it is a genuine Jaguar F-type rack for 2014 & 2015.

I know the R-S has more substantial knuckles but I am not clear on how much of a difference that would make with regards to steering feel and if any to the ratio.

What difference would the column shaft make on anything?

 

If they guarantee it, there's not much more you can ask for I guess....

The R-S vertical links / knuckles provide "increased camber and castor stiffness to improve the accuracy and weighting of the steering for greater levels of feedback and precision" I don't think they would go to the expense of creating special parts just for bragging rights, especially since it's never mentioned in any marketing literature, just buried away in a technical manual.

I really don't know what the story is with the steering column on the GT. The bottom universal joint (#1 in the drawing) is not listed as being a special part. But there are different versions for regular XK and XKR-S. And there are also different versions by VIN range. Actually for one of the VIN ranges the XKR-S has the same knuckle #1 as the X351 XJ and the X250 XF...

 

I have no doubt of that but how much of a difference to be that appreciable v. cost & effort? I mean increasing or decreasing the amount of air in the tires can also have an impact on steering response. And are the knuckles even available?

 

OK the story of the steering column is that the XKR-S GT got a different version because of safety reasons, in case of a high-speed impact, it collapses in a slightly different way to the regular XK ones... there is no difference in the compatibility of the steering column, physical dimensions are the same.

As for the XKR-S knuckles, yes you can buy them, the part numbers are valid, they cost about $100 more each than the standard version. I don't know how much of a difference they make in real world terms...

 

Now this is interesting, got hold of the wheel alignment specifications for the XKR-S GT, when you compare the settings to the regular XKR-S, they definitely set it up with the track in mind, not street driving...

Whereas the regular XKR-S has assymetrical camber settings depending on if it's a LHD or RHD car, the RS-GT has symmetrical settings.

The data in order to make a sensible comparison between the settings of the XKR, XKR-S and XKR-S GT is spread out over 6-7 pages, i'll see if I can get it all into one spreadsheet.

 

Quick show of hands, who would be interested in an XKR-S GT bonnet?

You would have to cut/weld the vent panels in to an XK bonnet



I'm talking with a local supplier about having the vent sections made up, but the tooling costs a bit, so need to know how many people would be interested.

Assume it to be $700 plus shipping for the pair of panels.

 

No rush but have you had a chance to put this together?

I do have the new GT/F-Type rack in hand and will be installing it as soon as I sort the EPB issue.