Hey guys,

I can't remember who it was, who said about it, but it was about fitting the better and less crack-prone rear hub carriers from an XJ40 (which are AFAIK identical to X300 and X308) to an XJ-S. Something about some machining or somwas required.

As I have a full X308 axle sitting here waiting to be torn apart, is it worth looking into this? I have not yet seen any cracks on my XJ-S carriers... So what is involved and is it worth it?

Cheers

Damien

 

It was me. I had an XJ40 rear end. The hub carriers do fit with some slight modifications. The lower fulcrum shaft is thinner than the XJS so the XJS LCA will need to be bushed for the X308 fulcrum shaft. The hub carriers I had also had toe adjustment, something the XJS does not have.


You could also modify the handbrake to work on the OB brakes use what Jaguar did on the OB brak XJS and it will work.

 

If you have the X308 axle, you can use the 308 halfshafts with the spacer. Then you can use the 308 hub with the original XJ diff. This is basically what Jaguar did with the late XJS with outboard brakes.


I was told by a friend of mine who is quite involved with vintage racing in the UK that the early XJ40 hubs were prone to cracking when used in racing, and the preferred hub was from an XKR. I have no idea how or if an XKR hub is different from an X308.

 

I think you mean XJR. XK8/XKR is a totally diffrent design.

 

Nope, he specifically said XKR. I questioned it at the time. That being said, I have never looked at an XKR hub, but he's a person who's opinion I trust and he knows his stuff.

 

The X100 (XK8/XKR) has te same rear axle as the XJ40, X300 and X308.

 

Hey Warren,

thanks. I thought it was you, but i wasn't sure. I would keep the standard inboard brakes IF I did this.

Would it be easier to widen the holes in the hub carrier to take the factory fulcrum shaft instead? And what about the ABS setup? I've seen that my hubs have two different mounting points... I have yet to look at the rear sensors and sensor rings but should be possible.

Did you use the XJ drive shafts?

 

A timely post as I asked about cracked hubs a few days ago. Is this a common thing with the V12's torque?

 

Happens more with the weight of the car, and how it was driven in the past. Obviously track days are harder on suspension components than normal street driving.


I'd get another used hub that is the same and replace that cracked hub. You'll probably have to recalculate the shim size for the bearing preload, as each hub can be a bit different.

 

I don't think opening the hole in the hub is doable because of the bearing size. Much easier to use XJ40/300 fulcrum shaft and bush the XJS LCA.



I do know that the width of the hub at the lower fulcrum fits the XJS LCA.


I did not check driveshaft length. I did check the spacer that fits between the driveshaft and diff which was about the same thickness as the XJS disk.


I also did not check ABS sensor or reluctor ring. I understand these are different, but I do not know exactly what differences. BUT as long as the number of teeth are the same it might work.



I started to look at what was required before I moved but put everything on hold, unfortunately my hubs disappeared.