Modified Jaguar IRS setup

This is my 1st post, so be patient with me.
I’m trying to find a source of information regarding a picture I’ve seen on the internet of a modified XJ40 centre and hubs mated to XJ6 arms.

I will try to attach this picture later.
I’m not seeing how that can be achieved just yet, so if no picture when I post, please dont hestitate to offer a helping hand.

It seems your/our member Slick11 may have some knowledge of this project, but I have not been successful in making contact with him.
Allbeit, that he did not build it…

Any help or guidance in direction would be most appreciated, as I have a yerning to give something like this a try, however starting from ground zero seems pointless if it has been done before!!!

Many thanks, Rusty

Interesting! What project is it that you are doing this on?

I just happen to have what seems to be right suited left over components that just got my curiousity going.
I do however have an old pickup truck that could benefit from a Jaguar style ride in the rearend.
Or, maybe I just have too much time on my hands these Covid days…
All the same I would really like to know more, as I respect people who are capable of thinking outside the box.

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Well, I commend your inventiveness!

The Jag IRS has been used in many a hot rod and resto mod, and although it’s relatively complex, on a pickup truck, you arent going to see a great increase in any kind of performance or handling.

However, it will look really cool!

I’m sure somebody, somewhere has used that particular rear end set up in a hot rod, so I would just do some searching around on YouTube and on the Internet, and you’re bound to have found someone who has utilized it.

I know my way around Jag IRS and what this guy has done if quality is up to scratch is out of the box.
A Jag IRS ride has got to be heaps more comfortable than a late 1950’s leaf spring setup, especially when the pickup box is empty.
I accept the taller gears, but I have a V8 engine and can always play with tire diameters a little.
But, right now it is more about respecting what he has done…

A quick analysis of the picture tells us that he has used:

  1. a XJ40 style centre section.
  2. a cut off piece from the XJ6 cage to pickup the lower arms.
  3. lower arms are XJ6 or similar.
  4. XJ40 hubs, since there are no inboard disc brakes etc.
  5. a belly plate from something but I’m not able to ascertain what!

What I’m curious about initially is:

  1. how has he attached the XJ6 lower arms to the XJ40 centre.
  2. how is the XJ centre attached to the chassis or frame of the vehicle it is mounted in?
  3. how has he attained enough support to ensure strength at attachment points?

Keep in mind the very last of the XJS cars eliminated the inboard disc brakes and moved them outboard to conform with the XJ40 sedans being built at the time. Do not know what if anything changed with the subframe cradle at this point.

Not sure 100%, but I may have owned one of those XJS rearends.
They use an odd cast lower arm of a oval section almost and only 1 spring per side.
The spring sits in a pocket cast into the arm.
They are also around 60mm wider than the XJ40 IRS etup.
I know they employ larger disc calipiers and use vented rear disc brakes.

Are we talking about the same thing???

Does anybody on here know “Slick11” off the forum???

I’m just wondering if there maybe an other Forum that is better suited to my questions???
Can anybody offer something please???

Let’s recap…

Many people on these forums don’t check daily, and some of them don’t even check weekly. Just keep checking back every once in a while, and if anything can be offered, it will be.

His user ID pops right up with the search function. You can send him a PM from there.

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For the benefit of future archive searches, lots of misinformation in this summary.

Note ; Not trying to be argumentative, only helpful.

Fair enough: what in the thread is misinformative?

Outboard brakes went solid first then vented and never seen an XJS with one spring per side, etc. Thanks

Thanks for the calming words, I accept that, moreover just concerned that Slick11 does not visit much at all…

Thanks Mike, I will try to work out that PM thing and send him a message…
Thanks for your reply.

I dont agree, but you are sure entitled to your perspective on this topic.
If it does develop, I’m sure that you will see otyerwise.

Here is one XJS IRS assembly with a single spring each side, has outboard vented disc brakes, a truss style rear support and is approx 60mm wider than the XJ40 of the same era.
Oh and the lower arm is not a pressed metal item as used in the XJ40, it seems to be cast…

XJS kjeerzu

That looks like a XJR (X308) rear end to me.