Hello all, I'm looking at a way of potentially simplifying replacement of the front rotors on my car for next time I have to do them. I think it's ludicrous to have to pull the hub to change them. Does anyone know if it would be possible to use hubs from the DB7 or XJ40 on our cars?

 

You can change the front discs without removing the hubs. This is easier if you remove and chuck the OEM dust shields from behind the disc, but quite possible if you keep them, as there is an access hole in them for this purpose.
You just apply the ratchet and socket to the disc securing bolts from the back of the disc, and ask you helper to hold the discs on the brake, or jam the hub with a long bar between the wheel studs.
Greg

 

Don't think so Greg, Hub can be changed without removing brake disc but you can not remove disc with hub in place.
However considering how often a disc change might be required I don't see any problem with the stock setup.

 

Baxtor
A rare occasion when we disagree! I have actually done it, several times, and it is the recommended procedure in at least one of the manuals I have read. Cannot recall which one. Admittedly it is far easier to remove the hub!
There is access from the rear of the disc, forward side of the suspension and you can revolve the hub to a certain place get the socket in on each disc securing bolt.
Greg

 

I agree it can be done!

Not sure about the DB7 question.

IMHO, replacing brake rotors is a good time the remove the hubs for a good cleaning and bearing repack...an oft-neglected service item

Cheers
DD

 

Greg, parts we agree on, parts we don't. I have detached those bolts on many occasions in the manner you detail, but separating the disc from the hub will just leave you with a loose disc captive on the stub axle in between the hub and suspension upright until such time you remove the hub. The disc attaches to the back face of the hub and with the hub in place there is no way to remove the disc.
The OP wanted to change the discs.

 

Many apologies, Baxtor, you are 100% right, I did not follow that bit, even though it was clear enough in your first reply. As you say, you can remove the hub without the disc, but not the disc without removing the hub first.
Of course, it is easier to remove the hub if the disc is removed first, as then you do not have to undo the caliper, I think that was what I must have had at the back of what passes for a brain at my age! Thanks for putting me right.
Greg

 

Not a problem Greg. I am a bit reticent at putting anybody right lest I come across as a smart ar**. Given your experience (and ageing brain) it was obviously a misread of the original post.

 

If only... Sadly, just stupidity accounts for it, I had to look at a photo of the thing before the penny dropped!
Greg

 

Couldn't you undo the stubaxle from the hubcarrier part? Afaik it is only one nut!?

 

Removing the stub axles I have heard is very difficult.

FYI 6 cylinder db7 have exact same brakes and hubs as the abs xjs. The v12 db7 has some fancy larger brembo disc which were also on other high performance cars at the time, can't remember which ones off the top of my head. However they are extremely pricy for the calipers, rotors, and pads. They use the same hubs as the abs xjs.

The xj40 uses a different brake and hub assembly, it is not a bolt on job. You would have to make some custom parts to make it work. The only advantage would be you could put on x308 xkr or xkr brembo brakes as a brake upgrade.

 

To complicate things further I have a 1989 with ABS and when I rebuilt the front end I bought bearings and seals for an 89 XJS, guess what, yep they didn't fit, I ended up using XJ40 seals.

Removing the stub axle is a PITA and requires removal of the hub prior. I had to use a VERY BIG hammer with the upright removed to get them out.

 

Astonishing coincidence, but here it is a conversion offered:
JAGUAR XJ. XJS .V12 ASTON VANTAGE 2000 MODEL CONVERSIONS. | eBay


Greg

 

Wow serious cost, as much as the car its self

 

That is some serious money, I can honestly say in the last 40 years I have never found the brakes on a Jag wanting.