So I'd rather keep my ser 2 front subframe if it's feasible, can I just change the knuckle/hubs and caliper/rotor assemblies to series 3? Looks like they should bolt up to the control arms the same, or are the control arms improved over the ser2? I have to completely disassemble it all anyway and powder coat, and the sway bar, steering rack, rotors and calipers are going to be changed anyway. Opinions appreciated.
Bill

 

Same, same.

All I know, and it has never been verified, the actual steering arms were altered for S3. Something to do with "angle of turn in"???

The XJS also has the same components, but the steering arm discussion never comes up, even when I was at Jaguar Spare Parts.

The actual cradles were different, 6 to V12, BUT, that was the real early cars (Carby), and ONLY to do with 4 nuts welded into place for the V12, coz access with the engine in there was zero. The cradles very quickly ALL became the same spec, made sense, even to me.

I have used whatever cradle I could steal whenever I wanted one, never bothered to check what it came from.

 

There was a change in the Series III XJ6 upper control arms, circa 1983...but it was only to alter the geometry a bit. Nothing that would have any bearing on your plan. Just don't mix-n-match the earlier arms together with the later ones. That is, use all four early style or all four later style.

From memory, the early style Series III XJ6 arms are the same as Series II XJ6.

Cheers
DD

 

Would the larger axle stubs and bearings be a big improvement? The car won't be raced, maybe some brisk touring laps once in a while. As I think about it, the Broadspeed coupes used the series 2 front suspension, bearings and all, and I don't recall issues with wheels coming off or anything. Maybe the racing program is where they found a bit better geometry? If the ser2 has vented front rotors this all may be a solution looking for a problem? This car had really good brakes as I remember.

 

Also, are all the v12 and xk engined xjs front sway bars the same? That may be a worthwhile upgrade. Working on my XJ6c btw...

 

In 2021 I put an XJS V12 front subframe under my Series 2, it came with Bigger sway bar, 3/4" as opposed to 5/8".
https://www.jaguarforums.com/forum/x...2/#post2361894
I noticed right away much flatter cornering and far less body roll. I like it. Although I will say it changes steering somewhat, as might be expected with less body roll.

Only change was bigger sway bar bushings needed for the font mounts.
As you've got access to a bigger bar, Go For It!!
EDIT:
By the way, Everyone here knows how I drive.
"Brisk" doesn't cover it. And most here know that I'm addicted to Cornering Gs.
And, after I put on the semi-metallic pads that Doug recommended, it stops on a dime and gives 9 cents change.
/Edit
(';')

 

Hi Elinor, thanks for the info, I think our driving styles may be pretty close.

 

I thought all the Series II cars did have the vented rotors....but the coffee isn't done brewing yet so anything I say is suspect at the moment

I wouldn't worry about wheel bearing size, personally. Jaguar obviously had a reason for the change but what actual real world improvement are you likely to see? None.

As the years go by I've become more selective about upgrades. Sometime they're really useful. But, as often as not, the juice ain't worth the squeeze. And....maybe I'm just getting a bit lazy

Cheers
DD

 

For the longest time the V12 sedans used the same front bar as the XJS.....which was bigger than the bar used on the 6-cyl sedans, as already stated.

Circa 1988 some XJSs were built with a 1" front bar as part of the "Sportpack Suspension". NLA from Jaguar and hard to find second hand

Jaguar used a rear anti-roll bar on some XJSs as well. This can be installed on a sedan with a little effort. Makes quite a difference

Cheers
DD

 

I think I'll do that rear bar Doug, sounds like a good idea. Really made a difference on my 71 vette.

 

Re: Rear Sway bar...
I often refer to the Olde Chrysler I had once, the car that taught me so much about Life, the Universe, and Everything that's important in the shop. It was 9 blocks long (22 feet), a block wide (nearly 6 feet inside!)looked like it was doing 75 sitting at the curb. During my ownership it was completely refurbished from stem to stern. >sigh<

Over in one of the local wrecking yards appeared a bashed Ex-Highway Patrol cruiser of the correct vintage, so I promptly snagged the rear sway bar from it and screwed it to the back axle of my Chrysler, which was a Very soft Mercan Barge with factory marshmallow suspension, fit for M'Lady Plushbottom in all her finery.

The results were nothing short of Staggering for one as inexperienced as I was then! A Large portion of the Mercan Barge Understeer and Plowing was Gone! It drove more like I imagined a European Saloon. Steering became almost crisp! It certainly went where I pointed it for a change.

In fact, transition from that to Wart, 2002 Ford Windstar minivan that I drove right after was Shocking!
But I digress..........

In 2015 when we were rebuilding Nix's front suspension the FIRST time, husband thought it would be a great idea to install an XJS rear sway bar as he liked the result on my Chrysler and went In Search Of one. Couldn't find one, even in a nation-wide search. (we didn't know about the difference with a V-12 front bar so that wasn't considered)

Then he read somewhere in one of his sports car magazines that if one installed such an upgrade, one must beware of a tendency to swap ends in the blink of an eye! That did Not sound to me like a good idea, having grown up as I did driving on ice and snow where that could happen on a normal day! So we ditched that idea and cancelled the search.

Anyway, the addition of the XJS sway bar has made Such a difference, I don't think in hindsight I want to fool with a rear one now anyway.
(';')

 

It IS possible to go overboard with the size on a rear bar….. with bad results.

Jaguar used two sizes, 12mm and 14mm ( or something like that). That’s in the small side…, but that’s OK. They work.

There are/ were some aftermarket choices that were more like 20mm and are a bit much and can create some scary situations!

Cheers
DD